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• 1. [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

• 2. [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

• 3. [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

• 4. [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

• 5. [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

• 6. [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

• 7. [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

• 8. [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

• 9. [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

• 10. [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