Search

Search Results

• 1. [Image] Investigation of Two Areas in New York State which may have Potential for Geothermal Energy. Progress Report, May 1, 1976--September 31, 1976

  	Significant results to date include the following: (1) the present Adirondack Mountains Dome is undergoing rapid contemporary vertical doming; the velocity at the center of the dome is 3.7mm/yr, compared ...
  	Citation × Citation Citation Abstract Copy Title: Investigation of Two Areas in New York State which may have Potential for Geothermal Energy. Progress Report, May 1, 1976--September 31, 1976 Author: Isachsen, Y.W. Year: 1976 Significant results to date include the following: (1) the present Adirondack Mountains Dome is undergoing rapid contemporary vertical doming; the velocity at the center of the dome is 3.7mm/yr, compared to 1mm/yr for the Swiss Alps; (2) post-Pleistocene fault offsets measuring from one to eleven millimeters have been found in the Adirondacks, indicating vertical uplift during the past 10,000 years; (3) the Panther Mountain Circular drainage feature is structurally-controlled and shows a 10 to 20 milligal negative Simple Bouguer gravity anomaly such as might be produced by a buried felsic pluton Title: Investigation of Two Areas in New York State which may have Potential for Geothermal Energy. Progress Report, May 1, 1976--September 31, 1976 Author: Isachsen, Y.W. Year: 1976 Significant results to date include the following: (1) the present Adirondack Mountains Dome is undergoing rapid contemporary vertical doming; the velocity at the center of the dome is 3.7mm/yr, compared to 1mm/yr for the Swiss Alps; (2) post-Pleistocene fault offsets measuring from one to eleven millimeters have been found in the Adirondacks, indicating vertical uplift during the past 10,000 years; (3) the Panther Mountain Circular drainage feature is structurally-controlled and shows a 10 to 20 milligal negative Simple Bouguer gravity anomaly such as might be produced by a buried felsic pluton Close

• 2. [Image] Stratigraphy and Alteration, 15 Shallow Thermal Gradient Holes, Roosevelt Hot Springs KGRA and Vicinity, Millard and Beaver Counties, Utah

  	Fifteen shallow thermal gradient drill holes were recently completed by Geothermal Power Corporation (GPCR) in the vicinity of the Roosevelt Hot Springs KGRA. Five holes penetrated Tertiary granitic rocks ...
  	Citation × Citation Citation Abstract Copy Title: Stratigraphy and Alteration, 15 Shallow Thermal Gradient Holes, Roosevelt Hot Springs KGRA and Vicinity, Millard and Beaver Counties, Utah Author: Hulen, J.B. Year: 1978 Fifteen shallow thermal gradient drill holes were recently completed by Geothermal Power Corporation (GPCR) in the vicinity of the Roosevelt Hot Springs KGRA. Five holes penetrated Tertiary granitic rocks and Precambrian gneiss east of the KGRA. Seven holes completed entirely in alluvium near the southwestern corner of the KGRA encountered a near-surface marker horizon of Pleistocene pumice and perlite. Maximum calculated alluvial sedimentation rates since initial deposition of this pumice and perlite range from 1 foot in 12,500 years to 1 foot in 2,300 years. Three holes east of the Mineral Mountains penetrated late Cenozoic basaltic andesite beneath a thin veneer of alluvium. All 15 GPCR drill holes appear to be peripheral to a central zone of anomalously high thermal gradient and low resisitivity delineated by previous investigations. GPCR-8 and -14, however, are characterized by high heat flow and relatively abundant manganese oxide mineralization, which may reflect a favorable hydrologic system controlling thermal fluid flow at depth. These holes thus seem most encouraging for discovery of a deeper high-temperature geothermal resource Title: Stratigraphy and Alteration, 15 Shallow Thermal Gradient Holes, Roosevelt Hot Springs KGRA and Vicinity, Millard and Beaver Counties, Utah Author: Hulen, J.B. Year: 1978 Fifteen shallow thermal gradient drill holes were recently completed by Geothermal Power Corporation (GPCR) in the vicinity of the Roosevelt Hot Springs KGRA. Five holes penetrated Tertiary granitic rocks and Precambrian gneiss east of the KGRA. Seven holes completed entirely in alluvium near the southwestern corner of the KGRA encountered a near-surface marker horizon of Pleistocene pumice and perlite. Maximum calculated alluvial sedimentation rates since initial deposition of this pumice and perlite range from 1 foot in 12,500 years to 1 foot in 2,300 years. Three holes east of the Mineral Mountains penetrated late Cenozoic basaltic andesite beneath a thin veneer of alluvium. All 15 GPCR drill holes appear to be peripheral to a central zone of anomalously high thermal gradient and low resisitivity delineated by previous investigations. GPCR-8 and -14, however, are characterized by high heat flow and relatively abundant manganese oxide mineralization, which may reflect a favorable hydrologic system controlling thermal fluid flow at depth. These holes thus seem most encouraging for discovery of a deeper high-temperature geothermal resource Close

• 3. [Image] A new model for the formation of Crater Lake Caldera, Oregon

  	ill. (some col.), maps ; Thesis (Ph. D.)--Oregon State University, 1972; Includes bibliographical references
  	Citation × Citation Citation Abstract Copy Title: A new model for the formation of Crater Lake Caldera, Oregon Author: Lidstrom, John Walter Year: 1972, 2008 ill. (some col.), maps ; Thesis (Ph. D.)--Oregon State University, 1972; Includes bibliographical references Title: A new model for the formation of Crater Lake Caldera, Oregon Author: Lidstrom, John Walter Year: 1972, 2008 ill. (some col.), maps ; Thesis (Ph. D.)--Oregon State University, 1972; Includes bibliographical references Close

• 4. [Image] The 1980-1982 Geothermal Resource Assessment Program in Washington

  	Since 1978, the Division of Geology and Earth Resources of the Washington Department of Natural Resources has participated in the U.S. Department of Energy's (USDOE) StateCoupled Geothermal Resource Program. ...
  	Citation × Citation Citation Abstract Copy Title: The 1980-1982 Geothermal Resource Assessment Program in Washington Author: Korosec, M. A. Year: 1983 Since 1978, the Division of Geology and Earth Resources of the Washington Department of Natural Resources has participated in the U.S. Department of Energy's (USDOE) StateCoupled Geothermal Resource Program. Federal and state funds have been used to investigate and evaluate the potential for geothermal resources, on both a reconnaissance and area-specific level. Preliminary results and progress reports for the period up through mid-1980 have already been released as a Division Open File Report (Korosec, Schuster, and others, 1981). Preliminary results and progress summaries of work carried out from mid-1980 through the end of 1982 are presented in this report Title: The 1980-1982 Geothermal Resource Assessment Program in Washington Author: Korosec, M. A. Year: 1983 Since 1978, the Division of Geology and Earth Resources of the Washington Department of Natural Resources has participated in the U.S. Department of Energy's (USDOE) StateCoupled Geothermal Resource Program. Federal and state funds have been used to investigate and evaluate the potential for geothermal resources, on both a reconnaissance and area-specific level. Preliminary results and progress reports for the period up through mid-1980 have already been released as a Division Open File Report (Korosec, Schuster, and others, 1981). Preliminary results and progress summaries of work carried out from mid-1980 through the end of 1982 are presented in this report Close

• 5. [Image] Petrographic Analysis and Correlation of Volcanic Rocks in Bostic 1-A Well near Mountain Home, Idaho

  	Detailed examination of volcanic rock cuttings from the Bostic I-A well near Mountain Home, Idaho, provides data that correlate the stratigraphy of the well with the regional stratigraphy of the western ...
  	Citation × Citation Citation Abstract Copy Title: Petrographic Analysis and Correlation of Volcanic Rocks in Bostic 1-A Well near Mountain Home, Idaho Author: Arney, B. H. Year: 1984 Detailed examination of volcanic rock cuttings from the Bostic I-A well near Mountain Home, Idaho, provides data that correlate the stratigraphy of the well with the regional stratigraphy of the western Snake River Plain. The Bostic I-A well penetrates basalt of the Middle Pleistocene Bruneau Formation and underlying sedimentary rocks of the Upper Pliocene Glenns Ferry Formation. Basalt underlying the Glenns Ferry Formation is most likely Banbury Basalt of Middle Pliocene age or Banbury equivalent. A 350-ft interval of felsic volcanics is then intersected above another 600 ft of basalt. The well bottoms in altered felsic volcanics Title: Petrographic Analysis and Correlation of Volcanic Rocks in Bostic 1-A Well near Mountain Home, Idaho Author: Arney, B. H. Year: 1984 Detailed examination of volcanic rock cuttings from the Bostic I-A well near Mountain Home, Idaho, provides data that correlate the stratigraphy of the well with the regional stratigraphy of the western Snake River Plain. The Bostic I-A well penetrates basalt of the Middle Pleistocene Bruneau Formation and underlying sedimentary rocks of the Upper Pliocene Glenns Ferry Formation. Basalt underlying the Glenns Ferry Formation is most likely Banbury Basalt of Middle Pliocene age or Banbury equivalent. A 350-ft interval of felsic volcanics is then intersected above another 600 ft of basalt. The well bottoms in altered felsic volcanics Close

• 6. [Image] Seeking refuge: making space for migratory waterfowl and wetlands along the Pacific Flyway

  	Abstract "Seeking Refuge" examines the history of migratory waterfowl management along the Pacific Flyway, the westernmost of four main migration routes in North America. Drawing on approaches from historical ...
  	Citation × Citation Citation Abstract Copy Title: Seeking refuge: making space for migratory waterfowl and wetlands along the Pacific Flyway Author: Wilson, Robert Michael Year: 2003, 2005, 2004 Abstract "Seeking Refuge" examines the history of migratory waterfowl management along the Pacific Flyway, the westernmost of four main migration routes in North America. Drawing on approaches from historical geography and environmental history, this study shows how wildlife officials developed migratory bird refuges in Oregon and California, where over 60 percent of Pacific Flyway waterfowl winter. During the early-twentieth century, reclamation and river diking eliminated most of the wetlands in the birds' wintering range. Bird enthusiasts such as bird watchers and duck hunters successfully lobbied for the creation of wildlife refuges in a few areas along the flyway. These early refuges failed to protect waterfowl habitat and they were severely degraded by reclamation. In the 1930s and 1940s, the U.S. Fish and Wildlife Service (FWS) and its predecessor, the Bureau of Biological Survey, undertook an ambitious program to resurrect these sanctuaries and to create new ones. Many farmers opposed these refuges out of fear that waterfowl would damage crops. To respond to these concerns and to ensure an adequate food supply for the birds, the FWS raised rice, barley, and other grains. The agency adopted many of the technologies of modern, industrial agriculture including synthetic herbicides and insecticides such as 2, 4-D and DDT. By the 1960s, the refuges had become largely mirrors of the surrounding irrigated farmlands, the main difference being that the FWS raised grain for waterfowl rather than for market. Refuges could not escape the agricultural settings in which they were embedded. As units within the irrigated countryside, Pacific Flyway refuges were often at the mercy of nearby farmers and federal reclamation agencies. Poor water quality and insufficient supplies of water often hampered FWS efforts to manage refuges. In the late-twentieth century, reduced water supply due to diversions to California municipalities and to sustain endangered fish species affected the amount of water reaching refuges. This dissertation has other goals. First, it critiques the anthropocentrism of most historical geography by focusing on how political, cultural, and ecological factors affected wildlife. Second, it contributes to the literature on the state's role in environmental protection by investigating the overlapping, and often contradictory, spaces within which wildlife managers implemented environmental regulations. Title: Seeking refuge: making space for migratory waterfowl and wetlands along the Pacific Flyway Author: Wilson, Robert Michael Year: 2003, 2005, 2004 Abstract "Seeking Refuge" examines the history of migratory waterfowl management along the Pacific Flyway, the westernmost of four main migration routes in North America. Drawing on approaches from historical geography and environmental history, this study shows how wildlife officials developed migratory bird refuges in Oregon and California, where over 60 percent of Pacific Flyway waterfowl winter. During the early-twentieth century, reclamation and river diking eliminated most of the wetlands in the birds' wintering range. Bird enthusiasts such as bird watchers and duck hunters successfully lobbied for the creation of wildlife refuges in a few areas along the flyway. These early refuges failed to protect waterfowl habitat and they were severely degraded by reclamation. In the 1930s and 1940s, the U.S. Fish and Wildlife Service (FWS) and its predecessor, the Bureau of Biological Survey, undertook an ambitious program to resurrect these sanctuaries and to create new ones. Many farmers opposed these refuges out of fear that waterfowl would damage crops. To respond to these concerns and to ensure an adequate food supply for the birds, the FWS raised rice, barley, and other grains. The agency adopted many of the technologies of modern, industrial agriculture including synthetic herbicides and insecticides such as 2, 4-D and DDT. By the 1960s, the refuges had become largely mirrors of the surrounding irrigated farmlands, the main difference being that the FWS raised grain for waterfowl rather than for market. Refuges could not escape the agricultural settings in which they were embedded. As units within the irrigated countryside, Pacific Flyway refuges were often at the mercy of nearby farmers and federal reclamation agencies. Poor water quality and insufficient supplies of water often hampered FWS efforts to manage refuges. In the late-twentieth century, reduced water supply due to diversions to California municipalities and to sustain endangered fish species affected the amount of water reaching refuges. This dissertation has other goals. First, it critiques the anthropocentrism of most historical geography by focusing on how political, cultural, and ecological factors affected wildlife. Second, it contributes to the literature on the state's role in environmental protection by investigating the overlapping, and often contradictory, spaces within which wildlife managers implemented environmental regulations. Close

• 7. [Image] Programmatic environmental assessment for Klamath Basin Ecosystem Restoration Office Projects, 2000-2010

  	Programmatic Environmental Assessment Summary This Environmental Assessment (EA) provides compliance with the National Environmental Policy Act (NEPA) for restoration actions undertaken by the US Fish ...
  	Citation × Citation Citation Abstract Copy Title: Programmatic environmental assessment for Klamath Basin Ecosystem Restoration Office Projects, 2000-2010 Author: U.S. Fish and Wildlife Service. Klamath Basin Ecosystem Restoration Office. Year: 2000, 2005, 2004 Programmatic Environmental Assessment Summary This Environmental Assessment (EA) provides compliance with the National Environmental Policy Act (NEPA) for restoration actions undertaken by the US Fish & Wildlife Service's Klamath Basin Ecosystem Restoration Office (ERO) in Klamath Falls, Oregon. These restoration activities are needed due to the large-scale loss of wetland and riparian habitat and degraded water quality. The purpose of these restoration efforts is the improvement of conditions of the watershed with specific regard to habitat and water quality, resulting in, among other benefits, improved conditions for the endangered fish species (bull trout and Lost River and shortnose sucker) populations of the basin. The geographic scope of this EA is defined as the upper Klamath River basin, including the entire watershed from Irongate Dam upstream to the headwaters. This EA is intended to provide NEPA compliance for restoration projects conducted between the years 2000 and 2010. The ERO was established in 1993 to sponsor and assist with a variety of restoration activities in the Klamath Basin. The ERO funds and provides technical assistance to restoration projects involving private landholders, concerned groups, and other state, federal, and tribal agencies. Four alternatives are presented in this EA. The proposed alternative (Alternative 1) consists of a comprehensive program of ecosystem restoration, promoting projects in both riparian areas and in upland habitats. This would continue the current program in effect since 1994. NEPA compliance would primarily be carried out via a single, programmatic document saving time and funds. The Fish & Wildlife Service proposes to fund and administer the following projects types: Riparian Projects: (fencing for livestock management; native plant establishment & diversification; non-native plant removal/control; erosion control; contour re-establishment; impoundment removal; wildlife habitat improvements) Wetland Projects: (fencing; wetland restoration and enhancement; wildlife habitat improvements) Upland or Road Projects: (road abandonment, decommissioning, & obliteration; road drainage improvements and storm proofing, re-establishment of historic contours; silvicultural treatments; native plant establishment/diversification; non-native plant removal/control; fencing; landslide treatments; culvert/stream crossing upgrades; erosion control; wildlife habitat improvements). In-stream Projects: (habitat complexity and diversity improvements; hydrologic regime improvements; coarse woody debris supplementation; natural or artificial barrier removal, modification &/or creation; fish screens installation). Alternative 2 would concentrate restoration efforts only on riparian, instream, and wetland areas. Road projects would be conducted only within the riparian corridor, as defined. NEPA compliance would also be conducted programmatically. Alternative 3 would cease all restoration activities conducted and funded by the ERO in the Klamath Basin. This alternative would serve as a benchmark against which the effects of the restoration alternatives discussed above can be compared. Alternative 4, the "No Action" alternative, would continue current management policies with regard to NEPA compliance, providing compliance on a project by project basis requiring independent analysis for each project. The affected environment of the region is described in detail. The environment has been changed significantly since the 1890's due to logging, agriculture and urban development. An extensive system of dams, canals, and drainage structures has resulted in the conversion of approximately 80% of pre-settlement wetlands to agricultural uses. Riparian corridors have been similarly impacted, and upland forests regions have been affected by logging, road construction and other factors. These changes have contributed to problems with the water quality in the region, contributing to the listing of several fish species as threatened or endangered; loss of habitat has affected a large number of other species as well. The environmental effects of each alternative is analyzed. Some short term negative impacts could occur as a result of the projects authorized by both Alternative 1 and Alternative 2, but these would be strongly offset by the expected beneficial results to water quality and habitat conditions. Alternative 1 would be expected to have a greater overall effect on the environment than Alternative 2, since many of the underlying factors with which restoration efforts are concerned originate in upland conditions (i.e. sedimentation and hydrologic functionality). Alternative 3 would result in conditions remaining much as they are currently, although other programs and organizations are making efforts at restoration activities. The environmental impacts of individual projects anticipated under Alternative 4 would be generally the same as for similar projects under Alternative 1. The primary difference between the two alternatives would be the higher efficiency and improved cumulative analysis resulting from a programmatic approach as proposed in Alternative 1. Public participation in the NEPA process has been, and will continue to be, solicited and welcomed. Compliance with state and federal laws and regulations such as the Clean Water Act, National Historic Preservation Act, and the Endangered Species Act, as well as guidelines for contaminant surveys, will be carried out as detailed. While these projects are expected to play an important role in the restoration of the region, none of these alternatives are expected to have a significant impact when compared with the loss of wetland, riparian and upland habitats over the past century, impacts which do occur would be of a cumulatively beneficial nature. Other restoration efforts are being carried out in the area by other governmental and private groups, and it is expected that these combined efforts will achieve important beneficial results for the ecosystem. Title: Programmatic environmental assessment for Klamath Basin Ecosystem Restoration Office Projects, 2000-2010 Author: U.S. Fish and Wildlife Service. Klamath Basin Ecosystem Restoration Office. Year: 2000, 2005, 2004 Programmatic Environmental Assessment Summary This Environmental Assessment (EA) provides compliance with the National Environmental Policy Act (NEPA) for restoration actions undertaken by the US Fish & Wildlife Service's Klamath Basin Ecosystem Restoration Office (ERO) in Klamath Falls, Oregon. These restoration activities are needed due to the large-scale loss of wetland and riparian habitat and degraded water quality. The purpose of these restoration efforts is the improvement of conditions of the watershed with specific regard to habitat and water quality, resulting in, among other benefits, improved conditions for the endangered fish species (bull trout and Lost River and shortnose sucker) populations of the basin. The geographic scope of this EA is defined as the upper Klamath River basin, including the entire watershed from Irongate Dam upstream to the headwaters. This EA is intended to provide NEPA compliance for restoration projects conducted between the years 2000 and 2010. The ERO was established in 1993 to sponsor and assist with a variety of restoration activities in the Klamath Basin. The ERO funds and provides technical assistance to restoration projects involving private landholders, concerned groups, and other state, federal, and tribal agencies. Four alternatives are presented in this EA. The proposed alternative (Alternative 1) consists of a comprehensive program of ecosystem restoration, promoting projects in both riparian areas and in upland habitats. This would continue the current program in effect since 1994. NEPA compliance would primarily be carried out via a single, programmatic document saving time and funds. The Fish & Wildlife Service proposes to fund and administer the following projects types: Riparian Projects: (fencing for livestock management; native plant establishment & diversification; non-native plant removal/control; erosion control; contour re-establishment; impoundment removal; wildlife habitat improvements) Wetland Projects: (fencing; wetland restoration and enhancement; wildlife habitat improvements) Upland or Road Projects: (road abandonment, decommissioning, & obliteration; road drainage improvements and storm proofing, re-establishment of historic contours; silvicultural treatments; native plant establishment/diversification; non-native plant removal/control; fencing; landslide treatments; culvert/stream crossing upgrades; erosion control; wildlife habitat improvements). In-stream Projects: (habitat complexity and diversity improvements; hydrologic regime improvements; coarse woody debris supplementation; natural or artificial barrier removal, modification &/or creation; fish screens installation). Alternative 2 would concentrate restoration efforts only on riparian, instream, and wetland areas. Road projects would be conducted only within the riparian corridor, as defined. NEPA compliance would also be conducted programmatically. Alternative 3 would cease all restoration activities conducted and funded by the ERO in the Klamath Basin. This alternative would serve as a benchmark against which the effects of the restoration alternatives discussed above can be compared. Alternative 4, the "No Action" alternative, would continue current management policies with regard to NEPA compliance, providing compliance on a project by project basis requiring independent analysis for each project. The affected environment of the region is described in detail. The environment has been changed significantly since the 1890's due to logging, agriculture and urban development. An extensive system of dams, canals, and drainage structures has resulted in the conversion of approximately 80% of pre-settlement wetlands to agricultural uses. Riparian corridors have been similarly impacted, and upland forests regions have been affected by logging, road construction and other factors. These changes have contributed to problems with the water quality in the region, contributing to the listing of several fish species as threatened or endangered; loss of habitat has affected a large number of other species as well. The environmental effects of each alternative is analyzed. Some short term negative impacts could occur as a result of the projects authorized by both Alternative 1 and Alternative 2, but these would be strongly offset by the expected beneficial results to water quality and habitat conditions. Alternative 1 would be expected to have a greater overall effect on the environment than Alternative 2, since many of the underlying factors with which restoration efforts are concerned originate in upland conditions (i.e. sedimentation and hydrologic functionality). Alternative 3 would result in conditions remaining much as they are currently, although other programs and organizations are making efforts at restoration activities. The environmental impacts of individual projects anticipated under Alternative 4 would be generally the same as for similar projects under Alternative 1. The primary difference between the two alternatives would be the higher efficiency and improved cumulative analysis resulting from a programmatic approach as proposed in Alternative 1. Public participation in the NEPA process has been, and will continue to be, solicited and welcomed. Compliance with state and federal laws and regulations such as the Clean Water Act, National Historic Preservation Act, and the Endangered Species Act, as well as guidelines for contaminant surveys, will be carried out as detailed. While these projects are expected to play an important role in the restoration of the region, none of these alternatives are expected to have a significant impact when compared with the loss of wetland, riparian and upland habitats over the past century, impacts which do occur would be of a cumulatively beneficial nature. Other restoration efforts are being carried out in the area by other governmental and private groups, and it is expected that these combined efforts will achieve important beneficial results for the ecosystem. Close

• 8. [Image] Draft upper Williamson River Watershed assessment

  	"Prepared for Klamath Basin Ecosystem Foundation, and the Upper Williamson River Catchment Group, in cooperation with the Upper Klamath Basin Working Group, and the Klamath Watershed Council."
  	Citation × Citation Citation Abstract Copy Title: Draft upper Williamson River Watershed assessment Author: David Evans and Associates, Inc. Year: 2004, 2005 "Prepared for Klamath Basin Ecosystem Foundation, and the Upper Williamson River Catchment Group, in cooperation with the Upper Klamath Basin Working Group, and the Klamath Watershed Council." Title: Draft upper Williamson River Watershed assessment Author: David Evans and Associates, Inc. Year: 2004, 2005 "Prepared for Klamath Basin Ecosystem Foundation, and the Upper Williamson River Catchment Group, in cooperation with the Upper Klamath Basin Working Group, and the Klamath Watershed Council." Close

• 9. [Image] Ground water hydrology of four proposed project areas in the Klamath Basin, Oregon

  	"OF-01-01"
  	Citation × Citation Citation Abstract Copy Title: Ground water hydrology of four proposed project areas in the Klamath Basin, Oregon Author: Oregon. Water Resources Dept Year: 2001, 2005 "OF-01-01" Title: Ground water hydrology of four proposed project areas in the Klamath Basin, Oregon Author: Oregon. Water Resources Dept Year: 2001, 2005 "OF-01-01" Close

• 10. [Image] Distribution and biology of suckers in Lower Klamath reservoirs : 1999 final report

  	Abstract The objectives of this two-year study (1998-1999) were to document distribution, abundance, age class structure, recruitment success, and habitat use by all life history stages of shortnose and ...
  	Citation × Citation Citation Abstract Copy Title: Distribution and biology of suckers in Lower Klamath reservoirs : 1999 final report Author: Desjardins, Marc; Markle, Douglas F. Year: 2000, 2005 Abstract The objectives of this two-year study (1998-1999) were to document distribution, abundance, age class structure, recruitment success, and habitat use by all life history stages of shortnose and Lost River suckers in three lower Klamath River hydroelectric reservoirs (J. C. Boyle, Copco, and Iron Gate). Lost River sucker catches were sporadic (only 3 adult individuals total) and the focus of our analyses, therefore, shifted to shortnose suckers. Adult and larval suckers were found in all reservoirs both years. All life history stages (larvae, juveniles and adults) were found in J. C. Boyle during both years and in Copco in 1999. Juvenile suckers were not found in Copco in 1998. The number of adult shortnose suckers was highest in Copco reservoir (n=165), followed by J.C. Boyle (n=50) and Iron Gate (n=22). Larger and older individuals dominated Copco and Iron Gate reservoirs and little size structure was detected. J. C. Boyle tended to have smaller adult shortnose suckers and many size classes were present. Unidentifiable larval suckers were most abundant in Copco reservoir where historic spawning of shortnose suckers has been documented. Larval suckers in Copco and Iron Gate reservoirs were most abundant in mid to late June before quickly disappearing from catches. J. C. Boyle larval suckers peaked in mid July, attained larger sizes, and were caught later in the season. It appeared that recruitment of young-of-the-year suckers only occurred in J. C. Boyle with downstream reservoirs recruiting older individuals, perhaps those that had earlier recruited to J. C. Boyle. Tagging studies could clarify adult recruitment dynamics and an additional study of juvenile recruitment would be needed to confirm these patterns. Predation pressure may be somewhat reduced in J. C. Boyle in comparison to the other reservoirs as its fish community was dominated by native fishes while communities in Copco and Iron Gate reservoirs were dominated by exotic predators. J. C. Boyle also possessed proportionally more littoral habitat, which suggests it may provide a more stable environment for young fishes. However, our sampling was inadequate to demonstrate such relationships due to high variance in larval and juvenile catches and potentially confounding habitat variables. One such variable was water level fluctuations, which could interact with habitat and resource availability in complex ways. For example, water level fluctuations, presumed to have a negative impact, were greatest in J. C. Boyle. Extrapolation from the literature suggests it should have had the poorest habitat for larval and juvenile suckers, but our results indicated J. C. Boyle had the most young suckers. Additional study of the relationships between water level fluctuations, habitat availability, the exotic fish community, and juvenile sucker recruitment would be needed to better understand early life history ecology of endangered lake suckers in these systems. Title: Distribution and biology of suckers in Lower Klamath reservoirs : 1999 final report Author: Desjardins, Marc; Markle, Douglas F. Year: 2000, 2005 Abstract The objectives of this two-year study (1998-1999) were to document distribution, abundance, age class structure, recruitment success, and habitat use by all life history stages of shortnose and Lost River suckers in three lower Klamath River hydroelectric reservoirs (J. C. Boyle, Copco, and Iron Gate). Lost River sucker catches were sporadic (only 3 adult individuals total) and the focus of our analyses, therefore, shifted to shortnose suckers. Adult and larval suckers were found in all reservoirs both years. All life history stages (larvae, juveniles and adults) were found in J. C. Boyle during both years and in Copco in 1999. Juvenile suckers were not found in Copco in 1998. The number of adult shortnose suckers was highest in Copco reservoir (n=165), followed by J.C. Boyle (n=50) and Iron Gate (n=22). Larger and older individuals dominated Copco and Iron Gate reservoirs and little size structure was detected. J. C. Boyle tended to have smaller adult shortnose suckers and many size classes were present. Unidentifiable larval suckers were most abundant in Copco reservoir where historic spawning of shortnose suckers has been documented. Larval suckers in Copco and Iron Gate reservoirs were most abundant in mid to late June before quickly disappearing from catches. J. C. Boyle larval suckers peaked in mid July, attained larger sizes, and were caught later in the season. It appeared that recruitment of young-of-the-year suckers only occurred in J. C. Boyle with downstream reservoirs recruiting older individuals, perhaps those that had earlier recruited to J. C. Boyle. Tagging studies could clarify adult recruitment dynamics and an additional study of juvenile recruitment would be needed to confirm these patterns. Predation pressure may be somewhat reduced in J. C. Boyle in comparison to the other reservoirs as its fish community was dominated by native fishes while communities in Copco and Iron Gate reservoirs were dominated by exotic predators. J. C. Boyle also possessed proportionally more littoral habitat, which suggests it may provide a more stable environment for young fishes. However, our sampling was inadequate to demonstrate such relationships due to high variance in larval and juvenile catches and potentially confounding habitat variables. One such variable was water level fluctuations, which could interact with habitat and resource availability in complex ways. For example, water level fluctuations, presumed to have a negative impact, were greatest in J. C. Boyle. Extrapolation from the literature suggests it should have had the poorest habitat for larval and juvenile suckers, but our results indicated J. C. Boyle had the most young suckers. Additional study of the relationships between water level fluctuations, habitat availability, the exotic fish community, and juvenile sucker recruitment would be needed to better understand early life history ecology of endangered lake suckers in these systems. Close

• 11. [Image] Natural history and ecology of larval Lost River suckers and larval shortnose suckers in the Williamson River-Upper Klamath Lake System

  	We monitored larval Lost River and shortnose suckers from natal beds in the Williamson and Sprague rivers to nursery grounds in Upper Klamath Lake. Downstream movements occurred at night, in the middle ...
  	Citation × Citation Citation Abstract Copy Title: Natural history and ecology of larval Lost River suckers and larval shortnose suckers in the Williamson River-Upper Klamath Lake System Author: Cooperman, Michael S. Year: 2004, 2005 We monitored larval Lost River and shortnose suckers from natal beds in the Williamson and Sprague rivers to nursery grounds in Upper Klamath Lake. Downstream movements occurred at night, in the middle of the channel, and on the falling limb of the hydrograph. Ages, sizes, and developmental stages of larvae from spawning beds and the river mouth were similar, while larvae collected contemporaneously from the lake tended to be larger and better fed. Our results indicate in-river rearing was rare, that a rapid outmigration to the lake was favorable for larval survival, and that modification of the lower Williamson River does not appear to have prohibited rapid entry or preclude access to Upper Klamath Lake. Within the Williamson River and Upper Klamath Lake, emergent macrophytes supported significantly higher abundance, larger mean sizes, and better fed larvae than submerged macrophytes, woody vegetation, or open water areas. Analysis of seven years of larval sucker production and survival corroborated the habitat analysis by identifying a positive relationship with emergent macrophyte availability as well as a positive relationship with air temperature and a negative relationship with high wind. These findings illustrate the importance of fast growth, appropriate habitat and calm hydrological conditions for larvae, and are highly consistent with other larval fish studies. Title: Natural history and ecology of larval Lost River suckers and larval shortnose suckers in the Williamson River-Upper Klamath Lake System Author: Cooperman, Michael S. Year: 2004, 2005 We monitored larval Lost River and shortnose suckers from natal beds in the Williamson and Sprague rivers to nursery grounds in Upper Klamath Lake. Downstream movements occurred at night, in the middle of the channel, and on the falling limb of the hydrograph. Ages, sizes, and developmental stages of larvae from spawning beds and the river mouth were similar, while larvae collected contemporaneously from the lake tended to be larger and better fed. Our results indicate in-river rearing was rare, that a rapid outmigration to the lake was favorable for larval survival, and that modification of the lower Williamson River does not appear to have prohibited rapid entry or preclude access to Upper Klamath Lake. Within the Williamson River and Upper Klamath Lake, emergent macrophytes supported significantly higher abundance, larger mean sizes, and better fed larvae than submerged macrophytes, woody vegetation, or open water areas. Analysis of seven years of larval sucker production and survival corroborated the habitat analysis by identifying a positive relationship with emergent macrophyte availability as well as a positive relationship with air temperature and a negative relationship with high wind. These findings illustrate the importance of fast growth, appropriate habitat and calm hydrological conditions for larvae, and are highly consistent with other larval fish studies. Close

• 12. [Image] Geologic and hydrologic characterization and evaluation of the Basin and Range Province relative to the disposal of high-level radioactive waste [part 1 introduction and guidelines]

  	SUMMARY The U.S. Geological Survey's program for geologic and hydrologic evaluation of physiographic provinces to identify areas potentially suitable for locating repository sites for disposal of high-level ...
  	Citation × Citation Citation Abstract Copy Title: Geologic and hydrologic characterization and evaluation of the Basin and Range Province relative to the disposal of high-level radioactive waste [part 1 introduction and guidelines] Author: Bedinger, M. S.; Sargent, Kenneth A.; Reed, J. E. Year: 2008, 2005 SUMMARY The U.S. Geological Survey's program for geologic and hydrologic evaluation of physiographic provinces to identify areas potentially suitable for locating repository sites for disposal of high-level nuclear wastes was announced to the Governors of the eight States in the Basin and Range Province on May 5, 1981. Representatives of Arizona, California, Idaho, New Mexico, Nevada, Oregon, Texas, and Utah, were invited to cooperate with the Federal Government in the evaluation process. Each Governor was requested to nominate an Earth scientist to represent the State in a province working group composed of State and U.S. Geological Survey representatives. This report, Part I of a three-part report, provides the background, introduction and scope of the study. This part also includes a discussion of geologic and hydrologic guidelines that will be used in the evaluation process and illustrates geohydro-logic environments and the effect of individual factors in providing multiple natural barriers to radionuclide migration. Part II is a reconnaissance characterization of the geologic and hydrologic factors to be used in the initial screening of the Basin and Range Province. Part III will be the initial evaluation of the Province and will identify regions that appear suitable for further study. The plan for study of the Province includes a stepwise screening process by which successively smaller land units are considered in increasing detail. Each step involves characterization of the geology and hydrology and selection of subunits for more intensive characterization. Selection of subunits for further study is by evaluation of geologic and hydrologic conditions following a set of guidelines. By representation on the Province Working Group, the States participate in a consultation and review role in: (1) Establishing geologic and hydrologic guidelines, and (2) characterizing and evaluating the Province. The States also participate in compilation of geologic and hydrologic data used in characterizing the Province. The current (1983) needs for a high-level radioactive waste repository include: (1) Disposal in a mined repository; (2) re- trievability of the waste for as much as 50 years; and (3) confidence of isolation of the waste from the accessible environment. Isolation of the waste needs to be assured using geologic and hydrologic conditions that: (1) Minimize risk of inadvertent future intrusions by man; (2) minimize the possibility of disturbance by processes that would expose the waste or increase its mobility; and (3) provide a system of natural barriers to the migration of waste by ground water. The guidelines adopted by the Province Working Group are designed to provide a standard with which these conditions can be compared. The guidelines can be grouped into four principal categories: (1) Potential host media, (2) ground-water conditions, (3) tectonic conditions, and (4) occurrence of natural resources. Ideally the host medium constitutes the first natural barrier to migration of radionculides. The host medium ideally should be a rock type that prevents or retards dissolution and transport of radionuclides. Rocks in both the saturated and unsaturated zones may have desirable characteristics for host media. Rocks?other than the host?in the ground-water flow path from the repository ideally should be major barriers to radionuclide migration. Confining beds of low permeability might be present to retard the rate of flow between more permeable beds. Additionally, sorption of radionuclides by materials such as clays and zeolites in the flow path can further retard the flow of radionuclides by several orders of magnitude. Tectonic conditions in an area should not present a probable cause for exhumation or increased mobility of radioactive waste. Natural resources are a factor for consideration because of the problem of future human intrusion and exposure to radioactivity in the quest for minerals, oil, gas, water, and geothermal resources. The ultimate evaluation of the suitability of a geohydrologic environment for developing a mined repository needs to assess all geologic and hydrologic characteristics and their interaction in providing confidence that a geohydrologic environment will effectively isolate radionuclides from human access. Several hypothetical settings with typical geohydrologic conditions in the Basin and Range Province are used to illustrate the effect of multiple barriers in the isolation of radionuclides. Title: Geologic and hydrologic characterization and evaluation of the Basin and Range Province relative to the disposal of high-level radioactive waste [part 1 introduction and guidelines] Author: Bedinger, M. S.; Sargent, Kenneth A.; Reed, J. E. Year: 2008, 2005 SUMMARY The U.S. Geological Survey's program for geologic and hydrologic evaluation of physiographic provinces to identify areas potentially suitable for locating repository sites for disposal of high-level nuclear wastes was announced to the Governors of the eight States in the Basin and Range Province on May 5, 1981. Representatives of Arizona, California, Idaho, New Mexico, Nevada, Oregon, Texas, and Utah, were invited to cooperate with the Federal Government in the evaluation process. Each Governor was requested to nominate an Earth scientist to represent the State in a province working group composed of State and U.S. Geological Survey representatives. This report, Part I of a three-part report, provides the background, introduction and scope of the study. This part also includes a discussion of geologic and hydrologic guidelines that will be used in the evaluation process and illustrates geohydro-logic environments and the effect of individual factors in providing multiple natural barriers to radionuclide migration. Part II is a reconnaissance characterization of the geologic and hydrologic factors to be used in the initial screening of the Basin and Range Province. Part III will be the initial evaluation of the Province and will identify regions that appear suitable for further study. The plan for study of the Province includes a stepwise screening process by which successively smaller land units are considered in increasing detail. Each step involves characterization of the geology and hydrology and selection of subunits for more intensive characterization. Selection of subunits for further study is by evaluation of geologic and hydrologic conditions following a set of guidelines. By representation on the Province Working Group, the States participate in a consultation and review role in: (1) Establishing geologic and hydrologic guidelines, and (2) characterizing and evaluating the Province. The States also participate in compilation of geologic and hydrologic data used in characterizing the Province. The current (1983) needs for a high-level radioactive waste repository include: (1) Disposal in a mined repository; (2) re- trievability of the waste for as much as 50 years; and (3) confidence of isolation of the waste from the accessible environment. Isolation of the waste needs to be assured using geologic and hydrologic conditions that: (1) Minimize risk of inadvertent future intrusions by man; (2) minimize the possibility of disturbance by processes that would expose the waste or increase its mobility; and (3) provide a system of natural barriers to the migration of waste by ground water. The guidelines adopted by the Province Working Group are designed to provide a standard with which these conditions can be compared. The guidelines can be grouped into four principal categories: (1) Potential host media, (2) ground-water conditions, (3) tectonic conditions, and (4) occurrence of natural resources. Ideally the host medium constitutes the first natural barrier to migration of radionculides. The host medium ideally should be a rock type that prevents or retards dissolution and transport of radionuclides. Rocks in both the saturated and unsaturated zones may have desirable characteristics for host media. Rocks?other than the host?in the ground-water flow path from the repository ideally should be major barriers to radionuclide migration. Confining beds of low permeability might be present to retard the rate of flow between more permeable beds. Additionally, sorption of radionuclides by materials such as clays and zeolites in the flow path can further retard the flow of radionuclides by several orders of magnitude. Tectonic conditions in an area should not present a probable cause for exhumation or increased mobility of radioactive waste. Natural resources are a factor for consideration because of the problem of future human intrusion and exposure to radioactivity in the quest for minerals, oil, gas, water, and geothermal resources. The ultimate evaluation of the suitability of a geohydrologic environment for developing a mined repository needs to assess all geologic and hydrologic characteristics and their interaction in providing confidence that a geohydrologic environment will effectively isolate radionuclides from human access. Several hypothetical settings with typical geohydrologic conditions in the Basin and Range Province are used to illustrate the effect of multiple barriers in the isolation of radionuclides. Close

• 13. [Image] Geologic and hydrologic characterization and evaluation of the Basin and Range Province relative to the disposal of high-level radioactive waste [part 2 geologic and hydrologic characterization ]

  	SUMMARY The geology and hydrology of the Basin and Range Province of the western conterminous United States are characterized in a series of data sets depicted in maps compiled for evaluation of prospective ...
  	Citation × Citation Citation Abstract Copy Title: Geologic and hydrologic characterization and evaluation of the Basin and Range Province relative to the disposal of high-level radioactive waste [part 2 geologic and hydrologic characterization ] Author: Bedinger, M. S.; Sargent, Kenneth A.; Reed, J. E. Year: 2008, 2005 SUMMARY The geology and hydrology of the Basin and Range Province of the western conterminous United States are characterized in a series of data sets depicted in maps compiled for evaluation of prospective areas for further study of geohydrologic environments for isolation of high-level radioactive waste. The data sets include: (1) Average precipitation and evaporation; (2) surface distribution of selected rock types; (3) tectonic conditions; and (4) surface- and ground-water hydrology and Pleistocene lakes and marshes. Rocks mapped for consideration as potential host media for the isolation of high-level radioactive waste are widespread and include argillaceous rocks, granitic rocks, tuffaceous rocks, mafic extrusive rocks, evaporites, and laharic breccias. The unsaturated zone, where probably as thick as 150 meters (500 feet), was mapped for consideration as an environment for isolation of high-level waste. Unsaturated rocks of various lithologic types are widespread in the Province. Tectonic stability in the Quaternary Period is considered the key to assessing the probability of future tectonism with regard to high-level radioactive waste disposal. Tectonic conditions are characterized on the basis of the seismic record, heat-flow measurements, the occurrence of Quaternary faults, vertical crustal movement, and volcanic features. Tectonic activity, as indicated by seismicity, is greatest in areas bordering the western margin of the Province in Nevada and southern California, the eastern margin of the Province bordering the Wasatch Mountains in Utah and in parts of the Rio Grande valley. Late Cenozoic volcanic activity is widespread, being greatest bordering the Sierra Nevada in California and Oregon, and bordering the Wasatch Mountains in southern Utah and Idaho. The arid to semiarid climate of the Province results in few perennial streams and lakes. A large part of the surface drainage is interior and the many closed basins commonly are occupied by playas or dry lake beds. The Province is divided into ground-water flow units defined on the basis of ground-water divides, ground-water flow lines, and surface streams that receive ground-water discharge. Ground water contains less than 500 milligrams per liter of dissolved solids throughout most of the Province. Ground water is more mineralized in areas underlain by evaporitic rocks, overlain by playas, and near saline lakes. Ground water is of the calcium, magnesium, or sodium bicarbonate type in the areas where dissolved-solids concentrations are less than 500 milligrams per liter, and of the calcium, magnesium, or sodium sulfate or chloride type where dissolved-solids concentrations are greater than 500 milligrams per liter. Geologic and hydrologic evidence is found for about 100 lakes and marshes that existed during the Pleistocene Epoch. The possibility of a recurrence of pluvial conditions, such as existed in the Pleistocene, is of concern in repository siting because of possible changes in hydrologic conditions. The Pleistocene lakes and marshes provide clues to the hydrology during pluvial climates. Title: Geologic and hydrologic characterization and evaluation of the Basin and Range Province relative to the disposal of high-level radioactive waste [part 2 geologic and hydrologic characterization ] Author: Bedinger, M. S.; Sargent, Kenneth A.; Reed, J. E. Year: 2008, 2005 SUMMARY The geology and hydrology of the Basin and Range Province of the western conterminous United States are characterized in a series of data sets depicted in maps compiled for evaluation of prospective areas for further study of geohydrologic environments for isolation of high-level radioactive waste. The data sets include: (1) Average precipitation and evaporation; (2) surface distribution of selected rock types; (3) tectonic conditions; and (4) surface- and ground-water hydrology and Pleistocene lakes and marshes. Rocks mapped for consideration as potential host media for the isolation of high-level radioactive waste are widespread and include argillaceous rocks, granitic rocks, tuffaceous rocks, mafic extrusive rocks, evaporites, and laharic breccias. The unsaturated zone, where probably as thick as 150 meters (500 feet), was mapped for consideration as an environment for isolation of high-level waste. Unsaturated rocks of various lithologic types are widespread in the Province. Tectonic stability in the Quaternary Period is considered the key to assessing the probability of future tectonism with regard to high-level radioactive waste disposal. Tectonic conditions are characterized on the basis of the seismic record, heat-flow measurements, the occurrence of Quaternary faults, vertical crustal movement, and volcanic features. Tectonic activity, as indicated by seismicity, is greatest in areas bordering the western margin of the Province in Nevada and southern California, the eastern margin of the Province bordering the Wasatch Mountains in Utah and in parts of the Rio Grande valley. Late Cenozoic volcanic activity is widespread, being greatest bordering the Sierra Nevada in California and Oregon, and bordering the Wasatch Mountains in southern Utah and Idaho. The arid to semiarid climate of the Province results in few perennial streams and lakes. A large part of the surface drainage is interior and the many closed basins commonly are occupied by playas or dry lake beds. The Province is divided into ground-water flow units defined on the basis of ground-water divides, ground-water flow lines, and surface streams that receive ground-water discharge. Ground water contains less than 500 milligrams per liter of dissolved solids throughout most of the Province. Ground water is more mineralized in areas underlain by evaporitic rocks, overlain by playas, and near saline lakes. Ground water is of the calcium, magnesium, or sodium bicarbonate type in the areas where dissolved-solids concentrations are less than 500 milligrams per liter, and of the calcium, magnesium, or sodium sulfate or chloride type where dissolved-solids concentrations are greater than 500 milligrams per liter. Geologic and hydrologic evidence is found for about 100 lakes and marshes that existed during the Pleistocene Epoch. The possibility of a recurrence of pluvial conditions, such as existed in the Pleistocene, is of concern in repository siting because of possible changes in hydrologic conditions. The Pleistocene lakes and marshes provide clues to the hydrology during pluvial climates. Close

• 14. [Image] Geologic and hydrologic characterization and evaluation of the Basin and Range Province relative to the disposal of high-level radioactive waste [part 3 geologic and hydrologic evaluation]

  	SUMMARY This report describes the first phase in evaluating the geology and hydrology of the Basin and Range Province for potential suitability of geohydrologic environments for isolation of high-level ...
  	Citation × Citation Citation Abstract Copy Title: Geologic and hydrologic characterization and evaluation of the Basin and Range Province relative to the disposal of high-level radioactive waste [part 3 geologic and hydrologic evaluation] Author: Bedinger, M. S.; Sargent, Kenneth A.; Reed, J. E. Year: 2008, 2005 SUMMARY This report describes the first phase in evaluating the geology and hydrology of the Basin and Range Province for potential suitability of geohydrologic environments for isolation of high-level radioactive waste. The evaluation of the Province applies the guidelines, discussed in Part I (Bedinger, Sargent, and Reed, 1983) of this report to the geologic and hydrologic information compiled for the Province in Part II (Sargent and Bedinger, 1983). The geologic and hydrologic factors considered in the Province evaluation include distribution of potential host rocks, tectonic conditions and data on ground-water hydrology. Potential host media considered include argillaceous rocks, tuff, basaltic rocks, granitic rocks, evaporites, and the unsaturated zone. The tectonic factors considered are Quaternary faults, late Cenozoic volcanics, seismic activity, heat flow, and late Cenozoic rates of vertical uplift. Hydrologic conditions considered include length of flow path from potential host rocks to discharge areas, interbasin and geothermal flow systems and thick unsaturated sections as potential host media. The Basin and Range Province was divided into 12 subprovinces; each subprovince is evaluated separately and prospective areas for further study are identified. About one-half of the Province appears to have combinations of potential host rocks, tectonic conditions, and ground-water hydrology that merit consideration for further study. The prospective areas for further study in each subprovince are summarized in a brief list of the potentially favorable factors and the issues of concern. Data compiled for the entire Province do not permit a complete evaluation of the f avorability for high-level waste isolation. The evaluations here are intended to identify broad regions that contain potential geohydrologic environments containing multiple natural barriers to radionu-clide migration. Title: Geologic and hydrologic characterization and evaluation of the Basin and Range Province relative to the disposal of high-level radioactive waste [part 3 geologic and hydrologic evaluation] Author: Bedinger, M. S.; Sargent, Kenneth A.; Reed, J. E. Year: 2008, 2005 SUMMARY This report describes the first phase in evaluating the geology and hydrology of the Basin and Range Province for potential suitability of geohydrologic environments for isolation of high-level radioactive waste. The evaluation of the Province applies the guidelines, discussed in Part I (Bedinger, Sargent, and Reed, 1983) of this report to the geologic and hydrologic information compiled for the Province in Part II (Sargent and Bedinger, 1983). The geologic and hydrologic factors considered in the Province evaluation include distribution of potential host rocks, tectonic conditions and data on ground-water hydrology. Potential host media considered include argillaceous rocks, tuff, basaltic rocks, granitic rocks, evaporites, and the unsaturated zone. The tectonic factors considered are Quaternary faults, late Cenozoic volcanics, seismic activity, heat flow, and late Cenozoic rates of vertical uplift. Hydrologic conditions considered include length of flow path from potential host rocks to discharge areas, interbasin and geothermal flow systems and thick unsaturated sections as potential host media. The Basin and Range Province was divided into 12 subprovinces; each subprovince is evaluated separately and prospective areas for further study are identified. About one-half of the Province appears to have combinations of potential host rocks, tectonic conditions, and ground-water hydrology that merit consideration for further study. The prospective areas for further study in each subprovince are summarized in a brief list of the potentially favorable factors and the issues of concern. Data compiled for the entire Province do not permit a complete evaluation of the f avorability for high-level waste isolation. The evaluations here are intended to identify broad regions that contain potential geohydrologic environments containing multiple natural barriers to radionu-clide migration. Close

• 15. [Image] Historical landscape overview of the upper Klamath River Canyon of Oregon and California

  	"Submitted to Klamath Falls Resource Area, Bureau of Land Management, Lakeview District, Klamath Falls, Oregon." ; "Contract no.: HAP032021."; Includes bibliographical references (p. 178-200)
  	Citation × Citation Citation Abstract Copy Title: Historical landscape overview of the upper Klamath River Canyon of Oregon and California Author: Beckham, Stephen Dow Year: 2006, 2008, 2007 "Submitted to Klamath Falls Resource Area, Bureau of Land Management, Lakeview District, Klamath Falls, Oregon." ; "Contract no.: HAP032021."; Includes bibliographical references (p. 178-200) Title: Historical landscape overview of the upper Klamath River Canyon of Oregon and California Author: Beckham, Stephen Dow Year: 2006, 2008, 2007 "Submitted to Klamath Falls Resource Area, Bureau of Land Management, Lakeview District, Klamath Falls, Oregon." ; "Contract no.: HAP032021."; Includes bibliographical references (p. 178-200) Close

• 16. [Image] A geologic and hydrologic reconnaissance of Lava Beds National Monument and vicinity, California

  	A GEOLOGIC AND HYDROLOGIC RECONNAISSANCE OF LAVA BEDS NATIONAL MONUMENT AND VICINITY, CALIFORNIA By William R. Hotchkiss ABSTRACT Lava Beds National Monument is on the Modoc Plateau in Modoc and ...
  	Citation × Citation Citation Abstract Copy Title: A geologic and hydrologic reconnaissance of Lava Beds National Monument and vicinity, California Author: Hotchkiss, W. R Year: 1968, 2008, 2005 A GEOLOGIC AND HYDROLOGIC RECONNAISSANCE OF LAVA BEDS NATIONAL MONUMENT AND VICINITY, CALIFORNIA By William R. Hotchkiss ABSTRACT Lava Beds National Monument is on the Modoc Plateau in Modoc and Siskiyou Counties. The principal geologic units in the vicinity are volcanic rocks,, which in places are highly permeable, and poorly permeable lake sedimentary deposits, all probably post-Oligocene in age. Yields and specific capacities of wells in the unconfined water body within volcanic rocks and lake deposits range widely, but in general are low in the lake deposits and higher in the volcanic rocks. A confined water body, occurring in volcanic rocks underlying the lake deposits yields large quantities of water to three wells in the study area. Dissolved-solids content of ground water generally increases in proportion to the thickness of lake deposits penetrated and to proximity of the lake deposits. Water from wells drilled in the volcanic rocks several miles from the lake deposits, and from wells penetrating the confined water body in volcanic rocks underlying the lake deposits contains small to moderate quantities of dissolved solids. Ground-water supplies can be developed almost anywhere in the study area by drilling wells to depths below the water table. In addition, there is a reasonable possibility of developing wells in a confined water body underlying the water-table system- Title: A geologic and hydrologic reconnaissance of Lava Beds National Monument and vicinity, California Author: Hotchkiss, W. R Year: 1968, 2008, 2005 A GEOLOGIC AND HYDROLOGIC RECONNAISSANCE OF LAVA BEDS NATIONAL MONUMENT AND VICINITY, CALIFORNIA By William R. Hotchkiss ABSTRACT Lava Beds National Monument is on the Modoc Plateau in Modoc and Siskiyou Counties. The principal geologic units in the vicinity are volcanic rocks,, which in places are highly permeable, and poorly permeable lake sedimentary deposits, all probably post-Oligocene in age. Yields and specific capacities of wells in the unconfined water body within volcanic rocks and lake deposits range widely, but in general are low in the lake deposits and higher in the volcanic rocks. A confined water body, occurring in volcanic rocks underlying the lake deposits yields large quantities of water to three wells in the study area. Dissolved-solids content of ground water generally increases in proportion to the thickness of lake deposits penetrated and to proximity of the lake deposits. Water from wells drilled in the volcanic rocks several miles from the lake deposits, and from wells penetrating the confined water body in volcanic rocks underlying the lake deposits contains small to moderate quantities of dissolved solids. Ground-water supplies can be developed almost anywhere in the study area by drilling wells to depths below the water table. In addition, there is a reasonable possibility of developing wells in a confined water body underlying the water-table system- Close

• 17. [Image] Lakeview proposed resource management plan and final environmental impact statement [volume 1]

  	4 v.; maps (some col.); "August 2002"; "January 2003" -- cover
  	Citation × Citation Citation Abstract Copy Title: Lakeview proposed resource management plan and final environmental impact statement [volume 1] Author: U.S. Department of the Interior. Bureau of Land Management; Lakeview Resource Area Office. Lakeview District Year: 2002, 2006, 2005 4 v.; maps (some col.); "August 2002"; "January 2003" -- cover Title: Lakeview proposed resource management plan and final environmental impact statement [volume 1] Author: U.S. Department of the Interior. Bureau of Land Management; Lakeview Resource Area Office. Lakeview District Year: 2002, 2006, 2005 4 v.; maps (some col.); "August 2002"; "January 2003" -- cover Close

• 18. [Image] Macroecology, paleoecology, and ecological integrity of terrestrial species and communities of the interior Columbia River basin and northern portions of the Klamath and Great Basins

  	This report presents information on biogeography and broad-scale ecology (macroecology) of selected fungi, lichens, bryophytes, vascular plants, invertebrates, and vertebrates of the interior Columbia ...
  	Citation × Citation Citation Abstract Copy Title: Macroecology, paleoecology, and ecological integrity of terrestrial species and communities of the interior Columbia River basin and northern portions of the Klamath and Great Basins Author: U.S. Department of Agriculture. Forest Service. Pacific Northwest Research Station; U.S.Department of the Interior. Bureau of Land Management. Year: 1998, 2006, 2005 This report presents information on biogeography and broad-scale ecology (macroecology) of selected fungi, lichens, bryophytes, vascular plants, invertebrates, and vertebrates of the interior Columbia River basin and adjacent areas. Rare plants include many endemics associated with local conditions. Potential plant and invertebrate bioindicators are identified. Species ecological functions differ among communities and variously affect ecosystem diversity and productivity. Species of alpine and subalpine communities are identified that may be at risk from climate change. Maps of terrestrial ecological integrity are presented. Keywords: Macroecology, paleoecology, ecological integrity, terrestrial communities, ecosystems, wildlife, fungi, lichens, bryophytes, vascular plants, invertebrates, arthropods, mollusks, amphibians, reptiles, birds, mammals, endemism, interior Columbia River basin, Klamath Basin, Great Basin. Title: Macroecology, paleoecology, and ecological integrity of terrestrial species and communities of the interior Columbia River basin and northern portions of the Klamath and Great Basins Author: U.S. Department of Agriculture. Forest Service. Pacific Northwest Research Station; U.S.Department of the Interior. Bureau of Land Management. Year: 1998, 2006, 2005 This report presents information on biogeography and broad-scale ecology (macroecology) of selected fungi, lichens, bryophytes, vascular plants, invertebrates, and vertebrates of the interior Columbia River basin and adjacent areas. Rare plants include many endemics associated with local conditions. Potential plant and invertebrate bioindicators are identified. Species ecological functions differ among communities and variously affect ecosystem diversity and productivity. Species of alpine and subalpine communities are identified that may be at risk from climate change. Maps of terrestrial ecological integrity are presented. Keywords: Macroecology, paleoecology, ecological integrity, terrestrial communities, ecosystems, wildlife, fungi, lichens, bryophytes, vascular plants, invertebrates, arthropods, mollusks, amphibians, reptiles, birds, mammals, endemism, interior Columbia River basin, Klamath Basin, Great Basin. Close

• 19. [Image] Genetic analysis of Klamath River green sturgeon (acipensar [i.e. acipenser] medirostris)

  	Abstract The utility of using isozyme analysis to study the stock structure among West Coast populations of green sturgeon (Acipenser medirostris) was assessed. Isozyme analysis was not determined ...
  	Citation × Citation Citation Abstract Copy Title: Genetic analysis of Klamath River green sturgeon (acipensar [i.e. acipenser] medirostris) Author: Mulligan, Helen Year: 2000, 2005 Abstract The utility of using isozyme analysis to study the stock structure among West Coast populations of green sturgeon (Acipenser medirostris) was assessed. Isozyme analysis was not determined to be an adequate method for assessing stock structure in green sturgeon for the following reasons: 1) the complex nature of isozyme expression 2) the relatively poor resolution of enzyme systems for our samples 3) the invasive nature of collecting tissue samples for isozyme analysis, which necessitates sacrificing the fish, precludes collection of samples from some rivers. The stomach contents of 23 green sturgeon collected from fish harvested in the Klamath River were analyzed. Only four stomachs contained identifiable food items, with the others containing food far too digested for identification, gravel, or no contents. Two stomachs contained the small gastropod, Olivellapyna, one stomach contained the carapace remains of a female Dungeness crab, Cancer magister, and one stomach contained the posterior portions of three ammocoetes, Lampetra tridentata. Preliminary analysis was conducted using mtDNA to assess the potential of using this technique for assessing the stock structure of green sturgeon. Although the Klamath River Fishery Restoration Program did not fund this analysis, the results are presented because this work was designed to yield complementary information to the isozyme study. No diagnostic differences were detected between samples collected from the Klamath River and the Columbia River estuary using Restriction Fragment Length Polymorphism analysis. Study results indicated that microsateliite DNA analyst might be the most appropriate current genetic technique for assessing the population structure of green sturgeon. Title: Genetic analysis of Klamath River green sturgeon (acipensar [i.e. acipenser] medirostris) Author: Mulligan, Helen Year: 2000, 2005 Abstract The utility of using isozyme analysis to study the stock structure among West Coast populations of green sturgeon (Acipenser medirostris) was assessed. Isozyme analysis was not determined to be an adequate method for assessing stock structure in green sturgeon for the following reasons: 1) the complex nature of isozyme expression 2) the relatively poor resolution of enzyme systems for our samples 3) the invasive nature of collecting tissue samples for isozyme analysis, which necessitates sacrificing the fish, precludes collection of samples from some rivers. The stomach contents of 23 green sturgeon collected from fish harvested in the Klamath River were analyzed. Only four stomachs contained identifiable food items, with the others containing food far too digested for identification, gravel, or no contents. Two stomachs contained the small gastropod, Olivellapyna, one stomach contained the carapace remains of a female Dungeness crab, Cancer magister, and one stomach contained the posterior portions of three ammocoetes, Lampetra tridentata. Preliminary analysis was conducted using mtDNA to assess the potential of using this technique for assessing the stock structure of green sturgeon. Although the Klamath River Fishery Restoration Program did not fund this analysis, the results are presented because this work was designed to yield complementary information to the isozyme study. No diagnostic differences were detected between samples collected from the Klamath River and the Columbia River estuary using Restriction Fragment Length Polymorphism analysis. Study results indicated that microsateliite DNA analyst might be the most appropriate current genetic technique for assessing the population structure of green sturgeon. Close

• 20. [Image] Implementation of the Endangered Species Act of 1973 (Report to the House Committee on Resources)

  	I. Executive Summary There is increasing recognition from most quarters that the Endangered Species Act (ESA) needs to be improved. Exactly what those improvements should be is less uniform. ...
  	Citation × Citation Citation Abstract Copy Title: Implementation of the Endangered Species Act of 1973 (Report to the House Committee on Resources) Author: United States. Congress. House. Committee on Resources Year: 2005, 2007 I. Executive Summary There is increasing recognition from most quarters that the Endangered Species Act (ESA) needs to be improved. Exactly what those improvements should be is less uniform. This report examines the implementation of selected aspects of the endangered species program relying predominately on information provided by the primary implementing agencies, the United States Fish and Wildlife Service (FWS) and National Marine Fisheries Service (NMFS) and offers some recommendations for possible improvements to the program. Debate over the ESA has traditionally been highly polarized. For example, compensating landowners for takings or reductions in property value has been opposed by some who argue updating the law to address this is not necessary. While consensus on other issues such as the need for increasing conservation incentives and the role states play in endangered species conservation has begun to emerge, one of the most debated aspects of ESA implementation continues to be whether the ESA is effectively conserving endangered and threatened species. While there have been significant strides in conserving individual species such as the whooping crane, red-cockaded woodpecker and gray wolf, few species have been delisted (removed from the endangered list) or downlisted (changed in status from endangered to threatened) because of successful ESA conservation efforts. Some argue that the number of recovered species is an unfair measure, asserting that the three decades the ESA has been in existence is an insufficient amount of time for the lengthy process of species recovery and point to listed species that have not gone extinct as evidence the ESA 'saves' species. From the opposing perspective, while recovery to the point of delisting may require a substantial amount of time for many species, after three decades more progress should be demonstrable through species that have recovered and been delisted. Even if a species has increased in numbers or distribution or the threats facing the species have been reduced, if it has not been delisted on the basis of recovery, the ESA's prohibitions and regulations remain applicable and the ESA should not be a 'one way street.' Of 40 total species removed from the list, 10 domestic species were delisted because of "recovery". Of 33 reclassified species, 10 domestic downlistings (a change from endangered to threatened status) reflected a reduced threat assessment which also allowed more flexibility in management. The FWS's most recent report to Congress (Fiscal years 2001-2002) shows that 77 percent of listed species fall in the 0 to 25 percent recovery achieved bracket and 2 percent fall in the 76 to 100 percent recovery achieved bracket. 39 percent of the FWS managed species are of uncertain status. Of those with an assessed trend, at one end of the spectrum are 3 percent possibly extinct, 1 percent occurring only in captivity and 21 percent declining and at the other end are 30 percent stable and 6 percent improving. These assessments however are subjective. Additionally, the assessment that a species is improving or stable may reflect, for example, a reduction in perceived threats or corrections to inaccurate threat assessments that stemmed from erroneous data rather than actual changes in species' trends that are demonstrated by improved numbers, distribution or other such measurements. Consequently, a meaningful assessment of conservation trends under the ESA using these data is not possible. The data used to list a number of species has been subsequently determined to be erroneous and species that likely do not merit classification as endangered or threatened remain listed. This can consume resources that could be directed to species that do merit listing. The assignment of recovery priorities appears highly skewed and the recovery priority for some species seems questionable. A meaningful distinction between endangered status and threatened status has been blurred as has been the framework for the mechanism of critical habitat. Expenditure reporting has improved but presents an incomplete picture of financial resources dedicated to endangered species. Workloads for litigation regarding activities such as consultation and listing under the ESA's complex structure compete for resources that could otherwise be directed at recovery efforts. The demands associated with ESA Section 4 determinations in combination with the pace of species listings and delistings, the number of possible future additions to the list and the economic impact of listings likely indicate that the current program is not sustainable. Title: Implementation of the Endangered Species Act of 1973 (Report to the House Committee on Resources) Author: United States. Congress. House. Committee on Resources Year: 2005, 2007 I. Executive Summary There is increasing recognition from most quarters that the Endangered Species Act (ESA) needs to be improved. Exactly what those improvements should be is less uniform. This report examines the implementation of selected aspects of the endangered species program relying predominately on information provided by the primary implementing agencies, the United States Fish and Wildlife Service (FWS) and National Marine Fisheries Service (NMFS) and offers some recommendations for possible improvements to the program. Debate over the ESA has traditionally been highly polarized. For example, compensating landowners for takings or reductions in property value has been opposed by some who argue updating the law to address this is not necessary. While consensus on other issues such as the need for increasing conservation incentives and the role states play in endangered species conservation has begun to emerge, one of the most debated aspects of ESA implementation continues to be whether the ESA is effectively conserving endangered and threatened species. While there have been significant strides in conserving individual species such as the whooping crane, red-cockaded woodpecker and gray wolf, few species have been delisted (removed from the endangered list) or downlisted (changed in status from endangered to threatened) because of successful ESA conservation efforts. Some argue that the number of recovered species is an unfair measure, asserting that the three decades the ESA has been in existence is an insufficient amount of time for the lengthy process of species recovery and point to listed species that have not gone extinct as evidence the ESA 'saves' species. From the opposing perspective, while recovery to the point of delisting may require a substantial amount of time for many species, after three decades more progress should be demonstrable through species that have recovered and been delisted. Even if a species has increased in numbers or distribution or the threats facing the species have been reduced, if it has not been delisted on the basis of recovery, the ESA's prohibitions and regulations remain applicable and the ESA should not be a 'one way street.' Of 40 total species removed from the list, 10 domestic species were delisted because of "recovery". Of 33 reclassified species, 10 domestic downlistings (a change from endangered to threatened status) reflected a reduced threat assessment which also allowed more flexibility in management. The FWS's most recent report to Congress (Fiscal years 2001-2002) shows that 77 percent of listed species fall in the 0 to 25 percent recovery achieved bracket and 2 percent fall in the 76 to 100 percent recovery achieved bracket. 39 percent of the FWS managed species are of uncertain status. Of those with an assessed trend, at one end of the spectrum are 3 percent possibly extinct, 1 percent occurring only in captivity and 21 percent declining and at the other end are 30 percent stable and 6 percent improving. These assessments however are subjective. Additionally, the assessment that a species is improving or stable may reflect, for example, a reduction in perceived threats or corrections to inaccurate threat assessments that stemmed from erroneous data rather than actual changes in species' trends that are demonstrated by improved numbers, distribution or other such measurements. Consequently, a meaningful assessment of conservation trends under the ESA using these data is not possible. The data used to list a number of species has been subsequently determined to be erroneous and species that likely do not merit classification as endangered or threatened remain listed. This can consume resources that could be directed to species that do merit listing. The assignment of recovery priorities appears highly skewed and the recovery priority for some species seems questionable. A meaningful distinction between endangered status and threatened status has been blurred as has been the framework for the mechanism of critical habitat. Expenditure reporting has improved but presents an incomplete picture of financial resources dedicated to endangered species. Workloads for litigation regarding activities such as consultation and listing under the ESA's complex structure compete for resources that could otherwise be directed at recovery efforts. The demands associated with ESA Section 4 determinations in combination with the pace of species listings and delistings, the number of possible future additions to the list and the economic impact of listings likely indicate that the current program is not sustainable. Close

• 21. [Image] Report of 1994 Workshop on the Correlation of Marine and Terrestrial Records of Climate Changes in the Western United States

  	Imprint from transmittal sheet; Distributed to depository libraries in microfiche; Shipping list no.: 97-0071-M; One ill. on 1 folded leaf in pocket; Includes bibliographical references
  	Citation × Citation Citation Abstract Copy Title: Report of 1994 Workshop on the Correlation of Marine and Terrestrial Records of Climate Changes in the Western United States Author: Workshop on the Correlation of Marine and Terrestrial Records of Climate Changes in the Western U.S. (3rd : 1994 : Watsonville, Calif.) Year: 1996, 2007, 2005 Imprint from transmittal sheet; Distributed to depository libraries in microfiche; Shipping list no.: 97-0071-M; One ill. on 1 folded leaf in pocket; Includes bibliographical references Title: Report of 1994 Workshop on the Correlation of Marine and Terrestrial Records of Climate Changes in the Western United States Author: Workshop on the Correlation of Marine and Terrestrial Records of Climate Changes in the Western U.S. (3rd : 1994 : Watsonville, Calif.) Year: 1996, 2007, 2005 Imprint from transmittal sheet; Distributed to depository libraries in microfiche; Shipping list no.: 97-0071-M; One ill. on 1 folded leaf in pocket; Includes bibliographical references Close

• 22. [Image] IMST review of the USFWS and NMFS 2001 biological opinions on management of the Klamath Reclamation Project and related reports: a report of the Independent Multidisciplinary Science Team, Oregon Plan for Salmon and Watersheds

  	This report is a review of scientific research done by various organizations involved in the Klamath Reclamation Project to assess the "status and management of coho salmon in the Klamath River and . . ...
  	Citation × Citation Citation Abstract Copy Title: IMST review of the USFWS and NMFS 2001 biological opinions on management of the Klamath Reclamation Project and related reports: a report of the Independent Multidisciplinary Science Team, Oregon Plan for Salmon and Watersheds Author: Independent Multidisciplinary Science Team (Oregon) Year: 2003, 2004 This report is a review of scientific research done by various organizations involved in the Klamath Reclamation Project to assess the "status and management of coho salmon in the Klamath River and . . . management of Upper Klamath Lake and its watershed"; "April 16, 2003"; Includes bibliographical references (p. 104-112) Title: IMST review of the USFWS and NMFS 2001 biological opinions on management of the Klamath Reclamation Project and related reports: a report of the Independent Multidisciplinary Science Team, Oregon Plan for Salmon and Watersheds Author: Independent Multidisciplinary Science Team (Oregon) Year: 2003, 2004 This report is a review of scientific research done by various organizations involved in the Klamath Reclamation Project to assess the "status and management of coho salmon in the Klamath River and . . . management of Upper Klamath Lake and its watershed"; "April 16, 2003"; Includes bibliographical references (p. 104-112) Close

• 23. [Image] Recovery plan for the native fishes of the Warner Basin and Alkali Subbasin : Warner sucker (threatened) Catostomus warnerensis, Hutton tui chub (threatened) Gila bicolor ssp. Foskett speckled dace (threatened) Rhinichthys osculus ssp

  	"April 1998"--P. [4] of cover; Includes bibliographical references (p. 57-66)
  	Citation × Citation Citation Abstract Copy Title: Recovery plan for the native fishes of the Warner Basin and Alkali Subbasin : Warner sucker (threatened) Catostomus warnerensis, Hutton tui chub (threatened) Gila bicolor ssp. Foskett speckled dace (threatened) Rhinichthys osculus ssp Author: U.S. Fish and Wildlife Service. Oregon State Office Year: 1998, 2004 "April 1998"--P. [4] of cover; Includes bibliographical references (p. 57-66) Title: Recovery plan for the native fishes of the Warner Basin and Alkali Subbasin : Warner sucker (threatened) Catostomus warnerensis, Hutton tui chub (threatened) Gila bicolor ssp. Foskett speckled dace (threatened) Rhinichthys osculus ssp Author: U.S. Fish and Wildlife Service. Oregon State Office Year: 1998, 2004 "April 1998"--P. [4] of cover; Includes bibliographical references (p. 57-66) Close

• 24. [Image] Groundwater investigation of Bonanza Springs, Yonna, Poe and Langel valleys

  	PURPOSE, SCOPE AND METHODOLOGY A reconnaissance study was designed to collect, compile, and analyze data to determine if ground-water use would interfere with surface water sources near Big Bonanza Springs. ...
  	Citation × Citation Citation Abstract Copy Title: Groundwater investigation of Bonanza Springs, Yonna, Poe and Langel valleys Author: Gorman, Kyle G. Year: 1994, 2004 PURPOSE, SCOPE AND METHODOLOGY A reconnaissance study was designed to collect, compile, and analyze data to determine if ground-water use would interfere with surface water sources near Big Bonanza Springs. The study was to last one year from July 1992 to June 1993. Periodic water level measurements and stream flow measurements have been made since June 1993, to create a more complete data set. Water level measurements in selected wells were made periodically to determine groundwater level fluctuations over time. A continuous water level recorder was installed in one well in September 1992 and is currently scheduled to run until spring 1994, when its status will be evaluated. The emphasis on work in the local area around Bonanza included monthly water level measurements, Lost River stream flow measurements, and Bonanza Springs weir measurements. This area has the highest concentration of wells, both domestic and irrigation, and is of particular interest because of the large aggregate discharge of groundwater in a short reach of the Lost River. To quantify the discharge of the Bonanza Springs, wading stream flow measurements were made above and below the section of the Lost River where groundwater is known to discharge. The difference between the two measurements was assumed to give the discharge of the springs in that reach. To correlate the overall flow of Bonanza Springs to the direct measurement of some of the discharge points, various-sized rectangular weirs were placed in the northern channel of the springs in the Big Bonanza Springs Park. The comparison could then be made by making sets of measurements at all locations in a single day. The total potential use was determined by summing the number of cubic feet per second (cfs) on the pending applications filed with OWRD for the appropriation of groundwater in the area within the study boundaries. This area coincides with the valley lowland areas. The total maximum rate of appropriation under terms of existing permits was determined by valley only in Langell Valley for the 1992 irrigation season. This was done by summing the individual rates in permits for irrigation, stock and domestic purposes, if any. This total included all issued permits and emergency drought permits exclusively from groundwater. Sample drill cuttings were collected from wells under construction during the study period within the study boundaries. The samples were examined in an effort to correlate geology defined in past studies with present knowledge. They were also used to conceptualize the subsurface geology. A video log of the well bore in which the continuous water level recorder was installed was done in early October 1992. Since this well was constructed prior to the requirement of a well drilling report, a video log of the rock types throughout the well bore was recorded. This information was important in evaluating static water level information also collected by the recorder. Title: Groundwater investigation of Bonanza Springs, Yonna, Poe and Langel valleys Author: Gorman, Kyle G. Year: 1994, 2004 PURPOSE, SCOPE AND METHODOLOGY A reconnaissance study was designed to collect, compile, and analyze data to determine if ground-water use would interfere with surface water sources near Big Bonanza Springs. The study was to last one year from July 1992 to June 1993. Periodic water level measurements and stream flow measurements have been made since June 1993, to create a more complete data set. Water level measurements in selected wells were made periodically to determine groundwater level fluctuations over time. A continuous water level recorder was installed in one well in September 1992 and is currently scheduled to run until spring 1994, when its status will be evaluated. The emphasis on work in the local area around Bonanza included monthly water level measurements, Lost River stream flow measurements, and Bonanza Springs weir measurements. This area has the highest concentration of wells, both domestic and irrigation, and is of particular interest because of the large aggregate discharge of groundwater in a short reach of the Lost River. To quantify the discharge of the Bonanza Springs, wading stream flow measurements were made above and below the section of the Lost River where groundwater is known to discharge. The difference between the two measurements was assumed to give the discharge of the springs in that reach. To correlate the overall flow of Bonanza Springs to the direct measurement of some of the discharge points, various-sized rectangular weirs were placed in the northern channel of the springs in the Big Bonanza Springs Park. The comparison could then be made by making sets of measurements at all locations in a single day. The total potential use was determined by summing the number of cubic feet per second (cfs) on the pending applications filed with OWRD for the appropriation of groundwater in the area within the study boundaries. This area coincides with the valley lowland areas. The total maximum rate of appropriation under terms of existing permits was determined by valley only in Langell Valley for the 1992 irrigation season. This was done by summing the individual rates in permits for irrigation, stock and domestic purposes, if any. This total included all issued permits and emergency drought permits exclusively from groundwater. Sample drill cuttings were collected from wells under construction during the study period within the study boundaries. The samples were examined in an effort to correlate geology defined in past studies with present knowledge. They were also used to conceptualize the subsurface geology. A video log of the well bore in which the continuous water level recorder was installed was done in early October 1992. Since this well was constructed prior to the requirement of a well drilling report, a video log of the rock types throughout the well bore was recorded. This information was important in evaluating static water level information also collected by the recorder. Close

• 25. [Image] Nitrogen and phosphorus loading from drained wetlands adjacent to Upper Klamath and Agency Lakes, Oregon

  	Two maps digitized separately; Includes bibliographical references (p. 44-49)
  	Citation × Citation Citation Abstract Copy Title: Nitrogen and phosphorus loading from drained wetlands adjacent to Upper Klamath and Agency Lakes, Oregon Author: Snyder, Daniel T. Year: 1997, 2005, 2004 Two maps digitized separately; Includes bibliographical references (p. 44-49) Title: Nitrogen and phosphorus loading from drained wetlands adjacent to Upper Klamath and Agency Lakes, Oregon Author: Snyder, Daniel T. Year: 1997, 2005, 2004 Two maps digitized separately; Includes bibliographical references (p. 44-49) Close

• 26. [Image] An assessment of ecosystem components in the interior Columbia Basin and portions of the Klamath and Great Basins [volume 1]

  	Quigley, Thomas M.; Arbelbide, Sylvia J., tech. eds. 1997. An assessment of ecosystem components in the interior Columbia basin and portions of the Klamath and Great Basins: volume 1. Gen. Tech. Rep. PNW-GTR-405. ...
  	Citation × Citation Citation Abstract Copy Title: An assessment of ecosystem components in the interior Columbia Basin and portions of the Klamath and Great Basins [volume 1] Author: Quigley, Thomas Milton; Arbelbide, S. J. (Sylvia J.) Year: 1997, 2008, 2005 Quigley, Thomas M.; Arbelbide, Sylvia J., tech. eds. 1997. An assessment of ecosystem components in the interior Columbia basin and portions of the Klamath and Great Basins: volume 1. Gen. Tech. Rep. PNW-GTR-405. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 4 vol. (Quigley, Thomas M., tech. ed.; The Interior Columbia Basin Ecosystem Management Project: Scientific Assessment). The Assessment of Ecosystem Components in the Interior Columbia Basin and Portions of the Klamath and Great Basins provides detailed information about current conditions and trends for the biophysical and social systems within the Basin. This information can be used by land managers to develop broad land management goals and priorities and provides the context for decisions specific to smaller geographic areas. The Assessment area covers about 8 percent of the U.S. land area, 24 percent of the Nation's National Forest System lands, 10 percent of the Nation's BLM-administered lands, and contains about 1.2 percent of the Nation's population. This results in a population density that is less than one-sixth of the U.S. average. The area has experienced recent, rapid population growth and generally has a robust, diverse economy. As compared to historic conditions, the terrestrial, aquatic, forest, and rangeland systems have undergone dramatic changes. Forested landscapes are more susceptible to fire, insect, and disease than under historic conditions. Rangelands are highly susceptible to noxious weed invasion. The disturbance regimes that operate on forest and rangeland have changed substantially, with lethal fires dominating many areas where non-lethal fires were the norm historically. Terrestrial habitats that have experienced the greatest decline include the native grassland, native shrubland, and old forest structures. There are areas within the Assessment area that have higher diversity than others. Aquatic systems are now more fragmented and isolated than historically and the introduction of non-native fish species has complicated current status of native fishes. Core habitat and population centers do remain as building blocks for restoration. Social and economic conditions within the Assessment area vary considerably, depending to a great extent on population, diversity of employment opportunities, and changing demographics. Those counties with the higher population densities and greater diversity of employment opportunities are generally more resilient to economic downturns. This Assessment provides a rich information base, including over 170 mapped themes with associated models and databases, from which future decisions can benefit. Keywords: Columbia basin, biophysical systems, social systems, ecosystem. Title: An assessment of ecosystem components in the interior Columbia Basin and portions of the Klamath and Great Basins [volume 1] Author: Quigley, Thomas Milton; Arbelbide, S. J. (Sylvia J.) Year: 1997, 2008, 2005 Quigley, Thomas M.; Arbelbide, Sylvia J., tech. eds. 1997. An assessment of ecosystem components in the interior Columbia basin and portions of the Klamath and Great Basins: volume 1. Gen. Tech. Rep. PNW-GTR-405. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 4 vol. (Quigley, Thomas M., tech. ed.; The Interior Columbia Basin Ecosystem Management Project: Scientific Assessment). The Assessment of Ecosystem Components in the Interior Columbia Basin and Portions of the Klamath and Great Basins provides detailed information about current conditions and trends for the biophysical and social systems within the Basin. This information can be used by land managers to develop broad land management goals and priorities and provides the context for decisions specific to smaller geographic areas. The Assessment area covers about 8 percent of the U.S. land area, 24 percent of the Nation's National Forest System lands, 10 percent of the Nation's BLM-administered lands, and contains about 1.2 percent of the Nation's population. This results in a population density that is less than one-sixth of the U.S. average. The area has experienced recent, rapid population growth and generally has a robust, diverse economy. As compared to historic conditions, the terrestrial, aquatic, forest, and rangeland systems have undergone dramatic changes. Forested landscapes are more susceptible to fire, insect, and disease than under historic conditions. Rangelands are highly susceptible to noxious weed invasion. The disturbance regimes that operate on forest and rangeland have changed substantially, with lethal fires dominating many areas where non-lethal fires were the norm historically. Terrestrial habitats that have experienced the greatest decline include the native grassland, native shrubland, and old forest structures. There are areas within the Assessment area that have higher diversity than others. Aquatic systems are now more fragmented and isolated than historically and the introduction of non-native fish species has complicated current status of native fishes. Core habitat and population centers do remain as building blocks for restoration. Social and economic conditions within the Assessment area vary considerably, depending to a great extent on population, diversity of employment opportunities, and changing demographics. Those counties with the higher population densities and greater diversity of employment opportunities are generally more resilient to economic downturns. This Assessment provides a rich information base, including over 170 mapped themes with associated models and databases, from which future decisions can benefit. Keywords: Columbia basin, biophysical systems, social systems, ecosystem. Close

• 27. [Image] Soils of the Klamath Indian Reservation; interim report, June 11, 1958

  	TABLE OF CONTENTS PART I INTRODUCTION 18 - 11 History and ethnology 18 Irrigated area table 19 Cultural geography 19 General physiographic features 262e . .3 Physiographic areas and farming 1d CLIMATE ...
  	Citation × Citation Citation Abstract Copy Title: Soils of the Klamath Indian Reservation; interim report, June 11, 1958 Author: United States. Bureau of Indian Affairs Year: 1958, 2005, 2004 TABLE OF CONTENTS PART I INTRODUCTION 18 - 11 History and ethnology 18 Irrigated area table 19 Cultural geography 19 General physiographic features 262e . .3 Physiographic areas and farming 1d CLIMATE 182 - 18 Climatic table, Sprague River, Oregon 185 Precipitation table , Chiloquin, Oregon 186 Temperature table, Chiloquin, Oregon 187 Climatic table, Fort Klamath, Oregon 188 VEGETATION 189 - 25 GEOLOGY 196 - 51 Hydrography: rivers, lakes, marshes, ground water 196 Relief and geological formations. 262e .32 Diatomite - tuff formation 262e . 1c4 Pliocene sediments of the Modoc Point area 262e.. 37 Faulted tuff formation 1c9 Pumice tuff formation.. 1d0 Pumice mantle and pumice flows ........ 262e.... .........40 Table of chemical analyses of pumice and scoria 1d5 Geology Map 262e . 262e 221 BIBLIOGRAPHY 262e 262e...52 PART II DESCRIPTIONS OF SOILS 223 - 60 Classification and survey 262e 262e.. 262e... 53 Soil profile and nomenclature. .... 262e...53 Chestnut Soils 262e 224 "Western" Brown Forest Soils 225 Regosol Soils . . 262e. 262e......56 Solonetz Soils 262e.....57 Halomorphic Soils 262e 228 Hydromorphic Soils 262e... 229 Soil Association Map 262e 229 KEY TO SOIL SERIES 262e61 - 63 SOIL SERIES AND MAPPING UNIT DESCRIPTIONS 134 ~ 254 APPENDIX 1955 - 297 Soil Series and mapping unit index. 2620. . . . 255 Glossary of terms 263f 262e. . . . 272 Table of soil analyses (Oregon State College)... 1989 Table of irrigation water quality (Oregon State College) 1990 Table of conductivity and reaction. . . . 1991 Table of resistance of saturated paste 262e296 Title: Soils of the Klamath Indian Reservation; interim report, June 11, 1958 Author: United States. Bureau of Indian Affairs Year: 1958, 2005, 2004 TABLE OF CONTENTS PART I INTRODUCTION 18 - 11 History and ethnology 18 Irrigated area table 19 Cultural geography 19 General physiographic features 262e . .3 Physiographic areas and farming 1d CLIMATE 182 - 18 Climatic table, Sprague River, Oregon 185 Precipitation table , Chiloquin, Oregon 186 Temperature table, Chiloquin, Oregon 187 Climatic table, Fort Klamath, Oregon 188 VEGETATION 189 - 25 GEOLOGY 196 - 51 Hydrography: rivers, lakes, marshes, ground water 196 Relief and geological formations. 262e .32 Diatomite - tuff formation 262e . 1c4 Pliocene sediments of the Modoc Point area 262e.. 37 Faulted tuff formation 1c9 Pumice tuff formation.. 1d0 Pumice mantle and pumice flows ........ 262e.... .........40 Table of chemical analyses of pumice and scoria 1d5 Geology Map 262e . 262e 221 BIBLIOGRAPHY 262e 262e...52 PART II DESCRIPTIONS OF SOILS 223 - 60 Classification and survey 262e 262e.. 262e... 53 Soil profile and nomenclature. .... 262e...53 Chestnut Soils 262e 224 "Western" Brown Forest Soils 225 Regosol Soils . . 262e. 262e......56 Solonetz Soils 262e.....57 Halomorphic Soils 262e 228 Hydromorphic Soils 262e... 229 Soil Association Map 262e 229 KEY TO SOIL SERIES 262e61 - 63 SOIL SERIES AND MAPPING UNIT DESCRIPTIONS 134 ~ 254 APPENDIX 1955 - 297 Soil Series and mapping unit index. 2620. . . . 255 Glossary of terms 263f 262e. . . . 272 Table of soil analyses (Oregon State College)... 1989 Table of irrigation water quality (Oregon State College) 1990 Table of conductivity and reaction. . . . 1991 Table of resistance of saturated paste 262e296 Close

• 28. [Image] Oregon Plan for Salmon and Watersheds biennial report, 2005-2007

  	The Oregon Plan for Salmon and Watersheds Biennial Report 2005-2007. This is the sixth report on the Oregon Plan for Salmon and Watersheds. The report provides an update on the accomplishments and continuing ...
  	Citation × Citation Citation Abstract Copy Title: Oregon Plan for Salmon and Watersheds biennial report, 2005-2007 Author: Oregon Watershed Enhancement Board Year: 2006, 2007 The Oregon Plan for Salmon and Watersheds Biennial Report 2005-2007. This is the sixth report on the Oregon Plan for Salmon and Watersheds. The report provides an update on the accomplishments and continuing efforts of people throughout Oregon to improve and protect clean water and recover and maintain healthy populations offish and wildlife in our watersheds. The Oregon Plan is unique because it engages communities in the restoration and long-term stewardship of their watersheds. This extraordinary effort encourages local partnerships and voluntary actions to improve the conditions of our watersheds. Over the years, these actions have made Oregon a national leader in local cooperative conservation. This report collects project and condition data, voluntary private lands restoration information, and agency program accomplishments under the Oregon Plan. Consistent with the past two reports, this document continues to provide specific data on each of the state's fifteen reporting basins. A new element to this report is the inclusion of stories about the people, partnerships, and on-the-ground projects that are benefiting watersheds and communities across the state. Thanks to the many Oregon Plan partners who contributed to this report. Thomas M. Byler Executive Director Oregon Watershed Enhancement Board Title: Oregon Plan for Salmon and Watersheds biennial report, 2005-2007 Author: Oregon Watershed Enhancement Board Year: 2006, 2007 The Oregon Plan for Salmon and Watersheds Biennial Report 2005-2007. This is the sixth report on the Oregon Plan for Salmon and Watersheds. The report provides an update on the accomplishments and continuing efforts of people throughout Oregon to improve and protect clean water and recover and maintain healthy populations offish and wildlife in our watersheds. The Oregon Plan is unique because it engages communities in the restoration and long-term stewardship of their watersheds. This extraordinary effort encourages local partnerships and voluntary actions to improve the conditions of our watersheds. Over the years, these actions have made Oregon a national leader in local cooperative conservation. This report collects project and condition data, voluntary private lands restoration information, and agency program accomplishments under the Oregon Plan. Consistent with the past two reports, this document continues to provide specific data on each of the state's fifteen reporting basins. A new element to this report is the inclusion of stories about the people, partnerships, and on-the-ground projects that are benefiting watersheds and communities across the state. Thanks to the many Oregon Plan partners who contributed to this report. Thomas M. Byler Executive Director Oregon Watershed Enhancement Board Close

• 29. [Image] Geology and ground-water resources of the Swan Lake-Yonna Valleys area, Klamath County, Oregon

  	Abstract The Swan Lake-Yonna Valleys area consists of two intermountain valleys with their subordinate side valleys adjoining slopes, and mountainous boundary ridges, In all the area covered is about 256 ...
  	Citation × Citation Citation Abstract Copy Title: Geology and ground-water resources of the Swan Lake-Yonna Valleys area, Klamath County, Oregon Author: Meyers, Joseph D. Year: 1952, 2007, 2005 Abstract The Swan Lake-Yonna Valleys area consists of two intermountain valleys with their subordinate side valleys adjoining slopes, and mountainous boundary ridges, In all the area covered is about 256 square miles but the essential agricultural sections are restricted to the floors of Swan Lake and Yonna valleys with their respective subsidiary extensions of Pine Flats and Alkali Lake flats, a valley-floor area totaling about 90 square miles The floors of Swan Lake Valley and Yonna Valley lie at an altitude of about U52OO feet but the mountainous boundary ridges rise generally to 6000 feeto Yonna Valley is largely drained to Lost River by Buck Creek but also in part to Alkali Lakeo Swan Lake Valley and Pine Flats have only internal drainage. The Swan Lake Valley floor is the top of a deep alluvial fill, while Yonna Valley floor is mainly an erosional surface sloping to lines of through drainage Precipitation is about lit inches annually on the valley floors 9 but must be much more, possibly 18 to 24 inches, on the higher parts of the drainage basins. The growing season is short and killing frosts do occur in late spring and early fall. The rock units forming the bedrock structure of the area are consolidated or semiconsolidated rocks of Tertiary age and are largely of volcanic-flow and volcanic-sedimentary originc They consist of three main elements, a lower lava-rock unit, a sedimentary and volcanic-sedimentary unit, and an upper lava-rock unito The unconsolidated deposits are the older alluvium of Quaternary (and in part of late-Tertiary) age and the younger alluvium of Quaternary age0 The bedrock is faulted and deformed particularly so along a northwest-southeast set of fault lines that have given a remarkable linearity to the topography. Unpublished records subject to revision Ground water occurs below a regional water table that slopes south-ward to the level of the Lost Rivero The upper lava rocks and the lower lava rocks contain the principal permeable zones that occur beneath the areao Breccia and other porous zones in those rocks in places yield water to wells at a rate as large as 35OOO gallons per minute with but 1 or 2 feet of drawdowno The economical construction of irrigation wells requires the determination of the best possible location at which those rocks may be tapped at shallow depth below the level of the water tableo The ground water in general relatively low in dissolved mineral matter and is but slightly to moderately hard and would be considered chemically satisfactory for most uaeso Irrigation is the principal use of the ground water in the area north of the Horsefly Irrigation Districto There 3? wells supplied about 6,000 acre-feet of water to about 3800 acres of land in 1950. Water-level records obtained since 19U8 and approximations of the probable annual recharge from precipitation indicate that the present withdrawals are considerably less than the annual increment of the ground-water recharge, Rough estimates indicate that an increase in withdrawals of as much as 100 percent or more can take place before ground-water levels, by a persistent lowering, will begin to indicate that the annual replenishment is being exceeded. Title: Geology and ground-water resources of the Swan Lake-Yonna Valleys area, Klamath County, Oregon Author: Meyers, Joseph D. Year: 1952, 2007, 2005 Abstract The Swan Lake-Yonna Valleys area consists of two intermountain valleys with their subordinate side valleys adjoining slopes, and mountainous boundary ridges, In all the area covered is about 256 square miles but the essential agricultural sections are restricted to the floors of Swan Lake and Yonna valleys with their respective subsidiary extensions of Pine Flats and Alkali Lake flats, a valley-floor area totaling about 90 square miles The floors of Swan Lake Valley and Yonna Valley lie at an altitude of about U52OO feet but the mountainous boundary ridges rise generally to 6000 feeto Yonna Valley is largely drained to Lost River by Buck Creek but also in part to Alkali Lakeo Swan Lake Valley and Pine Flats have only internal drainage. The Swan Lake Valley floor is the top of a deep alluvial fill, while Yonna Valley floor is mainly an erosional surface sloping to lines of through drainage Precipitation is about lit inches annually on the valley floors 9 but must be much more, possibly 18 to 24 inches, on the higher parts of the drainage basins. The growing season is short and killing frosts do occur in late spring and early fall. The rock units forming the bedrock structure of the area are consolidated or semiconsolidated rocks of Tertiary age and are largely of volcanic-flow and volcanic-sedimentary originc They consist of three main elements, a lower lava-rock unit, a sedimentary and volcanic-sedimentary unit, and an upper lava-rock unito The unconsolidated deposits are the older alluvium of Quaternary (and in part of late-Tertiary) age and the younger alluvium of Quaternary age0 The bedrock is faulted and deformed particularly so along a northwest-southeast set of fault lines that have given a remarkable linearity to the topography. Unpublished records subject to revision Ground water occurs below a regional water table that slopes south-ward to the level of the Lost Rivero The upper lava rocks and the lower lava rocks contain the principal permeable zones that occur beneath the areao Breccia and other porous zones in those rocks in places yield water to wells at a rate as large as 35OOO gallons per minute with but 1 or 2 feet of drawdowno The economical construction of irrigation wells requires the determination of the best possible location at which those rocks may be tapped at shallow depth below the level of the water tableo The ground water in general relatively low in dissolved mineral matter and is but slightly to moderately hard and would be considered chemically satisfactory for most uaeso Irrigation is the principal use of the ground water in the area north of the Horsefly Irrigation Districto There 3? wells supplied about 6,000 acre-feet of water to about 3800 acres of land in 1950. Water-level records obtained since 19U8 and approximations of the probable annual recharge from precipitation indicate that the present withdrawals are considerably less than the annual increment of the ground-water recharge, Rough estimates indicate that an increase in withdrawals of as much as 100 percent or more can take place before ground-water levels, by a persistent lowering, will begin to indicate that the annual replenishment is being exceeded. Close

• 30. [Image] Hydrogeology and paleohydrology in the Williamson River basin, Klamath County, Oregon

  	Abstract An abstract of the thesis of Jeffrey Scott Conaway for the Master of Science in Geology presented December 8, 1999. Title: Hydrogeology and Paleohydrology in the Williamson River Basin, Klamath ...
  	Citation × Citation Citation Abstract Copy Title: Hydrogeology and paleohydrology in the Williamson River basin, Klamath County, Oregon Author: Conaway, Jeffrey Scott Year: 2000, 2008, 2005 Abstract An abstract of the thesis of Jeffrey Scott Conaway for the Master of Science in Geology presented December 8, 1999. Title: Hydrogeology and Paleohydrology in the Williamson River Basin, Klamath County, Oregon. Stress on the water resources of the Williamson River basin has led to their regulation to protect important habitat. Quantification of this resource is required for accurate regulation. A portion of this study is a hydrogeologic reconnaissance that suggests directions for future work. Measured discharge and deuterium isotope data from points above and below the Williamson River canyon indicate that the river receives 99% of its discharge from ground water during periods of low flow. The principle aquifer of the southern Klamath Marsh is a fractured basalt, while continental sediments that are up to 200 m thick provide high artesian yields south of the canyon. The disparity between high precipitation on the basin's western margin and the low and variable discharge of the Williamson River at the Kirk Sill suggests either the presence of a fault zone that interrupts the flow of ground water or deep flow paths that do not surface within Klamath Marsh. Three terraces line the eastern edge of Klamath Marsh at approximate elevations of 1380, 1385, and 1397 m. The lowest terrace is late Holocene and cut into marsh sediment and reworked deposits from the pyroclastic eruptions of Mount Mazama. The middle terrace is planed into bedrock and formed when Pleistocene Lake Chemult occupied this basin. The upper terrace, a strand line, is delineated by a slope break that separates reworked pyroclastic deposits from undisturbed pyroclastic fall. Formation of this terrace occurred when pyroclastic flows from the cataclysmic eruption of Mount Mazama formed a blockage in the Williamson River canyon. Resultant backflooding reworked pyroclastic deposits and rafted pumice up to an approximate elevation of 1400 m. The blockage failed catastrophically from overtopping, draining 5.7 x 109 m3 of water, scouring the canyon and producing an erratic boulder deposit at the mouth of the canyon. Upstream evidence of rapid draining includes linear scour channels incised in pyroclastic-flow deposits and scouring of the broad Pleistocene terrace. Paleohydraulic reconstruction of down stream flooding using a flow-competence equation and a physically based dam-break model yield a peak discharge of 1.3 x 104 m3 s"1. Title: Hydrogeology and paleohydrology in the Williamson River basin, Klamath County, Oregon Author: Conaway, Jeffrey Scott Year: 2000, 2008, 2005 Abstract An abstract of the thesis of Jeffrey Scott Conaway for the Master of Science in Geology presented December 8, 1999. Title: Hydrogeology and Paleohydrology in the Williamson River Basin, Klamath County, Oregon. Stress on the water resources of the Williamson River basin has led to their regulation to protect important habitat. Quantification of this resource is required for accurate regulation. A portion of this study is a hydrogeologic reconnaissance that suggests directions for future work. Measured discharge and deuterium isotope data from points above and below the Williamson River canyon indicate that the river receives 99% of its discharge from ground water during periods of low flow. The principle aquifer of the southern Klamath Marsh is a fractured basalt, while continental sediments that are up to 200 m thick provide high artesian yields south of the canyon. The disparity between high precipitation on the basin's western margin and the low and variable discharge of the Williamson River at the Kirk Sill suggests either the presence of a fault zone that interrupts the flow of ground water or deep flow paths that do not surface within Klamath Marsh. Three terraces line the eastern edge of Klamath Marsh at approximate elevations of 1380, 1385, and 1397 m. The lowest terrace is late Holocene and cut into marsh sediment and reworked deposits from the pyroclastic eruptions of Mount Mazama. The middle terrace is planed into bedrock and formed when Pleistocene Lake Chemult occupied this basin. The upper terrace, a strand line, is delineated by a slope break that separates reworked pyroclastic deposits from undisturbed pyroclastic fall. Formation of this terrace occurred when pyroclastic flows from the cataclysmic eruption of Mount Mazama formed a blockage in the Williamson River canyon. Resultant backflooding reworked pyroclastic deposits and rafted pumice up to an approximate elevation of 1400 m. The blockage failed catastrophically from overtopping, draining 5.7 x 109 m3 of water, scouring the canyon and producing an erratic boulder deposit at the mouth of the canyon. Upstream evidence of rapid draining includes linear scour channels incised in pyroclastic-flow deposits and scouring of the broad Pleistocene terrace. Paleohydraulic reconstruction of down stream flooding using a flow-competence equation and a physically based dam-break model yield a peak discharge of 1.3 x 104 m3 s"1. Close

• 31. [Article] Geology of the Breitenbush Hot Springs area, Cascade Range, Oregon

  The Breitenbush Hot Springs area lies on the boundary of folded middle to late Tertiary Western Cascade rocks and younger High Cascade rocks. Within the mapped area the Western Cascade rocks are represented ...

  Citation × Citation Citation Abstract Copy Title: Geology of the Breitenbush Hot Springs area, Cascade Range, Oregon Author: Clayton, Clifford Michael Year: 1976 The Breitenbush Hot Springs area lies on the boundary of folded middle to late Tertiary Western Cascade rocks and younger High Cascade rocks. Within the mapped area the Western Cascade rocks are represented by four formations. The Detroit Beds, a sequence of interstratified tuffaceous sandstone, mudflow breccia, and tuff, is overlain unconformably by the Breitenbush Tuff. The Breitenbush Tuff consists of three units of welded pumice-rich crystal-vitric ash-flow tuffs interbedded with tuffaceous sedimentary rocks. The Outerson Formation unconformably overlies the Breitenbush Tuff and consists primarily of basaltic lava and breccia. The Outerson Formation includes three localized members: a basal, glassy, aphanitic basalt, the Lake Leone Sediments, and the Outerson Tuff. The Outerson Formation is cut by a number of feeder dikes and plugs and is unconformably overlain by the Cheat Creek Sediments, composed of volcanic sedimentary rocks and a distinctive basaltic tuff. The Western Cascade formations total more than 1660 m {5500 ft) of strata and range from Oligocene to Pliocene in age. The High Cascade rocks are represented by two formations: the Triangulation Peak Volcanics of basalt and andesite lava and breccia, lying unconformably atop the Cheat Creek Sediments; and unconformably beneath the Collowash Volcanics, a series of thin basaltic lava flows and breccias. The Western and High Cascade rocks are covered extensively by surficial deposits, primarily glacial drift. The High Cascade formations are at least 840 m (2800 ft) thick, ranging in age from Pliocene to Pliestocene. The Western Cascade rocks have been folded and faulted in the Breitenbush Hot Springs area, and form the eastern limb of the north-trending Breitenbush Anticline. The folded rocks and the erosional unconformities between the rock units probably represent two local episodes of orogeny: one in early to middle Miocene and another in late Pliocene to Pleistocene time. The Outerson Formation represents a depositional sequence between the periods of uplift and deformation. Faulting accompanied the orogenic sequences. The primary volcanic landforms in the area have been destroyed by erosion but skeletal remains of High Cascade volcanoes are recognized. Stream erosion and glaciation are responsible for the present landforms. Breitenbush Hot Springs occurs, in part, along basaltic dikes which channel the water through impermeable Breitenbush Tuff. The dikes are believed to be associated with the Outerson basalts. The Hot Springs discharge upwards at 3400 l/min. (900 gpm) of water at temperatures up to 92°C (198°F). Title: Geology of the Breitenbush Hot Springs area, Cascade Range, Oregon Author: Clayton, Clifford Michael Year: 1976 The Breitenbush Hot Springs area lies on the boundary of folded middle to late Tertiary Western Cascade rocks and younger High Cascade rocks. Within the mapped area the Western Cascade rocks are represented by four formations. The Detroit Beds, a sequence of interstratified tuffaceous sandstone, mudflow breccia, and tuff, is overlain unconformably by the Breitenbush Tuff. The Breitenbush Tuff consists of three units of welded pumice-rich crystal-vitric ash-flow tuffs interbedded with tuffaceous sedimentary rocks. The Outerson Formation unconformably overlies the Breitenbush Tuff and consists primarily of basaltic lava and breccia. The Outerson Formation includes three localized members: a basal, glassy, aphanitic basalt, the Lake Leone Sediments, and the Outerson Tuff. The Outerson Formation is cut by a number of feeder dikes and plugs and is unconformably overlain by the Cheat Creek Sediments, composed of volcanic sedimentary rocks and a distinctive basaltic tuff. The Western Cascade formations total more than 1660 m {5500 ft) of strata and range from Oligocene to Pliocene in age. The High Cascade rocks are represented by two formations: the Triangulation Peak Volcanics of basalt and andesite lava and breccia, lying unconformably atop the Cheat Creek Sediments; and unconformably beneath the Collowash Volcanics, a series of thin basaltic lava flows and breccias. The Western and High Cascade rocks are covered extensively by surficial deposits, primarily glacial drift. The High Cascade formations are at least 840 m (2800 ft) thick, ranging in age from Pliocene to Pliestocene. The Western Cascade rocks have been folded and faulted in the Breitenbush Hot Springs area, and form the eastern limb of the north-trending Breitenbush Anticline. The folded rocks and the erosional unconformities between the rock units probably represent two local episodes of orogeny: one in early to middle Miocene and another in late Pliocene to Pleistocene time. The Outerson Formation represents a depositional sequence between the periods of uplift and deformation. Faulting accompanied the orogenic sequences. The primary volcanic landforms in the area have been destroyed by erosion but skeletal remains of High Cascade volcanoes are recognized. Stream erosion and glaciation are responsible for the present landforms. Breitenbush Hot Springs occurs, in part, along basaltic dikes which channel the water through impermeable Breitenbush Tuff. The dikes are believed to be associated with the Outerson basalts. The Hot Springs discharge upwards at 3400 l/min. (900 gpm) of water at temperatures up to 92°C (198°F). Close

• 32. [Article] Quaternary Chronology and Stratigraphy of Mickey Springs, Oregon

  Mickey Springs in the Alvord Desert, southeast Oregon, is analogous to other Basin and Range hydrothermal systems where the requisite conditions of heat source and permeable pathways are met through crustal ...

  Citation × Citation Citation Abstract Copy Title: Quaternary Chronology and Stratigraphy of Mickey Springs, Oregon Author: Mowbray, Leslie Allen Year: 2015 Mickey Springs in the Alvord Desert, southeast Oregon, is analogous to other Basin and Range hydrothermal systems where the requisite conditions of heat source and permeable pathways are met through crustal thinning due to normal faulting. This study examines the morphology and lifespan of near-surface spring features through use of ground penetrating radar, thermoluminescence (TL) dating, and elevation modeling. Duration of hydrothermal activity at Mickey Springs has not previously been determined, and age determinations of sinter at the site are conflicting. The reason for and timing of this change in silica saturation in the hydrothermal fluid has not been resolved. Three morphologies of silica sinter deposition have been identified at Mickey Springs. These are (1) well-sorted, fine-grained sandstone with ripple marks, cross beds and preserved root casts, to poorly-sorted conglomerate of primarily basalt clasts, both cemented by coeval silica deposition, (2) large depressions (12-32 m diameter) rimmed with sinter, characterized by fine silt and clay blanketing a sinter apron and infilling the central depression, and (3) quaquaversal sinter mounds identified by outcropping pool-edge sinter typically surrounding a shallow depression of loose sediment. Silica-cemented sandstone and conglomerate were the first features formed by coeval hydrothermal processes at the site, and were emplaced prior to 30 kya as suggested by structural and stratigraphic relationships. Structure between two interacting fault tips may have constrained the extent of silica cementation. By 30 kya, a left-stepping fault oriented roughly north/south further constrained the near-surface permeable zone. TL dates from sediment stratigraphically below and above sinter aprons around mounds and depressions (former spring vents) indicate sinter deposition between 30 and 20 kya. Location of these features was dictated by development of the left-stepping fault. As pluvial Lake Alvord filled at the end of the Pleistocene, lake sediment filled most vents, which were largely inactive, with fine-grained silt and clay. Today, hydrothermal activity persists in two modes: (1) The current high-temperature springs, steam vents and mudpots concentrated in a 50 x 50 m area south of the sinter mounds and depressions, and (2) scattered springs and steam vents that exploit previous permeable pathways that once provided the hydrothermal fluid which precipitated the sinter aprons. Currently there is no active silica sinter deposition at Mickey Springs. Structures and stratigraphic relationships identified through this study favor a transport-limited and structurally controlled model of fluid transport. Sinter deposition is determined to have occurred before the most recent highstand of pluvial Lake Alvord. A climate driven model, where groundwater recharge from pluvial Lake Alvord circulates to a deep heat source and enhances spring discharge, is not supported by these findings, as no evidence was found for sinter precipitation after the drying of the lake. Future studies of other hydrothermal systems in the Basin and Range may reveal that permeable pathways along local structures are the primary drivers in this region. Title: Quaternary Chronology and Stratigraphy of Mickey Springs, Oregon Author: Mowbray, Leslie Allen Year: 2015 Mickey Springs in the Alvord Desert, southeast Oregon, is analogous to other Basin and Range hydrothermal systems where the requisite conditions of heat source and permeable pathways are met through crustal thinning due to normal faulting. This study examines the morphology and lifespan of near-surface spring features through use of ground penetrating radar, thermoluminescence (TL) dating, and elevation modeling. Duration of hydrothermal activity at Mickey Springs has not previously been determined, and age determinations of sinter at the site are conflicting. The reason for and timing of this change in silica saturation in the hydrothermal fluid has not been resolved. Three morphologies of silica sinter deposition have been identified at Mickey Springs. These are (1) well-sorted, fine-grained sandstone with ripple marks, cross beds and preserved root casts, to poorly-sorted conglomerate of primarily basalt clasts, both cemented by coeval silica deposition, (2) large depressions (12-32 m diameter) rimmed with sinter, characterized by fine silt and clay blanketing a sinter apron and infilling the central depression, and (3) quaquaversal sinter mounds identified by outcropping pool-edge sinter typically surrounding a shallow depression of loose sediment. Silica-cemented sandstone and conglomerate were the first features formed by coeval hydrothermal processes at the site, and were emplaced prior to 30 kya as suggested by structural and stratigraphic relationships. Structure between two interacting fault tips may have constrained the extent of silica cementation. By 30 kya, a left-stepping fault oriented roughly north/south further constrained the near-surface permeable zone. TL dates from sediment stratigraphically below and above sinter aprons around mounds and depressions (former spring vents) indicate sinter deposition between 30 and 20 kya. Location of these features was dictated by development of the left-stepping fault. As pluvial Lake Alvord filled at the end of the Pleistocene, lake sediment filled most vents, which were largely inactive, with fine-grained silt and clay. Today, hydrothermal activity persists in two modes: (1) The current high-temperature springs, steam vents and mudpots concentrated in a 50 x 50 m area south of the sinter mounds and depressions, and (2) scattered springs and steam vents that exploit previous permeable pathways that once provided the hydrothermal fluid which precipitated the sinter aprons. Currently there is no active silica sinter deposition at Mickey Springs. Structures and stratigraphic relationships identified through this study favor a transport-limited and structurally controlled model of fluid transport. Sinter deposition is determined to have occurred before the most recent highstand of pluvial Lake Alvord. A climate driven model, where groundwater recharge from pluvial Lake Alvord circulates to a deep heat source and enhances spring discharge, is not supported by these findings, as no evidence was found for sinter precipitation after the drying of the lake. Future studies of other hydrothermal systems in the Basin and Range may reveal that permeable pathways along local structures are the primary drivers in this region. Close

• 33. [Article] Late Pleistocene and recent archaeology and geomorphology of the south shore of Harney Lake, Oregon

  The present study was a response to the discovery of two artifacts found in a ditch wall near Harney Lake, Oregon. These were lying on a buried lake floor that appeared to be of late Pleistocene or early ...

  Citation × Citation Citation Abstract Copy Title: Late Pleistocene and recent archaeology and geomorphology of the south shore of Harney Lake, Oregon Author: Gehr, Keith Donald Year: 1980 The present study was a response to the discovery of two artifacts found in a ditch wall near Harney Lake, Oregon. These were lying on a buried lake floor that appeared to be of late Pleistocene or early Recent age. Other sediments exposed in the ditch seemed to relate to at least some of the phases of the pluvial lake sequence in the Harney Basin. Three problems were considered: (1) the geomorphology and dating of the pluvial lake stillstands, (2) whether the original artifacts were part of a larger early site, and (3) whether there was any relationship between archaeological sites and geomorphic features in the area. These problems were approached in the field by stratigraphic mapping of exposed sediments and by an archaeological survey of a defined study area. Test excavations were made adjacent to the location of the original artifact discovery to search for other cultural material. Beachline records of four stillstands of Pluvial Lake Malheur are preserved in the exposed sediments. The youngest beachline is undated. Three others were 14C dated from associated fossil molluscs at 32,000, 9620 and 8680 B.P. At least in the case of the 8680 B.P. lake, the Harney Basin was filled to overflowing and was a part of the Columbia River system. The Voltage basalt flow, which dammed the outlet of the Basin in Malheur Gap, was in place by 32,000 years ago. There is no evidence for a diversion of the Basin outlet to Crane Gap following this event. Molluscan fossils and diatoms were used, along with soil texture analyses, to help identify and differentiate sedimentary deposits and to draw environmental inferences. Artifacts were found both on and beneath buried beach deposits of the 8680 B.P. lake. Four of the five sites in the study area were either on wave-cut terraces or other lakeshore features associated with this lake. Diagnostic artifacts are Lind Coulee points, crescents, basally ground leaf-shaped points, and what are apparently true blades. The sites seem to have been located to take advantage of shallow water littoral zone resources. Fish may have been an important dietary item of the early Harney Basin dwellers. Large salmonid vertebrae from fish in the 10 kg weight class are found on the playa. By using the relationship between landforms and elevations it may be possible to predict the general age class of other sites on the margin of the playas. Title: Late Pleistocene and recent archaeology and geomorphology of the south shore of Harney Lake, Oregon Author: Gehr, Keith Donald Year: 1980 The present study was a response to the discovery of two artifacts found in a ditch wall near Harney Lake, Oregon. These were lying on a buried lake floor that appeared to be of late Pleistocene or early Recent age. Other sediments exposed in the ditch seemed to relate to at least some of the phases of the pluvial lake sequence in the Harney Basin. Three problems were considered: (1) the geomorphology and dating of the pluvial lake stillstands, (2) whether the original artifacts were part of a larger early site, and (3) whether there was any relationship between archaeological sites and geomorphic features in the area. These problems were approached in the field by stratigraphic mapping of exposed sediments and by an archaeological survey of a defined study area. Test excavations were made adjacent to the location of the original artifact discovery to search for other cultural material. Beachline records of four stillstands of Pluvial Lake Malheur are preserved in the exposed sediments. The youngest beachline is undated. Three others were 14C dated from associated fossil molluscs at 32,000, 9620 and 8680 B.P. At least in the case of the 8680 B.P. lake, the Harney Basin was filled to overflowing and was a part of the Columbia River system. The Voltage basalt flow, which dammed the outlet of the Basin in Malheur Gap, was in place by 32,000 years ago. There is no evidence for a diversion of the Basin outlet to Crane Gap following this event. Molluscan fossils and diatoms were used, along with soil texture analyses, to help identify and differentiate sedimentary deposits and to draw environmental inferences. Artifacts were found both on and beneath buried beach deposits of the 8680 B.P. lake. Four of the five sites in the study area were either on wave-cut terraces or other lakeshore features associated with this lake. Diagnostic artifacts are Lind Coulee points, crescents, basally ground leaf-shaped points, and what are apparently true blades. The sites seem to have been located to take advantage of shallow water littoral zone resources. Fish may have been an important dietary item of the early Harney Basin dwellers. Large salmonid vertebrae from fish in the 10 kg weight class are found on the playa. By using the relationship between landforms and elevations it may be possible to predict the general age class of other sites on the margin of the playas. Close

• 34. [Article] Origins of Late- Pleistocene Coastal Dune Sheets, Magdalena and Guerrero Negro, from Continental Shelf Low-stand Supply (70-20 ka), under Conditions of Southeast Littoral- and Eolian-Sand Transport, in Baja California Sur, Mexico

  Shallow morpho-stratigraphic sections (n = 11) in each of two large coastal dune sheets including the Magdalena (7000 km2) and Guerrero Negro (8000 km2) dune sheets, from the Pacific Ocean side of Baja ...

  Citation × Citation Citation Abstract Copy Title: Origins of Late- Pleistocene Coastal Dune Sheets, Magdalena and Guerrero Negro, from Continental Shelf Low-stand Supply (70-20 ka), under Conditions of Southeast Littoral- and Eolian-Sand Transport, in Baja California Sur, Mexico Author: Peterson, Curt D., Murillo-Jiminez, Janette, Stock, Errol, Price, David M., Hostetler, Steve W., Percy, David Year: 2017 Shallow morpho-stratigraphic sections (n = 11) in each of two large coastal dune sheets including the Magdalena (7000 km2) and Guerrero Negro (8000 km2) dune sheets, from the Pacific Ocean side of Baja California Sur, Mexico, have been analyzed for dune deposit age. The shallow morpho-stratigraphic sections (∼2-10 m depth) include 11 new TL and 14C ages, and paleosol chronosequences, that differentiate cemented late Pleistocene dune deposits (20.7 ± 2.1 to 99.8 ± 9.4 ka) from uncemented Holocene dune deposits (0.7 ± 0.05 to at least 3.2 ± 0.3 ka). Large linear dune ridges (5-10 m in height) in the dune sheet interiors trend southeast and are generally of late Pleistocene age (∼70-20 ka). The late Pleistocene dune deposits reflect eolian transport of marine sand across the emerged continental shelf (30-50 km southeast distance) from low-stand paleo-shorelines (-100 ± 25 m elevation), which were locally oriented nearly orthogonal to modeled deep-water wave directions (∼300° TN). During the Holocene marine transgression, onshore and alongshore wave transport delivered remobilized shelf-sand deposits to the nearshore areas of the large dune sheets, building extensive barrier islands and sand spits. Submerged back-barrier lagoons generally precluded marine sand supply to dune sheet interiors in middle to late Holocene time, though exceptions occur along some ocean and lagoon shorelines. Reactivation of the late Pleistocene dune deposits in the dune sheet interiors lead to generally thin (1-3 m thickness), but widespread, covers of Holocene dune deposits (0.41 ± 0.05 to 10.5 ± 1.6 ka). Mechanical drilling will be required to penetrate indurated subsoil caliche layers to reach basal Pleistocene dune deposits. Title: Origins of Late- Pleistocene Coastal Dune Sheets, Magdalena and Guerrero Negro, from Continental Shelf Low-stand Supply (70-20 ka), under Conditions of Southeast Littoral- and Eolian-Sand Transport, in Baja California Sur, Mexico Author: Peterson, Curt D., Murillo-Jiminez, Janette, Stock, Errol, Price, David M., Hostetler, Steve W., Percy, David Year: 2017 Shallow morpho-stratigraphic sections (n = 11) in each of two large coastal dune sheets including the Magdalena (7000 km2) and Guerrero Negro (8000 km2) dune sheets, from the Pacific Ocean side of Baja California Sur, Mexico, have been analyzed for dune deposit age. The shallow morpho-stratigraphic sections (∼2-10 m depth) include 11 new TL and 14C ages, and paleosol chronosequences, that differentiate cemented late Pleistocene dune deposits (20.7 ± 2.1 to 99.8 ± 9.4 ka) from uncemented Holocene dune deposits (0.7 ± 0.05 to at least 3.2 ± 0.3 ka). Large linear dune ridges (5-10 m in height) in the dune sheet interiors trend southeast and are generally of late Pleistocene age (∼70-20 ka). The late Pleistocene dune deposits reflect eolian transport of marine sand across the emerged continental shelf (30-50 km southeast distance) from low-stand paleo-shorelines (-100 ± 25 m elevation), which were locally oriented nearly orthogonal to modeled deep-water wave directions (∼300° TN). During the Holocene marine transgression, onshore and alongshore wave transport delivered remobilized shelf-sand deposits to the nearshore areas of the large dune sheets, building extensive barrier islands and sand spits. Submerged back-barrier lagoons generally precluded marine sand supply to dune sheet interiors in middle to late Holocene time, though exceptions occur along some ocean and lagoon shorelines. Reactivation of the late Pleistocene dune deposits in the dune sheet interiors lead to generally thin (1-3 m thickness), but widespread, covers of Holocene dune deposits (0.41 ± 0.05 to 10.5 ± 1.6 ka). Mechanical drilling will be required to penetrate indurated subsoil caliche layers to reach basal Pleistocene dune deposits. Close

• 35. [Article] Coastal Eolian Sand-Ramp Development Related to Paleo-Sea-Level Changes during the Latest Pleistocene and Holocene (21–0 ka) in San Miguel Island, California, U.S.A.

  Coastal eolian sand ramps (5–130 m elevation) on the northern slope (windward) side of the small San Miguel Island (13 km in W-E length) range in age from late Pleistocene to modern time, though a major ...

  Citation × Citation Citation Abstract Copy Title: Coastal Eolian Sand-Ramp Development Related to Paleo-Sea-Level Changes during the Latest Pleistocene and Holocene (21–0 ka) in San Miguel Island, California, U.S.A. Author: Peterson, Curt D., Erlandson, Jon M., Stock, Errol, Hostetler, Steve W., Price, David M. Year: 2017 Coastal eolian sand ramps (5–130 m elevation) on the northern slope (windward) side of the small San Miguel Island (13 km in W-E length) range in age from late Pleistocene to modern time, though a major hiatus in sand-ramp growth occurred during the early Holocene marine transgression (16–9 ka). The Holocene sand ramps (1–5 m measured thicknesses) currently lack large dune forms, thereby representing deflated erosional remnants, locally covering thicker late Pleistocene sand-ramp deposits. The ramp sand was initially supplied from the adjacent island-shelf platform, extending about 20 km north of the present coastline. The sand-ramp deposits and interbedded loess soils were 14C dated using 112 samples from 32 archaeological sites and other geologic sections. Latest Pleistocene sand ramps (66–18 ka) were derived from across-shelf eolian sand transport during marine low stands. Shoreward wave transport supplied remobilized late Pleistocene sand from the inner shelf to Holocene beaches, where dominant NW winds supplied sand to the sand ramps. The onset dates of the sand-ramp deposition in San Miguel are 7.2 ± 1.5 ka (sample n = 14). The internal strata dates in the vertically accreting sand ramps are 3.4 ± 1.7 ka (n = 34). The sand ramps in San Miguel show wide-scale termination of sand supply in the latest Holocene time. The sand-ramp top dates or burial dates are 1.7 ± 0.9 ka (n = 28). The latest Holocene sand ramps are truncated along most of the island's northern coastline, indicating recent losses of nearshore sand reserves to onshore, alongshore, and, possibly, offshore sand sinks. The truncated sand ramps in San Miguel Island and in other sand-depleted marine coastlines provide warnings about future beach erosion and/or shoreline retreat from accelerated sea-level rise accompanying predicted global warming. Title: Coastal Eolian Sand-Ramp Development Related to Paleo-Sea-Level Changes during the Latest Pleistocene and Holocene (21–0 ka) in San Miguel Island, California, U.S.A. Author: Peterson, Curt D., Erlandson, Jon M., Stock, Errol, Hostetler, Steve W., Price, David M. Year: 2017 Coastal eolian sand ramps (5–130 m elevation) on the northern slope (windward) side of the small San Miguel Island (13 km in W-E length) range in age from late Pleistocene to modern time, though a major hiatus in sand-ramp growth occurred during the early Holocene marine transgression (16–9 ka). The Holocene sand ramps (1–5 m measured thicknesses) currently lack large dune forms, thereby representing deflated erosional remnants, locally covering thicker late Pleistocene sand-ramp deposits. The ramp sand was initially supplied from the adjacent island-shelf platform, extending about 20 km north of the present coastline. The sand-ramp deposits and interbedded loess soils were 14C dated using 112 samples from 32 archaeological sites and other geologic sections. Latest Pleistocene sand ramps (66–18 ka) were derived from across-shelf eolian sand transport during marine low stands. Shoreward wave transport supplied remobilized late Pleistocene sand from the inner shelf to Holocene beaches, where dominant NW winds supplied sand to the sand ramps. The onset dates of the sand-ramp deposition in San Miguel are 7.2 ± 1.5 ka (sample n = 14). The internal strata dates in the vertically accreting sand ramps are 3.4 ± 1.7 ka (n = 34). The sand ramps in San Miguel show wide-scale termination of sand supply in the latest Holocene time. The sand-ramp top dates or burial dates are 1.7 ± 0.9 ka (n = 28). The latest Holocene sand ramps are truncated along most of the island's northern coastline, indicating recent losses of nearshore sand reserves to onshore, alongshore, and, possibly, offshore sand sinks. The truncated sand ramps in San Miguel Island and in other sand-depleted marine coastlines provide warnings about future beach erosion and/or shoreline retreat from accelerated sea-level rise accompanying predicted global warming. Close

• 36. [Article] A multivariate test of evolutionary stasis in Homo sapiens

  In the past, efforts to prove or disprove stasis in hominids have relied upon univariate tests such as Students's t-test. Severe methodological and interpretive problems arise from the misapplication of ...

  Citation × Citation Citation Abstract Copy Title: A multivariate test of evolutionary stasis in Homo sapiens Author: Kleckner, Jon Geoffrey Year: 1989 In the past, efforts to prove or disprove stasis in hominids have relied upon univariate tests such as Students's t-test. Severe methodological and interpretive problems arise from the misapplication of univariate statistics to questions concerning variation in shape through time. These are questions best addressed using the multivariate approach of morphometrics. Eighteen cranial dimensions drawn from 33 mid and late Pleistocene Homo sapiens were examined using principal component analysis (PCA). PCA divided the sample into two distinct morphologies. Archaic Homo sapiens of the mid Pleistocene clustered with Wurm I neanderthals and apart from post Gottweig early anatomically modern Homo sapiens. ANOVA and Cluster analysis confirm the groups represent two different morphologies rather than a single spectrum of morphological change. These results support stasis rather than phyletic gradualism during this period of hominid evolution. Title: A multivariate test of evolutionary stasis in Homo sapiens Author: Kleckner, Jon Geoffrey Year: 1989 In the past, efforts to prove or disprove stasis in hominids have relied upon univariate tests such as Students's t-test. Severe methodological and interpretive problems arise from the misapplication of univariate statistics to questions concerning variation in shape through time. These are questions best addressed using the multivariate approach of morphometrics. Eighteen cranial dimensions drawn from 33 mid and late Pleistocene Homo sapiens were examined using principal component analysis (PCA). PCA divided the sample into two distinct morphologies. Archaic Homo sapiens of the mid Pleistocene clustered with Wurm I neanderthals and apart from post Gottweig early anatomically modern Homo sapiens. ANOVA and Cluster analysis confirm the groups represent two different morphologies rather than a single spectrum of morphological change. These results support stasis rather than phyletic gradualism during this period of hominid evolution. Close

• 37. [Article] The Bear Creek Site (45KI839), a Late Pleistocene–Holocene Transition Occupation in the Puget Sound Lowland, King County, Washington

  The Bear Creek site in Redmond, Washington, yields important information about settlement, subsistence, and technology in the Puget Lowland during the late Pleistocene–Holocene transition. The lithic assemblage ...

  Citation × Citation Citation Abstract Copy Title: The Bear Creek Site (45KI839), a Late Pleistocene–Holocene Transition Occupation in the Puget Sound Lowland, King County, Washington Author: Kopperl, Robert E., Taylor, Amanda K., Miss, Christian J., Ames, Kenneth M., Hodges, Charles M. Year: 2015 The Bear Creek site in Redmond, Washington, yields important information about settlement, subsistence, and technology in the Puget Lowland during the late Pleistocene–Holocene transition. The lithic assemblage is dominated by expedient flake technology, but also contains bifaces and retouched tools. Ongoing analyses focus on site formation, procurement strategies of lithic raw materials, production of flake tools, and technological comparisons of Bear Creek stemmed and concave-base points with other Paleoarchaic technologies of western North America Title: The Bear Creek Site (45KI839), a Late Pleistocene–Holocene Transition Occupation in the Puget Sound Lowland, King County, Washington Author: Kopperl, Robert E., Taylor, Amanda K., Miss, Christian J., Ames, Kenneth M., Hodges, Charles M. Year: 2015 The Bear Creek site in Redmond, Washington, yields important information about settlement, subsistence, and technology in the Puget Lowland during the late Pleistocene–Holocene transition. The lithic assemblage is dominated by expedient flake technology, but also contains bifaces and retouched tools. Ongoing analyses focus on site formation, procurement strategies of lithic raw materials, production of flake tools, and technological comparisons of Bear Creek stemmed and concave-base points with other Paleoarchaic technologies of western North America Close

• 38. [Article] Mapping of Unstable and Potentially Unstable Slopes in Sogne og Fjordane

  For the past three years NGU has worked on 25 unstable and potentially unstable rock slopes in Sogn og Fjordane. In addition Fjærlandsfjord, Hyenfjord and Årdalsvatnet were systematically mapped for deposits ...

  Citation × Citation Citation Abstract Copy Title: Mapping of Unstable and Potentially Unstable Slopes in Sogne og Fjordane Author: Hermanns, Reginald L., Fischer, Luzia, Oppikofer, Thierry, Bøhme, M., Dehls, John F., Henriksen, H., Booth, Adam M., Eilertsen, R., Longva, O., Eiken, Trond Year: 2011 For the past three years NGU has worked on 25 unstable and potentially unstable rock slopes in Sogn og Fjordane. In addition Fjærlandsfjord, Hyenfjord and Årdalsvatnet were systematically mapped for deposits of prehistoric and historic rock slope failures onshore and with help of a bathymetry. Mapping on land included structural mapping of ten sites by on-site field mapping and nine sites by remote structural mapping using terrestrial laser scanning technology (TLS). Field work also included periodic monitoring of 14 sites using differential Global Positioning Systems (dGPS) and TLS at 4 sites. Synthetic Aperture Radar was app lied for the entire county but slide velocities could only be mapped out at one locality at Osmundneset (Gloppen municipality). A large amount of work was carried out on the slope east of Flåm in the Aurland valley, and results have been reported separately (NGU 20 11 .025). Three large instabilities have been discovered or taken into the monitoring program. These are Osmundneset in Gloppen municipality, Skrednipa in Sogndal municipality, and the Ovris valley in Vik municipality. The largest movements with 1.5 cm horizontal and 1.5 cm vertical displacement were measured on the instability with a volume of approx. 1 Mm3 in Ovris valley. Opening of cracks has been measured at that site also in the 1960’s, 1970’s and 1980’s. Our data suggest a slight acceleration of this instability. Acceleration was also documented for a 100.000 m3 large instability called Lifjellet, although velocity of that site is less than half of the velocity of the block in Ovris valley. However at that site a collapse of a rockslope with a volume of 25.000 to 30.000 m3 occurred only 19 years ago. Installation of continuous monitoring and early-warning systems should be considered at both of those sites as well as at similar sites where relatively small instabilities that might fail without a long acceleration phase are positioned above settlements (Gråberget in Høyanger municipality). Similarly all other monitored instabilities in Sogn og Fjordane are in the order of mm/yr and not considered to be critical on a short term. However, periodic monitoring has to be continued. Cosmogenic nuclide dating (CN) has been applied to determine ages of rockslide deposits in Fjærlandfjord (Sogne municipality) and at the slope E of Flåm (Aurland community), resulting in Late Pleistocene and Holocene ages. CN dating has also applied to the sliding planes at Skjeringahaugane (Luste municipality). The results indicate that the movement initiated at the beginning of the Holocene and is progressive. Long term slip rates are in the same order of slip rates measured by dGPS. Title: Mapping of Unstable and Potentially Unstable Slopes in Sogne og Fjordane Author: Hermanns, Reginald L., Fischer, Luzia, Oppikofer, Thierry, Bøhme, M., Dehls, John F., Henriksen, H., Booth, Adam M., Eilertsen, R., Longva, O., Eiken, Trond Year: 2011 For the past three years NGU has worked on 25 unstable and potentially unstable rock slopes in Sogn og Fjordane. In addition Fjærlandsfjord, Hyenfjord and Årdalsvatnet were systematically mapped for deposits of prehistoric and historic rock slope failures onshore and with help of a bathymetry. Mapping on land included structural mapping of ten sites by on-site field mapping and nine sites by remote structural mapping using terrestrial laser scanning technology (TLS). Field work also included periodic monitoring of 14 sites using differential Global Positioning Systems (dGPS) and TLS at 4 sites. Synthetic Aperture Radar was app lied for the entire county but slide velocities could only be mapped out at one locality at Osmundneset (Gloppen municipality). A large amount of work was carried out on the slope east of Flåm in the Aurland valley, and results have been reported separately (NGU 20 11 .025). Three large instabilities have been discovered or taken into the monitoring program. These are Osmundneset in Gloppen municipality, Skrednipa in Sogndal municipality, and the Ovris valley in Vik municipality. The largest movements with 1.5 cm horizontal and 1.5 cm vertical displacement were measured on the instability with a volume of approx. 1 Mm3 in Ovris valley. Opening of cracks has been measured at that site also in the 1960’s, 1970’s and 1980’s. Our data suggest a slight acceleration of this instability. Acceleration was also documented for a 100.000 m3 large instability called Lifjellet, although velocity of that site is less than half of the velocity of the block in Ovris valley. However at that site a collapse of a rockslope with a volume of 25.000 to 30.000 m3 occurred only 19 years ago. Installation of continuous monitoring and early-warning systems should be considered at both of those sites as well as at similar sites where relatively small instabilities that might fail without a long acceleration phase are positioned above settlements (Gråberget in Høyanger municipality). Similarly all other monitored instabilities in Sogn og Fjordane are in the order of mm/yr and not considered to be critical on a short term. However, periodic monitoring has to be continued. Cosmogenic nuclide dating (CN) has been applied to determine ages of rockslide deposits in Fjærlandfjord (Sogne municipality) and at the slope E of Flåm (Aurland community), resulting in Late Pleistocene and Holocene ages. CN dating has also applied to the sliding planes at Skjeringahaugane (Luste municipality). The results indicate that the movement initiated at the beginning of the Holocene and is progressive. Long term slip rates are in the same order of slip rates measured by dGPS. Close

• 39. [Article] Late Pleistocene and Holocene Aged Glacial and Climatic Reconstructions in the Goat Rocks Wilderness, Washington, United States

  Eight glaciers, covering an area of 1.63 km2, reside on the northern and northeastern slopes of the Goat Rocks tallest peaks in the Cascades of central Washington. At least three glacial stands occurred ...

  Citation × Citation Citation Abstract Copy Title: Late Pleistocene and Holocene Aged Glacial and Climatic Reconstructions in the Goat Rocks Wilderness, Washington, United States Author: Heard, Joshua Andrews Year: 2012 Eight glaciers, covering an area of 1.63 km2, reside on the northern and northeastern slopes of the Goat Rocks tallest peaks in the Cascades of central Washington. At least three glacial stands occurred downstream from these glaciers. Closest to modern glacier termini are Little Ice Age (LIA) moraines that were deposited between 1870 and 1899 AD, according to the lichenometric analysis. They are characterized by sharp, minimally eroded crests, little to no soil cover, and minimal vegetation cover. Glacier reconstructions indicate that LIA glaciers covered 8.29 km2, 76% more area than modern ice coverage. The average LIA equilibrium line altitude (ELA) of 1995 ± 70 m is ~150 m below the average modern ELA of 2149 ± 76 m. To satisfy climate conditions at the LIA ELA, the winter snow accumulation must have been 8 to 43 cm greater and mean summer temperatures 0.2 to 1.3 ºC cooler than they are now. Late Pleistocene to early Holocene (LPEH) aged moraines are located between 100 and 400 m below the LIA deposits. They have degraded moraine crests, few surface boulders, and considerable vegetation and soil cover. Volcanic ashes indicate LPEH moraines were deposited before 1480 AD while morphometric data suggest deposition during the late Pleistocene or early Holocene. The average LPEH ELA of 1904 ± 110 m is ~ 240 m and ~90 m below the modern and LIA ELAs, respectively. The climate change necessary to maintain a glacier with an ELA at that elevation for LPEH conditions requires the winter accumulation to increase by 47 to 48 cm weq and the mean summer temperature to cool by 1.4 to 1.5 ºC. Last glacial maximum (LGM) moraines are located more than 30 km downstream from modern glacial termini. They are characterized by hummocky topography, rounded moraine crests, complete vegetation cover, and well developed soil cover. Moraine morphometry, soil characteristics, and distance from modern glacial termini indicate that deposition occurred at least 15 ka BP during an expansive cooling event, the last being the LGM. The LGM ELA of 1230 m is ~920 m below the modern ELA. The climate change necessary to maintain a glacier with an ELA at that elevation for LGM conditions requires the mean summer temperature to cool by 5.6 ºC with no change in precipitation. Title: Late Pleistocene and Holocene Aged Glacial and Climatic Reconstructions in the Goat Rocks Wilderness, Washington, United States Author: Heard, Joshua Andrews Year: 2012 Eight glaciers, covering an area of 1.63 km2, reside on the northern and northeastern slopes of the Goat Rocks tallest peaks in the Cascades of central Washington. At least three glacial stands occurred downstream from these glaciers. Closest to modern glacier termini are Little Ice Age (LIA) moraines that were deposited between 1870 and 1899 AD, according to the lichenometric analysis. They are characterized by sharp, minimally eroded crests, little to no soil cover, and minimal vegetation cover. Glacier reconstructions indicate that LIA glaciers covered 8.29 km2, 76% more area than modern ice coverage. The average LIA equilibrium line altitude (ELA) of 1995 ± 70 m is ~150 m below the average modern ELA of 2149 ± 76 m. To satisfy climate conditions at the LIA ELA, the winter snow accumulation must have been 8 to 43 cm greater and mean summer temperatures 0.2 to 1.3 ºC cooler than they are now. Late Pleistocene to early Holocene (LPEH) aged moraines are located between 100 and 400 m below the LIA deposits. They have degraded moraine crests, few surface boulders, and considerable vegetation and soil cover. Volcanic ashes indicate LPEH moraines were deposited before 1480 AD while morphometric data suggest deposition during the late Pleistocene or early Holocene. The average LPEH ELA of 1904 ± 110 m is ~ 240 m and ~90 m below the modern and LIA ELAs, respectively. The climate change necessary to maintain a glacier with an ELA at that elevation for LPEH conditions requires the winter accumulation to increase by 47 to 48 cm weq and the mean summer temperature to cool by 1.4 to 1.5 ºC. Last glacial maximum (LGM) moraines are located more than 30 km downstream from modern glacial termini. They are characterized by hummocky topography, rounded moraine crests, complete vegetation cover, and well developed soil cover. Moraine morphometry, soil characteristics, and distance from modern glacial termini indicate that deposition occurred at least 15 ka BP during an expansive cooling event, the last being the LGM. The LGM ELA of 1230 m is ~920 m below the modern ELA. The climate change necessary to maintain a glacier with an ELA at that elevation for LGM conditions requires the mean summer temperature to cool by 5.6 ºC with no change in precipitation. Close

• 40. [Article] Biochemical Description of a Lava Tube Lake in Southeast Oregon

  A Pleistocene lava tube cave in southeast Oregon has a seasonally fluctuating lake occupying the last 1200 to 2000 feet. Three endemic invertebrate species inhabit the lake: Kenkia rynchida Hyman; Asellus ...

  Citation × Citation Citation Abstract Copy Title: Biochemical Description of a Lava Tube Lake in Southeast Oregon Author: Palmer, John Edward Year: 1975 A Pleistocene lava tube cave in southeast Oregon has a seasonally fluctuating lake occupying the last 1200 to 2000 feet. Three endemic invertebrate species inhabit the lake: Kenkia rynchida Hyman; Asellus sp.; and stygobromus hubbsi. Shoemaker. Little is known however, about their environment. The purpose of this study was to describe various physical and chemical parameters of Malheur Cave Lake. Title: Biochemical Description of a Lava Tube Lake in Southeast Oregon Author: Palmer, John Edward Year: 1975 A Pleistocene lava tube cave in southeast Oregon has a seasonally fluctuating lake occupying the last 1200 to 2000 feet. Three endemic invertebrate species inhabit the lake: Kenkia rynchida Hyman; Asellus sp.; and stygobromus hubbsi. Shoemaker. Little is known however, about their environment. The purpose of this study was to describe various physical and chemical parameters of Malheur Cave Lake. Close

• 41. [Article] Chronology and Ecology of Late Pleistocene Megafauna in the Northern Willamette Valley, Oregon

  This study is an investigation of the timing of extinction of late Pleistocene, large bodied mammalian herbivores (megafauna) and of the environment in which they lived. The demise of the megafauna near ...

  Citation × Citation Citation Abstract Copy Title: Chronology and Ecology of Late Pleistocene Megafauna in the Northern Willamette Valley, Oregon Author: Gilmour, Daniel McGowan Year: 2011 This study is an investigation of the timing of extinction of late Pleistocene, large bodied mammalian herbivores (megafauna) and of the environment in which they lived. The demise of the megafauna near the end of the Pleistocene remains unexplained. Owing to potential human involvement in the extinctions, archaeologists have been particularly concerned to understand the causes for faunal losses. Our current lack of understanding of the timing and the causes of the extinctions in North America may result from a deficiency in understanding the histories of each individual species of extinct animal on a local level. Detailed regional chronologies of fauna are necessary for comparison with paleoenvironmental and archaeological data to help sort out causes for extinction. The Willamette Valley of western Oregon has long been noted for finds of megafauna, though records have not been synthesized since the early 20th century and these materials have remained largely unstudied. In this thesis, I first create a catalog of extinct megafauna recovered from the Willamette Valley. Next, using material from the northern valley, I employ AMS radiocarbon dating, stable isotope δ¹³C and δ¹⁵N analyses, and gross inferences based on the dietary specializations and habitat preferences of taxa in order to reconstruct environments and to develop a local chronology of events that is then arrayed against archaeological and paleoenvironmental data. The results of this study indicate that megafaunal populations in the northern Willamette Valley were contemporaneous with the earliest known human populations of the Pacific Northwest, as well as later populations associated with the Clovis Paleoindian Horizon. Consistent with the overkill hypothesis, radiocarbon ages span the length of the Clovis window, but no ages are younger than Clovis. Moreover, all radiocarbon ages are older than or contemporaneous to the onset of the Younger Dryas Stadial. No age ranges fall exclusively within the Younger Dryas. Comparison of megafaunal ages and paleoenvironmental records support the view that climate change contributed to local animal population declines. Prior to ~13,000 cal BP, the Willamette Valley was an open environment; herbivores mainly consumed C₃ vegetation. The timing of the loss of megafauna coincides with increased forested conditions as indicated by regional paleoenvironmental reconstruction. As the timing of megafaunal decline correlates with Clovis, the onset of the Younger Dryas, and increased forested conditions, it is not possible with the data currently available to distinguish the cause of extinction in the Willamette Valley. The age ranges of the fauna coupled with taphonomic and geologic context indicate that the fauna are autochthonous to the Willamette Valley; they do not represent ice rafted carcasses or isolated skeletal elements transported from elsewhere during late Pleistocene glacial outburst floods. Title: Chronology and Ecology of Late Pleistocene Megafauna in the Northern Willamette Valley, Oregon Author: Gilmour, Daniel McGowan Year: 2011 This study is an investigation of the timing of extinction of late Pleistocene, large bodied mammalian herbivores (megafauna) and of the environment in which they lived. The demise of the megafauna near the end of the Pleistocene remains unexplained. Owing to potential human involvement in the extinctions, archaeologists have been particularly concerned to understand the causes for faunal losses. Our current lack of understanding of the timing and the causes of the extinctions in North America may result from a deficiency in understanding the histories of each individual species of extinct animal on a local level. Detailed regional chronologies of fauna are necessary for comparison with paleoenvironmental and archaeological data to help sort out causes for extinction. The Willamette Valley of western Oregon has long been noted for finds of megafauna, though records have not been synthesized since the early 20th century and these materials have remained largely unstudied. In this thesis, I first create a catalog of extinct megafauna recovered from the Willamette Valley. Next, using material from the northern valley, I employ AMS radiocarbon dating, stable isotope δ¹³C and δ¹⁵N analyses, and gross inferences based on the dietary specializations and habitat preferences of taxa in order to reconstruct environments and to develop a local chronology of events that is then arrayed against archaeological and paleoenvironmental data. The results of this study indicate that megafaunal populations in the northern Willamette Valley were contemporaneous with the earliest known human populations of the Pacific Northwest, as well as later populations associated with the Clovis Paleoindian Horizon. Consistent with the overkill hypothesis, radiocarbon ages span the length of the Clovis window, but no ages are younger than Clovis. Moreover, all radiocarbon ages are older than or contemporaneous to the onset of the Younger Dryas Stadial. No age ranges fall exclusively within the Younger Dryas. Comparison of megafaunal ages and paleoenvironmental records support the view that climate change contributed to local animal population declines. Prior to ~13,000 cal BP, the Willamette Valley was an open environment; herbivores mainly consumed C₃ vegetation. The timing of the loss of megafauna coincides with increased forested conditions as indicated by regional paleoenvironmental reconstruction. As the timing of megafaunal decline correlates with Clovis, the onset of the Younger Dryas, and increased forested conditions, it is not possible with the data currently available to distinguish the cause of extinction in the Willamette Valley. The age ranges of the fauna coupled with taphonomic and geologic context indicate that the fauna are autochthonous to the Willamette Valley; they do not represent ice rafted carcasses or isolated skeletal elements transported from elsewhere during late Pleistocene glacial outburst floods. Close

• 42. [Article] Hydrogeologic Investigation of the Klamath Marsh, Klamath County, Oregon

  Klamath Marsh is a wetland complex that lies in the rain shadow of the Cascade Range in the Williamson River sub-basin of the Klamath Basin. The marsh lies directly east of Crater Lake in an area inundated ...

  Citation × Citation Citation Abstract Copy Title: Hydrogeologic Investigation of the Klamath Marsh, Klamath County, Oregon Author: Melady, Jason Michael Year: 2002 Klamath Marsh is a wetland complex that lies in the rain shadow of the Cascade Range in the Williamson River sub-basin of the Klamath Basin. The marsh lies directly east of Crater Lake in an area inundated by pyroclastic-flow and -fall deposits from the Holocene eruptions of Mount Mazama. The physical characteristics of rocks of Pleistocene versus Pliocene age combined with NNW -striking fault systems divide the Williamson River basin into two distinct hydrogeologic regimes. The northwestern regime includes the east slope of the Cascades and consists of at least 150 m of interbedded sand, gravel, and stacks (15 to 45 m) of thin (3-5 m) and vesiculated basalt lava flows. Mean annual precipitation ranges from 150 cm near the crest of the Cascades to 50 cm near Klamath Marsh. Moderate to high yield (100 to 4000 gpm) water wells, springs and flowing wells suggest high permeability and ground water potential. The southeastern regime is underlain by Pliocene pyroclastic flows (∼ 40 m) and lava flows (>30 m). Mean annual precipitation ranges from 70 cm in the highlands to 50 cm in the lowlands. Low-yield (20-100 gpm) water wells and perched unconfined aquifers in Holocene pumice deposits suggest low permeability and low ground water potential in areas underlain by the pyroclastic flows. Volumetric analysis of inflows and outflows in Klamath Marsh for 2000 indicates approximately 86% of inflow is from groundwater and 14% from surface water, with nearly 200 x 10⁶ m³ of water removed by evapotranspiration Title: Hydrogeologic Investigation of the Klamath Marsh, Klamath County, Oregon Author: Melady, Jason Michael Year: 2002 Klamath Marsh is a wetland complex that lies in the rain shadow of the Cascade Range in the Williamson River sub-basin of the Klamath Basin. The marsh lies directly east of Crater Lake in an area inundated by pyroclastic-flow and -fall deposits from the Holocene eruptions of Mount Mazama. The physical characteristics of rocks of Pleistocene versus Pliocene age combined with NNW -striking fault systems divide the Williamson River basin into two distinct hydrogeologic regimes. The northwestern regime includes the east slope of the Cascades and consists of at least 150 m of interbedded sand, gravel, and stacks (15 to 45 m) of thin (3-5 m) and vesiculated basalt lava flows. Mean annual precipitation ranges from 150 cm near the crest of the Cascades to 50 cm near Klamath Marsh. Moderate to high yield (100 to 4000 gpm) water wells, springs and flowing wells suggest high permeability and ground water potential. The southeastern regime is underlain by Pliocene pyroclastic flows (∼ 40 m) and lava flows (>30 m). Mean annual precipitation ranges from 70 cm in the highlands to 50 cm in the lowlands. Low-yield (20-100 gpm) water wells and perched unconfined aquifers in Holocene pumice deposits suggest low permeability and low ground water potential in areas underlain by the pyroclastic flows. Volumetric analysis of inflows and outflows in Klamath Marsh for 2000 indicates approximately 86% of inflow is from groundwater and 14% from surface water, with nearly 200 x 10⁶ m³ of water removed by evapotranspiration Close

• 43. [Article] Chronology and Ecology of Late Pleistocene Megafauna in the Northern Willamette Valley, Oregon

  Since the mid-19th century, western Oregon's Willamette Valley has been a source of remains from a wide variety of extinct megafauna. Few of these have been previously described or dated, but new chronologic ...

  Citation × Citation Citation Abstract Copy Title: Chronology and Ecology of Late Pleistocene Megafauna in the Northern Willamette Valley, Oregon Author: Gilmour, Daniel McGowan, Butler, Virginia L., O'Conner, Jim E., Byrd Davis, Edward, Culleton, Brendan J., Kennett, Douglas J., Hodgins, Gregory Year: 2014 Since the mid-19th century, western Oregon's Willamette Valley has been a source of remains from a wide variety of extinct megafauna. Few of these have been previously described or dated, but new chronologic and isotopic analyses in conjunction with updated evaluations of stratigraphic context provide substantial new information on the species present, timing of losses, and paleoenvironmental conditions. Using subfossil material from the northern valley, we use AMS radiocarbon dating, stable isotope (δ13C and δ15N) analyses, and taxonomic dietary specialization and habitat preferences to reconstruct environments and to develop a local chronology of events that we then compare with continental and regional archaeological and paleoenvironmental data. Analysis of twelve bone specimens demonstrates the presence of bison, mammoth, horse, sloth, and mastodon from ~15,000–13,000 cal yr BP. The latest ages coincide with changing regional climate corresponding to the onset of the Younger Dryas. It is suggested that cooling conditions led to increased forest cover, and, along with river aggradation, reduced the area of preferred habitat for the larger bodied herbivores, which contributed to the demise of local megafauna. Archaeological evidence for megafauna–human interactions in the Pacific Northwest is scarce, limiting our ability to address the human role in causing extinction. Title: Chronology and Ecology of Late Pleistocene Megafauna in the Northern Willamette Valley, Oregon Author: Gilmour, Daniel McGowan, Butler, Virginia L., O'Conner, Jim E., Byrd Davis, Edward, Culleton, Brendan J., Kennett, Douglas J., Hodgins, Gregory Year: 2014 Since the mid-19th century, western Oregon's Willamette Valley has been a source of remains from a wide variety of extinct megafauna. Few of these have been previously described or dated, but new chronologic and isotopic analyses in conjunction with updated evaluations of stratigraphic context provide substantial new information on the species present, timing of losses, and paleoenvironmental conditions. Using subfossil material from the northern valley, we use AMS radiocarbon dating, stable isotope (δ13C and δ15N) analyses, and taxonomic dietary specialization and habitat preferences to reconstruct environments and to develop a local chronology of events that we then compare with continental and regional archaeological and paleoenvironmental data. Analysis of twelve bone specimens demonstrates the presence of bison, mammoth, horse, sloth, and mastodon from ~15,000–13,000 cal yr BP. The latest ages coincide with changing regional climate corresponding to the onset of the Younger Dryas. It is suggested that cooling conditions led to increased forest cover, and, along with river aggradation, reduced the area of preferred habitat for the larger bodied herbivores, which contributed to the demise of local megafauna. Archaeological evidence for megafauna–human interactions in the Pacific Northwest is scarce, limiting our ability to address the human role in causing extinction. Close

• 44. [Article] A Characterization of Lake Abert Tufa Mounds Lake Abert, Oregon

  A series of tufa mounds is found within the northern basin of Lake Abert, located within southeastern Oregon. The mounds have been divided into 3 main groups and 1 sub-group (A1, A2, B, and C) based upon ...

  Citation × Citation Citation Abstract Copy Title: A Characterization of Lake Abert Tufa Mounds Lake Abert, Oregon Author: Bartruff, Anthony Lynn Year: 2013 A series of tufa mounds is found within the northern basin of Lake Abert, located within southeastern Oregon. The mounds have been divided into 3 main groups and 1 sub-group (A1, A2, B, and C) based upon spatial and textural considerations. Mound groups appear at two different elevations: the 1310 meter elevation (Groups A2, B, and C), and the 1318 meter elevation (Group A1). Published carbon age dating of the Lake Abert 1325 meter strandline and the 1310 meter strandline indicates that the mounds were formed during the Late Pleistocene/Early Holocene. Facies analysis and mineralogical analysis of the mounds indicates that the mounds were primarily formed subaqueously during a lake regression, supporting oxygen isotope data from previous researchers. Magnetometer data within Groups A1 and A2 suggests that the mounds are associated with a series of magnetic lows which are oriented in joint sets (NW-SE, and N-S) which match the orientation of faulting within the region. While there appears to be another early mound building episode, no direct evidence confirms this. Title: A Characterization of Lake Abert Tufa Mounds Lake Abert, Oregon Author: Bartruff, Anthony Lynn Year: 2013 A series of tufa mounds is found within the northern basin of Lake Abert, located within southeastern Oregon. The mounds have been divided into 3 main groups and 1 sub-group (A1, A2, B, and C) based upon spatial and textural considerations. Mound groups appear at two different elevations: the 1310 meter elevation (Groups A2, B, and C), and the 1318 meter elevation (Group A1). Published carbon age dating of the Lake Abert 1325 meter strandline and the 1310 meter strandline indicates that the mounds were formed during the Late Pleistocene/Early Holocene. Facies analysis and mineralogical analysis of the mounds indicates that the mounds were primarily formed subaqueously during a lake regression, supporting oxygen isotope data from previous researchers. Magnetometer data within Groups A1 and A2 suggests that the mounds are associated with a series of magnetic lows which are oriented in joint sets (NW-SE, and N-S) which match the orientation of faulting within the region. While there appears to be another early mound building episode, no direct evidence confirms this. Close

• 45. [Article] Ancient Cataclysmic Floods in the Pacific Northwest: Ancestors to the Missoula Floods

  Ancient Cataclysmic Floods were the Ice Age Floods that left erosional and depositional features and preceded the Missoula Floods (15-18,000 ka) in the Pacific Northwest of the United States (Allen et ...

  Citation × Citation Citation Abstract Copy Title: Ancient Cataclysmic Floods in the Pacific Northwest: Ancestors to the Missoula Floods Author: Medley, Erica Year: 2012 Ancient Cataclysmic Floods were the Ice Age Floods that left erosional and depositional features and preceded the Missoula Floods (15-18,000 ka) in the Pacific Northwest of the United States (Allen et al., 2009). All previously studied ancient sites were visited (14) and new sites (11) were found; four Missoula Flood quarries were also visited; a total of 29 sites were studied in this thesis. The use of calcrete paleosols to provide relative age dates for flood deposits was analyzed in this thesis. Missoula Flood gravel pits were sampled in order to examine the degree of calcrete development in flood deposits of known ages. All of the Missoula Flood deposits tested contain Stage 1 calcrete soil development. Calcrete paleosols at sites with evidence for older floods were all analyzed. Eight sites have paleosols with Stage II development (3-12% CaCO3): Rulo Outcrop, Potholes Coulee, Leslie Road, Benge, E. Callaway Road, Collier Coulee, Palouse, and Connell. Five sites have paleosols with Stage II+ development (12-17% CaCO3): Brown Road, Leslie Road, Benge, Reese Coulee, and Connell. Fourteen sites have paleosols with Stage III development (17-35% CaCO3): The Dalles, Rulo Outcrop, Winans Road 1, Poplar Heights, Yakima Bluffs, Canal Outcrop, Othello Canal, Reese Coulee, Potholes Coulee, E. Callaway Road, Frenchmen Coulee, Macall, Ritzville, and East Connell. One site has a paleosol with Stage III+ development (35-50% CaCO3): Othello Canal. Ancient Cataclysmic flooding initiated in the Early Pleistocene, at least 1.5 Ma. Sixteen field sites show evidence for Early Pleistocene flooding, preserved in all six provinces: Othello Channels, Columbia River Gorge, Cheney-Palouse Scabland, Quincy Basin, Pasco Basin, and the Walla Walla Valley. There are 26 field sites with evidence for Middle Pleistocene flooding, present in all regions except Othello Channels. Eleven of those 26 sites also show evidence for Early Pleistocene floods. Evidence for Early and Middle Pleistocene floods is present over a wide distribution of elevations from 117 to 524 meters. Title: Ancient Cataclysmic Floods in the Pacific Northwest: Ancestors to the Missoula Floods Author: Medley, Erica Year: 2012 Ancient Cataclysmic Floods were the Ice Age Floods that left erosional and depositional features and preceded the Missoula Floods (15-18,000 ka) in the Pacific Northwest of the United States (Allen et al., 2009). All previously studied ancient sites were visited (14) and new sites (11) were found; four Missoula Flood quarries were also visited; a total of 29 sites were studied in this thesis. The use of calcrete paleosols to provide relative age dates for flood deposits was analyzed in this thesis. Missoula Flood gravel pits were sampled in order to examine the degree of calcrete development in flood deposits of known ages. All of the Missoula Flood deposits tested contain Stage 1 calcrete soil development. Calcrete paleosols at sites with evidence for older floods were all analyzed. Eight sites have paleosols with Stage II development (3-12% CaCO3): Rulo Outcrop, Potholes Coulee, Leslie Road, Benge, E. Callaway Road, Collier Coulee, Palouse, and Connell. Five sites have paleosols with Stage II+ development (12-17% CaCO3): Brown Road, Leslie Road, Benge, Reese Coulee, and Connell. Fourteen sites have paleosols with Stage III development (17-35% CaCO3): The Dalles, Rulo Outcrop, Winans Road 1, Poplar Heights, Yakima Bluffs, Canal Outcrop, Othello Canal, Reese Coulee, Potholes Coulee, E. Callaway Road, Frenchmen Coulee, Macall, Ritzville, and East Connell. One site has a paleosol with Stage III+ development (35-50% CaCO3): Othello Canal. Ancient Cataclysmic flooding initiated in the Early Pleistocene, at least 1.5 Ma. Sixteen field sites show evidence for Early Pleistocene flooding, preserved in all six provinces: Othello Channels, Columbia River Gorge, Cheney-Palouse Scabland, Quincy Basin, Pasco Basin, and the Walla Walla Valley. There are 26 field sites with evidence for Middle Pleistocene flooding, present in all regions except Othello Channels. Eleven of those 26 sites also show evidence for Early Pleistocene floods. Evidence for Early and Middle Pleistocene floods is present over a wide distribution of elevations from 117 to 524 meters. Close

• 46. [Article] Accommodation Space Controls on the Latest Pleistocene and Holocene (16–0 ka) Sediment Size and Bypassing in the Lower Columbia River Valley: A Large Fluvial–Tidal System in Oregon and Washington, USA

  In this study, we establish the roles that increasing basin accommodation space have on sediment size and bypassing in the transgressive fill (16–0 ka) in the submerged Lower Columbia River Valley (LCRV). ...

  Citation × Citation Citation Abstract Copy Title: Accommodation Space Controls on the Latest Pleistocene and Holocene (16–0 ka) Sediment Size and Bypassing in the Lower Columbia River Valley: A Large Fluvial–Tidal System in Oregon and Washington, USA Author: Peterson, Curt D. Year: 2013 In this study, we establish the roles that increasing basin accommodation space have on sediment size and bypassing in the transgressive fill (16–0 ka) in the submerged Lower Columbia River Valley (LCRV). The antecedent forearc valley (225 km in length, 4–8 km in width, and 60–115 m in axial valley depth) is characterized by high sediment supply rates (10–15 million t y-1) but no delta at its mouth to the Pacific Ocean. Core sample sediment textures (N ¼ 1600) are analyzed from 3000 m of borehole sections in 58 representative boreholes to characterize the ancestral valley fill: 57% sand, 17% muddy sand, 12% sandy mud, and 14% mud (total fill volume¼77 km3). Decreasing mud endmember texture from between 30 and 60% (early Holocene) to 18% (late Holocene) is directly related to (1) declining rates of increasing basin accommodation space and (2) increasing sediment bypassing through the LCRV. Both conditions result from decreasing rates of sea level rise (15.0–1.5 mm y-1) in Holocene time. The overall coarsening of sediments, both upvalley and upsection, is controlled by declining rates of increasing basin accommodation space (5.66 million–0.57 million m3 y-1) during middle to late Holocene time. Differences between middle and late Holocene sediment accumulation rates yield bedload bypassing rates of 5– 6 million m3 y-1, under assumed conditions of constant sediment supply rates in middle to late Holocene time. Title: Accommodation Space Controls on the Latest Pleistocene and Holocene (16–0 ka) Sediment Size and Bypassing in the Lower Columbia River Valley: A Large Fluvial–Tidal System in Oregon and Washington, USA Author: Peterson, Curt D. Year: 2013 In this study, we establish the roles that increasing basin accommodation space have on sediment size and bypassing in the transgressive fill (16–0 ka) in the submerged Lower Columbia River Valley (LCRV). The antecedent forearc valley (225 km in length, 4–8 km in width, and 60–115 m in axial valley depth) is characterized by high sediment supply rates (10–15 million t y-1) but no delta at its mouth to the Pacific Ocean. Core sample sediment textures (N ¼ 1600) are analyzed from 3000 m of borehole sections in 58 representative boreholes to characterize the ancestral valley fill: 57% sand, 17% muddy sand, 12% sandy mud, and 14% mud (total fill volume¼77 km3). Decreasing mud endmember texture from between 30 and 60% (early Holocene) to 18% (late Holocene) is directly related to (1) declining rates of increasing basin accommodation space and (2) increasing sediment bypassing through the LCRV. Both conditions result from decreasing rates of sea level rise (15.0–1.5 mm y-1) in Holocene time. The overall coarsening of sediments, both upvalley and upsection, is controlled by declining rates of increasing basin accommodation space (5.66 million–0.57 million m3 y-1) during middle to late Holocene time. Differences between middle and late Holocene sediment accumulation rates yield bedload bypassing rates of 5– 6 million m3 y-1, under assumed conditions of constant sediment supply rates in middle to late Holocene time. Close

• 47. [Article] Groundwater Surface Trends in the North Florence Dunal Aquifer, Oregon Coast, USA

  The North Florence Dunal Aquifer is the only feasible source for drinking water for the coastal city of Florence, Oregon and Florence's Urban Growth Boundary. High infiltration rates and a shallow groundwater ...

  Citation × Citation Citation Abstract Copy Title: Groundwater Surface Trends in the North Florence Dunal Aquifer, Oregon Coast, USA Author: Doliber, Sarah Rebecca Year: 2012 The North Florence Dunal Aquifer is the only feasible source for drinking water for the coastal city of Florence, Oregon and Florence's Urban Growth Boundary. High infiltration rates and a shallow groundwater table leave the aquifer highly susceptible to contamination from septic tank effluent, storm runoff, chemical fertilizers and recreational ATV use throughout the dunes. Public interest in the quality and quantity of the aquifer water has been sparked since the City of Florence received a grant from the Environmental Protection Agency for a watershed protection and restoration project. Delineation of the shallow groundwater surface and its relationship to the surface water bodies within the dunes is crucial in protecting this drinking water source from contamination. This thesis project created a GIS representation of the shallow groundwater elevation and associated prediction error map. Surface water bodies were confirmed as window lakes into the dunal aquifer and no signs of perched aquifer conditions were observed between Holocene and Pleistocene dunes. Ground Penetrating Radar, well data provided by the city of Florence and LiDAR were the primary sources for data collection. Title: Groundwater Surface Trends in the North Florence Dunal Aquifer, Oregon Coast, USA Author: Doliber, Sarah Rebecca Year: 2012 The North Florence Dunal Aquifer is the only feasible source for drinking water for the coastal city of Florence, Oregon and Florence's Urban Growth Boundary. High infiltration rates and a shallow groundwater table leave the aquifer highly susceptible to contamination from septic tank effluent, storm runoff, chemical fertilizers and recreational ATV use throughout the dunes. Public interest in the quality and quantity of the aquifer water has been sparked since the City of Florence received a grant from the Environmental Protection Agency for a watershed protection and restoration project. Delineation of the shallow groundwater surface and its relationship to the surface water bodies within the dunes is crucial in protecting this drinking water source from contamination. This thesis project created a GIS representation of the shallow groundwater elevation and associated prediction error map. Surface water bodies were confirmed as window lakes into the dunal aquifer and no signs of perched aquifer conditions were observed between Holocene and Pleistocene dunes. Ground Penetrating Radar, well data provided by the city of Florence and LiDAR were the primary sources for data collection. Close

• 48. [Article] Origins of Quaternary Coastal Dune Sheets in San Francisco and Monterey Bay, Central California Coast, U.S.A.: Reflecting Contrasts in Shelf Depocenters and Coastal Neotectonics

  The San Francisco and Monterey Bay coastal dune sheets derive from similar origins in the central California coast but differ substantially in size (respectively, ~400 and ~900 km2) and age (respectively, ...

  Citation × Citation Citation Abstract Copy Title: Origins of Quaternary Coastal Dune Sheets in San Francisco and Monterey Bay, Central California Coast, U.S.A.: Reflecting Contrasts in Shelf Depocenters and Coastal Neotectonics Author: Peterson, Curt D., Stock, Errol, Meyer, Jack, Kaijankoski, Philip, Price, David M. Year: 2015 The San Francisco and Monterey Bay coastal dune sheets derive from similar origins in the central California coast but differ substantially in size (respectively, ~400 and ~900 km2) and age (respectively, 1.0 Ma). The San Francisco dune sheet is restricted to a short alongshore interval (km) within a relatively straight coastline (150 km in length) that borders a broad shelf (~40 km in width). The Monterey Bay dune sheet is restricted to the Monterey Bay embayment (41 km alongshore length). The embayment includes a very narrow shelf (3–15 km in width), which is dissected by the Monterey Submarine Canyon. Generally low onshore topographic relief (elevation) likely enhanced inland transgression of Late Pleistocene dune fields in both the San Francisco and Monterey Bay areas. The locations of the dune sheets are directly related to sand accumulations in marine low-stand depocenters that supplied sand to the adjacent dune fields by eolian transport across the emerged inner shelves. The San Francisco shelf depocenter is apparently localized at a midshelf bight (−50 to −100 m elevation) that extends 25 km (east–west) offshore of a paleoriver mouth of a major river system, the Sacramento–San Joaquin River. The Monterey Bay shelf depocenter is bounded alongshore by major headlands and converging paleoshorelines (−30 to −90 m elevation) that effectively trapped littoral sand from small coastal drainages, primarily the Salinas River. High vertical rates of neotectonic deformation in the San Francisco dune sheet (0.4–1.0 mm y−1) limited dune sheet longevity and deposit thickness (5–35 m). Low uplift rates (~0.1 mm y−1) in the central Monterey Bay dune sheet permitted deposit accumulations of up to 250 m thickness. The differences in dune sheet extent, thickness, and age resulted from key differences in localized shelf accommodation space and coastal neotectonic vertical movements. Title: Origins of Quaternary Coastal Dune Sheets in San Francisco and Monterey Bay, Central California Coast, U.S.A.: Reflecting Contrasts in Shelf Depocenters and Coastal Neotectonics Author: Peterson, Curt D., Stock, Errol, Meyer, Jack, Kaijankoski, Philip, Price, David M. Year: 2015 The San Francisco and Monterey Bay coastal dune sheets derive from similar origins in the central California coast but differ substantially in size (respectively, ~400 and ~900 km2) and age (respectively, 1.0 Ma). The San Francisco dune sheet is restricted to a short alongshore interval (km) within a relatively straight coastline (150 km in length) that borders a broad shelf (~40 km in width). The Monterey Bay dune sheet is restricted to the Monterey Bay embayment (41 km alongshore length). The embayment includes a very narrow shelf (3–15 km in width), which is dissected by the Monterey Submarine Canyon. Generally low onshore topographic relief (elevation) likely enhanced inland transgression of Late Pleistocene dune fields in both the San Francisco and Monterey Bay areas. The locations of the dune sheets are directly related to sand accumulations in marine low-stand depocenters that supplied sand to the adjacent dune fields by eolian transport across the emerged inner shelves. The San Francisco shelf depocenter is apparently localized at a midshelf bight (−50 to −100 m elevation) that extends 25 km (east–west) offshore of a paleoriver mouth of a major river system, the Sacramento–San Joaquin River. The Monterey Bay shelf depocenter is bounded alongshore by major headlands and converging paleoshorelines (−30 to −90 m elevation) that effectively trapped littoral sand from small coastal drainages, primarily the Salinas River. High vertical rates of neotectonic deformation in the San Francisco dune sheet (0.4–1.0 mm y−1) limited dune sheet longevity and deposit thickness (5–35 m). Low uplift rates (~0.1 mm y−1) in the central Monterey Bay dune sheet permitted deposit accumulations of up to 250 m thickness. The differences in dune sheet extent, thickness, and age resulted from key differences in localized shelf accommodation space and coastal neotectonic vertical movements. Close

• 49. [Article] The structural controls of the Vale Rhinehart Buttes complex, Vale KGRA, Malheur County, Oregon

  The Vale KGRA is characterized by high heat flow, two to five times higher than the worldwide average, and by numerous hot springs. The hot springs are aligned along faults. This phenomena is typical of ...

  Citation × Citation Citation Abstract Copy Title: The structural controls of the Vale Rhinehart Buttes complex, Vale KGRA, Malheur County, Oregon Author: Doerr, John Timothy Year: 1986 The Vale KGRA is characterized by high heat flow, two to five times higher than the worldwide average, and by numerous hot springs. The hot springs are aligned along faults. This phenomena is typical of a Basin and Range type geothermal system. The hot geothermal fluids migrate upward along the more permeable, fault planes. The rocks exposed in the Vale area are the Pliocene Chalk Butte formation and the Pleistocene beds of Captain Keeney Pass. Both units are composed of volcaniclastic siltstones, sandstones and conglomerates. The units are differentiated by color, texture and degree of lithification. About 200 meters of the Chalk Butte formation and 100 meters of the beds of Captain Keeney Pass are exposed in the area. Silicification is wide spread in the rocks of the Chalk Butte formation. Title: The structural controls of the Vale Rhinehart Buttes complex, Vale KGRA, Malheur County, Oregon Author: Doerr, John Timothy Year: 1986 The Vale KGRA is characterized by high heat flow, two to five times higher than the worldwide average, and by numerous hot springs. The hot springs are aligned along faults. This phenomena is typical of a Basin and Range type geothermal system. The hot geothermal fluids migrate upward along the more permeable, fault planes. The rocks exposed in the Vale area are the Pliocene Chalk Butte formation and the Pleistocene beds of Captain Keeney Pass. Both units are composed of volcaniclastic siltstones, sandstones and conglomerates. The units are differentiated by color, texture and degree of lithification. About 200 meters of the Chalk Butte formation and 100 meters of the beds of Captain Keeney Pass are exposed in the area. Silicification is wide spread in the rocks of the Chalk Butte formation. Close

• 50. [Article] A Tale of Three Sisters: Reconstructing the Holocene glacial history and paleoclimate record at Three Sisters Volcanoes, Oregon, United States

  At least four glacial stands occurred since 6.5 ka B.P. based on moraines located on the eastern flanks of the Three Sisters Volcanoes and the northern flanks of Broken Top Mountain in the Central Oregon ...

  Citation × Citation Citation Abstract Copy Title: A Tale of Three Sisters: Reconstructing the Holocene glacial history and paleoclimate record at Three Sisters Volcanoes, Oregon, United States Author: Marcott, Shaun Andrew Year: 2005 At least four glacial stands occurred since 6.5 ka B.P. based on moraines located on the eastern flanks of the Three Sisters Volcanoes and the northern flanks of Broken Top Mountain in the Central Oregon Cascades. The youngest of these advances was the Little Ice Age (LIA) glaciation, which reached its maximum advance 150-200 yrs. B.P. and is defined by the large sharp crested and unvegetated moraines adjacent to the modern glaciers. In isolated locations less than 100 m downslope from these moraines, a second set of sparsely vegetated lateral moraines marks the Late-Neoglacial stand of the glaciers between 2.1 ± 0.4 and 7.7 ka B.P, A third set of Early-Neoglacial end moraines is 300-700 meters downslope of the modern glacier termini, and postdates 7.7 ka B.P. From SST temperature data (Barron et al., 2003) and a speleothem record (Vacco, 2003), we infer that this advance occurred between 4.5 and 6.5 ka B.P. Finally, the Fountonnor stand is marked by moraines 500-900 meters downslope of the modern glacier termini, and we infer these are latest Pleistocene or early Holocene. Modem equilibrium line altitudes (ELAs) at the Three Sisters and Broken Top are approximately 2500 - 2600 m. During the LIA, the ELAs were 40 - 180 m lower, requiring cooler mean summer temperatures by 0.7 - 1.0°C and winter snowfall to increase by 10 - 60 cm water equivalent. The average Early Neoglacial and Fountonnor ELAs were 130 - 300 m and 290 - 320 m lower than modem glaciers, respectively, requiring air temperatures to be 0.7 - 1.6°C and 1.5 - 1.7°C cooler during the summer and winter snowfall to be 40 - 100 cm water equivalent and 90 - 100 cm water equivalent greater. Title: A Tale of Three Sisters: Reconstructing the Holocene glacial history and paleoclimate record at Three Sisters Volcanoes, Oregon, United States Author: Marcott, Shaun Andrew Year: 2005 At least four glacial stands occurred since 6.5 ka B.P. based on moraines located on the eastern flanks of the Three Sisters Volcanoes and the northern flanks of Broken Top Mountain in the Central Oregon Cascades. The youngest of these advances was the Little Ice Age (LIA) glaciation, which reached its maximum advance 150-200 yrs. B.P. and is defined by the large sharp crested and unvegetated moraines adjacent to the modern glaciers. In isolated locations less than 100 m downslope from these moraines, a second set of sparsely vegetated lateral moraines marks the Late-Neoglacial stand of the glaciers between 2.1 ± 0.4 and 7.7 ka B.P, A third set of Early-Neoglacial end moraines is 300-700 meters downslope of the modern glacier termini, and postdates 7.7 ka B.P. From SST temperature data (Barron et al., 2003) and a speleothem record (Vacco, 2003), we infer that this advance occurred between 4.5 and 6.5 ka B.P. Finally, the Fountonnor stand is marked by moraines 500-900 meters downslope of the modern glacier termini, and we infer these are latest Pleistocene or early Holocene. Modem equilibrium line altitudes (ELAs) at the Three Sisters and Broken Top are approximately 2500 - 2600 m. During the LIA, the ELAs were 40 - 180 m lower, requiring cooler mean summer temperatures by 0.7 - 1.0°C and winter snowfall to increase by 10 - 60 cm water equivalent. The average Early Neoglacial and Fountonnor ELAs were 130 - 300 m and 290 - 320 m lower than modem glaciers, respectively, requiring air temperatures to be 0.7 - 1.6°C and 1.5 - 1.7°C cooler during the summer and winter snowfall to be 40 - 100 cm water equivalent and 90 - 100 cm water equivalent greater. Close