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• 381. [Article] Sequence stratigraphy and lithofacies of the middle Eocene upper McIntosh and Cowlitz Formations, geology of the Grays River Volcanics, Castle Rock - Germany Creek area, southwest Washington

  A composite 732-rn thick section in Germany Creek of middle Eocene upper McIntosh and lower Cowlitz Formations, as well as the lower Grays River Volcanics, was studied using bio-, magneto- and lithostratigraphy ...

  Citation × Citation Citation Abstract Copy Title: Sequence stratigraphy and lithofacies of the middle Eocene upper McIntosh and Cowlitz Formations, geology of the Grays River Volcanics, Castle Rock - Germany Creek area, southwest Washington Author: Kleibacker, Derik W. A composite 732-rn thick section in Germany Creek of middle Eocene upper McIntosh and lower Cowlitz Formations, as well as the lower Grays River Volcanics, was studied using bio-, magneto- and lithostratigraphy to construct a sequence stratigraphic framework and assess hydrocarbon exploration potential. The upper McIntosh Formation forms a complete 3rd order depositional cycle that includes shallow marine, tide- and wave-dominated sandstones (upper McIntosh sandstone member) and overlying bathyal to outer-shelf siltstone (upper Mcintosh siltsone member). The upper McIntosh Formation coffelates to Chrons C19r (41.5 -42.5 Ma) and lower Chron 19n (41.5-41.2 Ma). A 31 order sequence boundary straddling Chron 19n (41.2-41.5 Ma) shows truncation of the highstand upper McIntosh siltstone by prograding lowstand shoreface parasequences of the lower Cowlitz Formation. The overlying (300 m thick) shoreface transgressive (TST) and highstand system tracts (HST) of the Cowlitz Formation range in age from 41.5-41.2 Ma to 39.35 ±0.36 Ma. The Cowlitz Formation HST of the study area chronostratigraphically correlates to the reservoir Clark arid Wilson sandstone member of the Mist Gas Field Cowlitz Formation and to informal unit 1A and lower unit lB of the type-Cowlitz Formation, southwest Washington. The Grays River Volcanics of the study area are subdivided by an intraformational unconformity defining the upper (~150-m thick; 38.6-36.8 Ma) and lower (1250-m thick; 40.1-39 Ma) Grays River Volcanics subunits. Two subalkaline olivine- augite tholeiitic basalt flows of the lower Grays River Volcanics conformably overlying the Cowlitz Formation in Germany Creek were 40Ar/39Ar dated at 40.09 ±0.34 Ma and 39.35 ±0.36 Ma. The tholeiitic upper Grays River basalt unconformably overlies the lower Grays River Volcanics and the Cowlitz Formation. Numerous sub-parallel, northeast and minor northwest trending Grays River dikes (40Ar/39Ar dated at 39.98 ±0.29 and 39.56 ±0.41 Ma) attest to extension of the study area during the eruption of the Grays River Volcanics. The Oligocene Lincoln Creek Formation (~70m) consists of bioturbated tuffaceous siltstone and interbedded silty sandstone with casts and molds of articulated mollusks. Geochemistry, normal polarity, and dikytaxitic texture of the 50-60 m thick Grande Ronde basalt are indicative of the Sentinel Bluffs unit (15.6 Ma) (Columbia River Basalt Group). The Arkansas Anticline and three fault sets: (1) north-northwest- and (2) northwest-trending dextral oblique-slip faults, and (3) subordinate northeast-trending conjugate sinistral oblique-slip faults are related to two periods of deformation. They are: (1) dextral transtension resulting in horst and graben style faulting, beginning 40-39.5 Ma and terminating prior to the eruption of the upper Grays River volcanics (38.6 Ma); (2) post-middle Miocene period of dextral transpression, including dextral reactivation of normal faults and associated broad regional northwest-trending folding (e.g. Arkansas Anticline). Small normal fault block similar to the Mist Gas Field provide structural traps throughout southwest Washington. Petrography of micaceous lithic arkoses of the upper McIntosh sandstone and Cowlitz Formation indicates reservoir-quality sandstones with an estimated porosity of 16-19%. The most likely hydrocarbon exploration play involves the subtidal to shoreface upper McIntosh Formation sandstone member. Title: Sequence stratigraphy and lithofacies of the middle Eocene upper McIntosh and Cowlitz Formations, geology of the Grays River Volcanics, Castle Rock - Germany Creek area, southwest Washington Author: Kleibacker, Derik W. A composite 732-rn thick section in Germany Creek of middle Eocene upper McIntosh and lower Cowlitz Formations, as well as the lower Grays River Volcanics, was studied using bio-, magneto- and lithostratigraphy to construct a sequence stratigraphic framework and assess hydrocarbon exploration potential. The upper McIntosh Formation forms a complete 3rd order depositional cycle that includes shallow marine, tide- and wave-dominated sandstones (upper McIntosh sandstone member) and overlying bathyal to outer-shelf siltstone (upper Mcintosh siltsone member). The upper McIntosh Formation coffelates to Chrons C19r (41.5 -42.5 Ma) and lower Chron 19n (41.5-41.2 Ma). A 31 order sequence boundary straddling Chron 19n (41.2-41.5 Ma) shows truncation of the highstand upper McIntosh siltstone by prograding lowstand shoreface parasequences of the lower Cowlitz Formation. The overlying (300 m thick) shoreface transgressive (TST) and highstand system tracts (HST) of the Cowlitz Formation range in age from 41.5-41.2 Ma to 39.35 ±0.36 Ma. The Cowlitz Formation HST of the study area chronostratigraphically correlates to the reservoir Clark arid Wilson sandstone member of the Mist Gas Field Cowlitz Formation and to informal unit 1A and lower unit lB of the type-Cowlitz Formation, southwest Washington. The Grays River Volcanics of the study area are subdivided by an intraformational unconformity defining the upper (~150-m thick; 38.6-36.8 Ma) and lower (1250-m thick; 40.1-39 Ma) Grays River Volcanics subunits. Two subalkaline olivine- augite tholeiitic basalt flows of the lower Grays River Volcanics conformably overlying the Cowlitz Formation in Germany Creek were 40Ar/39Ar dated at 40.09 ±0.34 Ma and 39.35 ±0.36 Ma. The tholeiitic upper Grays River basalt unconformably overlies the lower Grays River Volcanics and the Cowlitz Formation. Numerous sub-parallel, northeast and minor northwest trending Grays River dikes (40Ar/39Ar dated at 39.98 ±0.29 and 39.56 ±0.41 Ma) attest to extension of the study area during the eruption of the Grays River Volcanics. The Oligocene Lincoln Creek Formation (~70m) consists of bioturbated tuffaceous siltstone and interbedded silty sandstone with casts and molds of articulated mollusks. Geochemistry, normal polarity, and dikytaxitic texture of the 50-60 m thick Grande Ronde basalt are indicative of the Sentinel Bluffs unit (15.6 Ma) (Columbia River Basalt Group). The Arkansas Anticline and three fault sets: (1) north-northwest- and (2) northwest-trending dextral oblique-slip faults, and (3) subordinate northeast-trending conjugate sinistral oblique-slip faults are related to two periods of deformation. They are: (1) dextral transtension resulting in horst and graben style faulting, beginning 40-39.5 Ma and terminating prior to the eruption of the upper Grays River volcanics (38.6 Ma); (2) post-middle Miocene period of dextral transpression, including dextral reactivation of normal faults and associated broad regional northwest-trending folding (e.g. Arkansas Anticline). Small normal fault block similar to the Mist Gas Field provide structural traps throughout southwest Washington. Petrography of micaceous lithic arkoses of the upper McIntosh sandstone and Cowlitz Formation indicates reservoir-quality sandstones with an estimated porosity of 16-19%. The most likely hydrocarbon exploration play involves the subtidal to shoreface upper McIntosh Formation sandstone member. Close

• 382. [Article] Susceptibility of select salmonids to Myxobolus cerebralis and effects of exposure on anadromous salmonids in Oregon

  Myxobolus cerebralis, a myxozoan parasite of salmonids, is the causative agent of whirling disease. The parasite is considered widespread throughout northeastern Oregon in the Grande Ronde and Imnaha River ...

  Citation × Citation Citation Abstract Copy Title: Susceptibility of select salmonids to Myxobolus cerebralis and effects of exposure on anadromous salmonids in Oregon Author: Sollid, Sarah A. Myxobolus cerebralis, a myxozoan parasite of salmonids, is the causative agent of whirling disease. The parasite is considered widespread throughout northeastern Oregon in the Grande Ronde and Imnaha River basins where threatened and endangered salmonid populations exist. The work presented in this thesis comprises several studies that assess the effects of M. cerebralis on resident and anadromous salmonids in Oregon. Laboratory challenges to determine the susceptibility of indigenous Deschutes River, Oregon, salmonids to M. cerebralis were conducted as part of a study to assess the risk of reintroducing anadromous salmon above a migration barrier on that river. This study was the first to assess the susceptibility of kokanee salmon Oncorhynchus nerka to M. cerebralis, and results contribute to the understanding of salmonid susceptibility as it relates to species and age. Further, this study demonstrates that the indigenous salmonids present in the river are susceptible to infection, but resident rainbow trout Oncorhynchus mykiss would be most at risk should introduction of M. cerebralis occur in this system. The susceptibility of chinook salmon Oncorhynchus tshawytscha to M. cerebralis was assessed following laboratory challenges at different ages to different parasite levels. Results from this study indicate that chinook salmon are more resistant to M. cerebralis infection than susceptible rainbow trout; resistance to disease developed in chinook salmon exposed after 3 weeks of age. Sustained exposures to a low parasite dose were performed to model the conditions chinook salmon would encounter in a natural exposure. Following continuous exposure to low parasite densities, chinook salmon were very resistant to infection and disease. Managed populations of chinook salmon and steelhead Oncorhynchus mykiss juveniles are held in acclimation facilities on their natal streams before release to commence their seaward migration. Rainbow trout fry were held at each of the acclimation facilities to detect the presence of M. cerebralis and to assess the prevalence of exposure during the acclimation period. Results from these exposures indicate that the Wallowa acclimation facility is a high-risk site for parasite exposure of steelhead juveniles. Further, detection was confirmed in several rivers and streams where the presence of M. cerebralis has been suggested. Finally, a preliminary study on the effect of M. cerebralis on survival of steelhead juveniles upon transfer to saltwater was conducted. Results from this study indicate that M. cerebralis exposure and infection may increase mortality among juvenile steelhead during saltwater adaptation. Title: Susceptibility of select salmonids to Myxobolus cerebralis and effects of exposure on anadromous salmonids in Oregon Author: Sollid, Sarah A. Myxobolus cerebralis, a myxozoan parasite of salmonids, is the causative agent of whirling disease. The parasite is considered widespread throughout northeastern Oregon in the Grande Ronde and Imnaha River basins where threatened and endangered salmonid populations exist. The work presented in this thesis comprises several studies that assess the effects of M. cerebralis on resident and anadromous salmonids in Oregon. Laboratory challenges to determine the susceptibility of indigenous Deschutes River, Oregon, salmonids to M. cerebralis were conducted as part of a study to assess the risk of reintroducing anadromous salmon above a migration barrier on that river. This study was the first to assess the susceptibility of kokanee salmon Oncorhynchus nerka to M. cerebralis, and results contribute to the understanding of salmonid susceptibility as it relates to species and age. Further, this study demonstrates that the indigenous salmonids present in the river are susceptible to infection, but resident rainbow trout Oncorhynchus mykiss would be most at risk should introduction of M. cerebralis occur in this system. The susceptibility of chinook salmon Oncorhynchus tshawytscha to M. cerebralis was assessed following laboratory challenges at different ages to different parasite levels. Results from this study indicate that chinook salmon are more resistant to M. cerebralis infection than susceptible rainbow trout; resistance to disease developed in chinook salmon exposed after 3 weeks of age. Sustained exposures to a low parasite dose were performed to model the conditions chinook salmon would encounter in a natural exposure. Following continuous exposure to low parasite densities, chinook salmon were very resistant to infection and disease. Managed populations of chinook salmon and steelhead Oncorhynchus mykiss juveniles are held in acclimation facilities on their natal streams before release to commence their seaward migration. Rainbow trout fry were held at each of the acclimation facilities to detect the presence of M. cerebralis and to assess the prevalence of exposure during the acclimation period. Results from these exposures indicate that the Wallowa acclimation facility is a high-risk site for parasite exposure of steelhead juveniles. Further, detection was confirmed in several rivers and streams where the presence of M. cerebralis has been suggested. Finally, a preliminary study on the effect of M. cerebralis on survival of steelhead juveniles upon transfer to saltwater was conducted. Results from this study indicate that M. cerebralis exposure and infection may increase mortality among juvenile steelhead during saltwater adaptation. Close

• 383. [Article] Spatial patterns of fuel management activities and their effects on wildfire behavior

  Fuel management has been used as an effective local strategy to reduce the undesirable consequences of wildfires. Many efforts toward scheduling of fuel management activities across a broader landscape ...

  Citation × Citation Citation Abstract Copy Title: Spatial patterns of fuel management activities and their effects on wildfire behavior Author: Kim, Young-Hwan Fuel management has been used as an effective local strategy to reduce the undesirable consequences of wildfires. Many efforts toward scheduling of fuel management activities across a broader landscape have been proposed, with the hope of achieving larger landscape-scale management effects. However, scheduling of fuel management treatments across the broader landscape is limited by understandings of how individual management activities aggregate to larger scales and how they affect the behavior of wildfires. Since full coverage of a landscape with fuels management treatments is unlikely, it is necessary to examine the effects of a spatial pattern of individual management activities at the landscape scale. In this research, four spatial patterns of fuel management activities – dispersed, clumped, random, and regular – were tested to investigate their potential for reducing the risk of severe wildfire. A new methodology was developed for optimizing fuel management patterns across a landscape based on a heuristic technique and GIS databases. To quantify the cumulative effects of fuel management patterns for disrupting the progress of wildfires, overall flame length, fireline intensity, and fire size were measured for simulated fires, using a fire growth simulation model, FARSITE. The management scenarios generated from the scheduling model presented a variety of dispersion and treatment sizes, but also evenly distributed the harvest volume through the multi-decade time horizon. The optimized spatial patterns were qualified through visual examination as well as a statistical assessment. Through this research, I have learned that the efficiency of fuels management activities for reducing severity of wildfire is primarily influenced by treatment size, type, and intensity. Most importantly, treatment types and intensity are the critical factor to disrupt human-caused wildfires. The regular pattern seemed to be the most acceptable for either random ignitions or hypothetical human-caused ignitions. It provided the highest frequency in which simulated fires could contact the treated units, and higher treatment intensity measured by amount of harvested volume from a unit area. To enhance the results of this research, we suggest that one should utilize more feasible management prescriptions for post-fire fuel conditions, and expand ignition sources to other type of human-caused ignitions or natural-caused ignitions. Title: Spatial patterns of fuel management activities and their effects on wildfire behavior Author: Kim, Young-Hwan Fuel management has been used as an effective local strategy to reduce the undesirable consequences of wildfires. Many efforts toward scheduling of fuel management activities across a broader landscape have been proposed, with the hope of achieving larger landscape-scale management effects. However, scheduling of fuel management treatments across the broader landscape is limited by understandings of how individual management activities aggregate to larger scales and how they affect the behavior of wildfires. Since full coverage of a landscape with fuels management treatments is unlikely, it is necessary to examine the effects of a spatial pattern of individual management activities at the landscape scale. In this research, four spatial patterns of fuel management activities – dispersed, clumped, random, and regular – were tested to investigate their potential for reducing the risk of severe wildfire. A new methodology was developed for optimizing fuel management patterns across a landscape based on a heuristic technique and GIS databases. To quantify the cumulative effects of fuel management patterns for disrupting the progress of wildfires, overall flame length, fireline intensity, and fire size were measured for simulated fires, using a fire growth simulation model, FARSITE. The management scenarios generated from the scheduling model presented a variety of dispersion and treatment sizes, but also evenly distributed the harvest volume through the multi-decade time horizon. The optimized spatial patterns were qualified through visual examination as well as a statistical assessment. Through this research, I have learned that the efficiency of fuels management activities for reducing severity of wildfire is primarily influenced by treatment size, type, and intensity. Most importantly, treatment types and intensity are the critical factor to disrupt human-caused wildfires. The regular pattern seemed to be the most acceptable for either random ignitions or hypothetical human-caused ignitions. It provided the highest frequency in which simulated fires could contact the treated units, and higher treatment intensity measured by amount of harvested volume from a unit area. To enhance the results of this research, we suggest that one should utilize more feasible management prescriptions for post-fire fuel conditions, and expand ignition sources to other type of human-caused ignitions or natural-caused ignitions. Close

• 384. [Article] Fish movement and assemblage dynamics in a Pacific Northwest riverscape

  This study examined fish movements and assemblage dynamics in the Wenaha, Grande Ronde, Snake river system of northeast Oregon and southeast Washington. I investigated the role of fish movement in the ...

  Citation × Citation Citation Abstract Copy Title: Fish movement and assemblage dynamics in a Pacific Northwest riverscape Author: Baxter, Colden V. This study examined fish movements and assemblage dynamics in the Wenaha, Grande Ronde, Snake river system of northeast Oregon and southeast Washington. I investigated the role of fish movement in the dynamics of stream fish assemblages and evaluated relationships between species movement, assemblage structure, and the heterogeneity of habitat at multiple scales within the river network. In doing so, I employed a landscape approach, visualizing the heterogeneity and dynamics of the system as a "riverscape" that sets the stage for the ecology of stream fishes. I quantified fish assemblage dynamics, characterized the nature and extent of movement by representative fish species, and assessed spatial and temporal heterogeneity of stream habitat within the river network. I applied multiple methods, including underwater fish surveys and radio telemetry, and used multiple sampling approaches that allowed me to detect patterns at nested spatial and temporal scales. I found that spatial patterns in fish assemblage structure were highly dynamic over seasonal to diel temporal scales. Seasonal changes in fish assemblage patterns along the length of the river system were primarily driven by the migration of native fishes such as mountain whitefish, bull trout, and largescale suckers. These highly migratory species exhibited a diverse array of movement strategies and often had annual ranges of hundreds of kilometers. The movement of fishes at smaller spatial scales influenced diel dynamics of fish assemblage patterns. Important habitat features at stream, valley segment and channel unit scales were separated spatially, and fish species exhibited a variety of migratory strategies that reflected the complementary use of habitats distributed throughout the riverscape. The importance of fish migration and the dynamic nature of stream fish assemblages and fish habitat relationships should be taken into account in research and conservation of stream fishes. Current conceptual frameworks for stream fish assemblages do not fully reflect the temporal complexity of stream fish life histories or the spatial heterogeneity of stream habitat. I introduce an alternative framework by integrating fish movement into a dynamic perspective of assemblages set within the context of the riverscape, and raise questions regarding the nature of ecological communities. Title: Fish movement and assemblage dynamics in a Pacific Northwest riverscape Author: Baxter, Colden V. This study examined fish movements and assemblage dynamics in the Wenaha, Grande Ronde, Snake river system of northeast Oregon and southeast Washington. I investigated the role of fish movement in the dynamics of stream fish assemblages and evaluated relationships between species movement, assemblage structure, and the heterogeneity of habitat at multiple scales within the river network. In doing so, I employed a landscape approach, visualizing the heterogeneity and dynamics of the system as a "riverscape" that sets the stage for the ecology of stream fishes. I quantified fish assemblage dynamics, characterized the nature and extent of movement by representative fish species, and assessed spatial and temporal heterogeneity of stream habitat within the river network. I applied multiple methods, including underwater fish surveys and radio telemetry, and used multiple sampling approaches that allowed me to detect patterns at nested spatial and temporal scales. I found that spatial patterns in fish assemblage structure were highly dynamic over seasonal to diel temporal scales. Seasonal changes in fish assemblage patterns along the length of the river system were primarily driven by the migration of native fishes such as mountain whitefish, bull trout, and largescale suckers. These highly migratory species exhibited a diverse array of movement strategies and often had annual ranges of hundreds of kilometers. The movement of fishes at smaller spatial scales influenced diel dynamics of fish assemblage patterns. Important habitat features at stream, valley segment and channel unit scales were separated spatially, and fish species exhibited a variety of migratory strategies that reflected the complementary use of habitats distributed throughout the riverscape. The importance of fish migration and the dynamic nature of stream fish assemblages and fish habitat relationships should be taken into account in research and conservation of stream fishes. Current conceptual frameworks for stream fish assemblages do not fully reflect the temporal complexity of stream fish life histories or the spatial heterogeneity of stream habitat. I introduce an alternative framework by integrating fish movement into a dynamic perspective of assemblages set within the context of the riverscape, and raise questions regarding the nature of ecological communities. Close

• 385. [Article] Potential Impacts of Formation Waters on the Integrity of Class H Cement and Reservoir Rock in Carbon (Co-)Sequestration Settings

  The focus of this research is to characterize the risk of carbon sequestration under downhole conditions with regards to wellbore cement integrity. The primary research objective was to understand the ...

  Citation × Citation Citation Abstract Copy Title: Potential Impacts of Formation Waters on the Integrity of Class H Cement and Reservoir Rock in Carbon (Co-)Sequestration Settings Author: Verba, Circe Year: 2013 The focus of this research is to characterize the risk of carbon sequestration under downhole conditions with regards to wellbore cement integrity. The primary research objective was to understand the geochemical interactions of simulated sequestration brines and wellbore cement. There are four key focuses of this study with regards to cement interaction: 1) Simulated brines saturated with Supercritical CO2 and CO2-O2; 2) Adjacent formation host rock under sequestration conditions; 3) Geochemical modeling using CHIM-XPT based on the experimental studies of points 1) and 2) above; 4) Geomechanical strength tests of CO2 exposed cements. First, the interaction of cement with supercritical CO2, CO2-saturated brines, and CO2-O2 mixtures at 50 °C, 85 °C, and 28.9 MPa was evaluated. Cement exposed to a lower salinity brine (1 M) had a larger alteration depth (1.25 mm) compared to cement exposed to a higher salinity brine (2.2 M) (0.836 mm). CO2-O2 exposed cements displayed alteration depths of 1.6 mm at 85 °C and 0.7 mm at 50 °C for 1 M. The cement exposed to the 2.17 M solution had an alteration extending 1.685 mm. The second focus studied the influence of adjacent formations and observed mineral trapping in the Grande Ronde Basalt-cement. Studies of Mt. Simon Sandstone-cement interaction provided evidence for high CO2 storage capacity. The third focus is geochemical modeling using CHIM-XPT. Pure CO2 saturated brines yielded a pH of 3.0 at 1 M and 3.85 at 2.17 M. The CO2-O2 gas run calculated a pH of 3.96 at 1 M and 3.85 at 2.17 M. The Pasco solution after exposure had a pH of 6.97 and an estimated dissolved 161 g of CO2 (g). The pH of the Illinois Basin brine and Mt. Simon sandstone [and cement paste] was 5.8 with an estimated 139 g of CO2 consumed. Lastly, geomechanical tests on CO2 exposed cements indicated that addition of oxygen or changes in temperature play a key role in compressive and tensile strength, decreasing strength by 20-35%. This research highlighted the importance of representing the in-situ wellbore environment when conducting laboratory experiments. This dissertation includes previously published and unpublished co-authored material. Title: Potential Impacts of Formation Waters on the Integrity of Class H Cement and Reservoir Rock in Carbon (Co-)Sequestration Settings Author: Verba, Circe Year: 2013 The focus of this research is to characterize the risk of carbon sequestration under downhole conditions with regards to wellbore cement integrity. The primary research objective was to understand the geochemical interactions of simulated sequestration brines and wellbore cement. There are four key focuses of this study with regards to cement interaction: 1) Simulated brines saturated with Supercritical CO2 and CO2-O2; 2) Adjacent formation host rock under sequestration conditions; 3) Geochemical modeling using CHIM-XPT based on the experimental studies of points 1) and 2) above; 4) Geomechanical strength tests of CO2 exposed cements. First, the interaction of cement with supercritical CO2, CO2-saturated brines, and CO2-O2 mixtures at 50 °C, 85 °C, and 28.9 MPa was evaluated. Cement exposed to a lower salinity brine (1 M) had a larger alteration depth (1.25 mm) compared to cement exposed to a higher salinity brine (2.2 M) (0.836 mm). CO2-O2 exposed cements displayed alteration depths of 1.6 mm at 85 °C and 0.7 mm at 50 °C for 1 M. The cement exposed to the 2.17 M solution had an alteration extending 1.685 mm. The second focus studied the influence of adjacent formations and observed mineral trapping in the Grande Ronde Basalt-cement. Studies of Mt. Simon Sandstone-cement interaction provided evidence for high CO2 storage capacity. The third focus is geochemical modeling using CHIM-XPT. Pure CO2 saturated brines yielded a pH of 3.0 at 1 M and 3.85 at 2.17 M. The CO2-O2 gas run calculated a pH of 3.96 at 1 M and 3.85 at 2.17 M. The Pasco solution after exposure had a pH of 6.97 and an estimated dissolved 161 g of CO2 (g). The pH of the Illinois Basin brine and Mt. Simon sandstone [and cement paste] was 5.8 with an estimated 139 g of CO2 consumed. Lastly, geomechanical tests on CO2 exposed cements indicated that addition of oxygen or changes in temperature play a key role in compressive and tensile strength, decreasing strength by 20-35%. This research highlighted the importance of representing the in-situ wellbore environment when conducting laboratory experiments. This dissertation includes previously published and unpublished co-authored material. Close

• 386. [Article] Lower Snake River Compensation Plan: Oregon Summer Steelhead Evaluation Studies 1999 and 2000 Bi-Annual Progress Report; January 1, 1999 through December 31, 2000

  Abstract -- The purpose of this progress report is to provide summary information for Lower Snake River Compensation Plan (LSRCP) summer steelhead programs operated by ODFW in the Grande Ronde and lmnaha ...

  Citation × Citation Citation Abstract Copy Title: Lower Snake River Compensation Plan: Oregon Summer Steelhead Evaluation Studies 1999 and 2000 Bi-Annual Progress Report; January 1, 1999 through December 31, 2000 Abstract -- The purpose of this progress report is to provide summary information for Lower Snake River Compensation Plan (LSRCP) summer steelhead programs operated by ODFW in the Grande Ronde and lmnaha river basins during 1999 and 2000. These ongoing monitoring programs provide technical, logistical, and biological information to managers charged with maintaining viable salmon and steelhead populations and associated fisheries in Northeast Oregon. This report summarizes fish culture monitoring data for LSRCP facilities for summer steelhead. These data serve as the basis for the analysis of trends in culture performance. Generally speaking, the data in this report were derived from hatchery inventories and standard databases (i.e., PSMFC, Coded-wire tag) or through standard measuring techniques. As such, specific protocols are usually not described. In cases where expansions of data or unique methodologies were used, protocols are described in more detail. Additional descriptions of protocols can be found in the 1999 and 2000 work statements (Carmichael et al. 1999a, Carmichael and Ruzycki 2000). Coded-wire tag (CWT) data that were collected from 1999-2000 adult returns were used to evaluate smolt-to-adult survival rates in experimental rearing and release groups. In 1999-2000, experimental treatments from which fish returned included acclimated vs. direct stream release, forced vs. volitional release, rearing site, growth, and density treatments. In 1999-2000, experimental treatments for which fish were released included forced vs. volitional, and pre-smolt release strategies. Analysis of specific survival studies will be completed once all brood years have returned and CWT data are complete for a given experiment. In addition, much of the data that we discuss in this report will be used in separate and specific evaluations of ongoing supplementation programs for steelhead in the Imnaha River basin. We began culture evaluations in 1983 and have dramatically improved many practices. Progress for work completed in previous years is presented in annual progress reports (Carmichael and Wagner, 1983; Carmichael and Messmer, 1985; Carmichael et al., 1986a, 1987, 1988a, 1988b, 1989, 1990, 1999b, 2004, 2005; Messmer et al., 1989, 1990, 1991, 1992, 1993; Flesher et al., 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1999; Whitesel et al., 1993; and Jonasson et al., 1994, 1995, 1996), United States v. Oregon production report (Carmichael et al., 1986b), and a five-year study plan (Carmichael 1989). Progress of related work completed in 1999 and 2000 is presented in summer steelhead creel annual progress reports (Flesher et al., 2000, and 2001), and in the steelhead life history, genetics, and kelt reconditioning 1997-2001 progress report (Ruzycki et al., 2003). This report is organized into fish culture monitoring for juveniles, adults, CWT recoveries, and estimates for total escapement. During the period covered in this report, steelhead from the 1994-1997 broods returned to spawn, steelhead from the 1998 and 1999 broods were released as smolts, and adult steelhead that returned to spawn were used to create the 1999 and 2000 broods. Title: Lower Snake River Compensation Plan: Oregon Summer Steelhead Evaluation Studies 1999 and 2000 Bi-Annual Progress Report; January 1, 1999 through December 31, 2000 Abstract -- The purpose of this progress report is to provide summary information for Lower Snake River Compensation Plan (LSRCP) summer steelhead programs operated by ODFW in the Grande Ronde and lmnaha river basins during 1999 and 2000. These ongoing monitoring programs provide technical, logistical, and biological information to managers charged with maintaining viable salmon and steelhead populations and associated fisheries in Northeast Oregon. This report summarizes fish culture monitoring data for LSRCP facilities for summer steelhead. These data serve as the basis for the analysis of trends in culture performance. Generally speaking, the data in this report were derived from hatchery inventories and standard databases (i.e., PSMFC, Coded-wire tag) or through standard measuring techniques. As such, specific protocols are usually not described. In cases where expansions of data or unique methodologies were used, protocols are described in more detail. Additional descriptions of protocols can be found in the 1999 and 2000 work statements (Carmichael et al. 1999a, Carmichael and Ruzycki 2000). Coded-wire tag (CWT) data that were collected from 1999-2000 adult returns were used to evaluate smolt-to-adult survival rates in experimental rearing and release groups. In 1999-2000, experimental treatments from which fish returned included acclimated vs. direct stream release, forced vs. volitional release, rearing site, growth, and density treatments. In 1999-2000, experimental treatments for which fish were released included forced vs. volitional, and pre-smolt release strategies. Analysis of specific survival studies will be completed once all brood years have returned and CWT data are complete for a given experiment. In addition, much of the data that we discuss in this report will be used in separate and specific evaluations of ongoing supplementation programs for steelhead in the Imnaha River basin. We began culture evaluations in 1983 and have dramatically improved many practices. Progress for work completed in previous years is presented in annual progress reports (Carmichael and Wagner, 1983; Carmichael and Messmer, 1985; Carmichael et al., 1986a, 1987, 1988a, 1988b, 1989, 1990, 1999b, 2004, 2005; Messmer et al., 1989, 1990, 1991, 1992, 1993; Flesher et al., 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1999; Whitesel et al., 1993; and Jonasson et al., 1994, 1995, 1996), United States v. Oregon production report (Carmichael et al., 1986b), and a five-year study plan (Carmichael 1989). Progress of related work completed in 1999 and 2000 is presented in summer steelhead creel annual progress reports (Flesher et al., 2000, and 2001), and in the steelhead life history, genetics, and kelt reconditioning 1997-2001 progress report (Ruzycki et al., 2003). This report is organized into fish culture monitoring for juveniles, adults, CWT recoveries, and estimates for total escapement. During the period covered in this report, steelhead from the 1994-1997 broods returned to spawn, steelhead from the 1998 and 1999 broods were released as smolts, and adult steelhead that returned to spawn were used to create the 1999 and 2000 broods. Close

• 387. [Article] Lower Snake River Compensation Plan Oregon Evaluation Studies 1997 and 1998 Bi-Annual Progress Report, January 1, 1997 through December 31, 1998

  Abstract -- The purpose of this progress report is to provide summary information for spring Chinook salmon Lower Snake River Compensation Plan (LSRCP) programs operated by ODFW in the Grande Ronde and ...

  Citation × Citation Citation Abstract Copy Title: Lower Snake River Compensation Plan Oregon Evaluation Studies 1997 and 1998 Bi-Annual Progress Report, January 1, 1997 through December 31, 1998 Abstract -- The purpose of this progress report is to provide summary information for spring Chinook salmon Lower Snake River Compensation Plan (LSRCP) programs operated by ODFW in the Grande Ronde and Imnaha river basins during 1997 and 1998. These ongoing monitoring programs provide technical, logistical and biological information to managers charged with maintaining viable salmon populations and associated fisheries in northeast Oregon. The data in this report serve as the basis for the analysis of trends in culture performance and were derived from hatchery inventories and standard databases (i.e., PSMFC, coded-wire tag) or through standard measuring techniques. As such, specific protocols are usually not described. In cases where expansions of data or unique methodologies were used, protocols are described in more detail. Additional descriptions of protocols can be found in the 1997 and 1998 work statements (Carmichael 1989; Carmichael et al 1997; 1998). Coded-wire tag (CWT) data collected from 1997-1998 adult returns are used to evaluate smolt-to-adult survival rates in experimental rearing and release groups. In 1997-1998, experimental treatments from which salmon returned included acclimated vs. direct stream release, size at release and rearing density. In 1997-1998, experimental treatments for which salmon were released included size at release, presmolt exercise and rearing density treatments. Analysis of specific survival studies will be completed once all brood years have returned and CWT data are complete for a given experiment. In addition, much of the data that we discuss in this report will be used in separate and specific evaluations of ongoing supplementation programs for Chinook salmon in the Imnaha River Basin. We began culture evaluations in 1983 and have dramatically improved many practices. Progress for work completed in previous years is presented in annual progress reports (Carmichael and Wagner 1983; Carmichael and Messmer 1985; Carmichael et al 1986a 1987, 1988a, 1988b, 1989, 1990, 1999 and 2004; Messmer et al 1989, 1990, 1991, 1992 and 1993; Jonasson et al 1994, 1995 and 1996) and United States v. Oregon production report (Carmichael et al 1986b ). Within each section of this report, data are organized into salmon culture monitoring for juveniles, adults, CWT recoveries, compensation goals and estimates for total escapement. During the period covered in this report, Chinook salmon from the 1991-1995 brood years returned to spawn, Chinook salmon from the 1995-1996 brood year were released as smolts and adult Chinook salmon that returned to spawn were used to create the 1997 and 1998 cohorts. Title: Lower Snake River Compensation Plan Oregon Evaluation Studies 1997 and 1998 Bi-Annual Progress Report, January 1, 1997 through December 31, 1998 Abstract -- The purpose of this progress report is to provide summary information for spring Chinook salmon Lower Snake River Compensation Plan (LSRCP) programs operated by ODFW in the Grande Ronde and Imnaha river basins during 1997 and 1998. These ongoing monitoring programs provide technical, logistical and biological information to managers charged with maintaining viable salmon populations and associated fisheries in northeast Oregon. The data in this report serve as the basis for the analysis of trends in culture performance and were derived from hatchery inventories and standard databases (i.e., PSMFC, coded-wire tag) or through standard measuring techniques. As such, specific protocols are usually not described. In cases where expansions of data or unique methodologies were used, protocols are described in more detail. Additional descriptions of protocols can be found in the 1997 and 1998 work statements (Carmichael 1989; Carmichael et al 1997; 1998). Coded-wire tag (CWT) data collected from 1997-1998 adult returns are used to evaluate smolt-to-adult survival rates in experimental rearing and release groups. In 1997-1998, experimental treatments from which salmon returned included acclimated vs. direct stream release, size at release and rearing density. In 1997-1998, experimental treatments for which salmon were released included size at release, presmolt exercise and rearing density treatments. Analysis of specific survival studies will be completed once all brood years have returned and CWT data are complete for a given experiment. In addition, much of the data that we discuss in this report will be used in separate and specific evaluations of ongoing supplementation programs for Chinook salmon in the Imnaha River Basin. We began culture evaluations in 1983 and have dramatically improved many practices. Progress for work completed in previous years is presented in annual progress reports (Carmichael and Wagner 1983; Carmichael and Messmer 1985; Carmichael et al 1986a 1987, 1988a, 1988b, 1989, 1990, 1999 and 2004; Messmer et al 1989, 1990, 1991, 1992 and 1993; Jonasson et al 1994, 1995 and 1996) and United States v. Oregon production report (Carmichael et al 1986b ). Within each section of this report, data are organized into salmon culture monitoring for juveniles, adults, CWT recoveries, compensation goals and estimates for total escapement. During the period covered in this report, Chinook salmon from the 1991-1995 brood years returned to spawn, Chinook salmon from the 1995-1996 brood year were released as smolts and adult Chinook salmon that returned to spawn were used to create the 1997 and 1998 cohorts. Close

• 388. [Article] Performance of Progeny From Steelhead and Rainbow Trout Crosses - Final Report 2009

  Abstract -- Many salmonids exhibit partial migration: the phenomenon of populations partitioned into migratory and non-migratory individuals (Jonsson and Jonsson 1993). Oncorhynchus mykiss exhibit a complex ...

  Citation × Citation Citation Abstract Copy Title: Performance of Progeny From Steelhead and Rainbow Trout Crosses - Final Report 2009 Abstract -- Many salmonids exhibit partial migration: the phenomenon of populations partitioned into migratory and non-migratory individuals (Jonsson and Jonsson 1993). Oncorhynchus mykiss exhibit a complex of life-history strategies ranging from residency in small headwater streams to anadromy involving migrations of hundreds of kilometers. In the Grande Ronde River basin of northeast Oregon, both resident and anadromous life-history forms coexist, and thus populations found there likely exhibit partial migration. Partial migration may have important consequences for anadromous species listed under the Endangered Species Act (ESA). The recent decline of summer steelhead (Oncorhynchus mykiss) populations in the lower Snake River has prompted their listing under the ESA. Declines in steelhead are potentially due to elevated mortality rates associated with anadromous migrations. If resident and anadromous life-history characteristics result from a phenotypically plastic trait (i.e. a genetic trait that is highly variable due to influences from environmental factors), then elevated mortality associated with the anadromous type may be shifting the populations towards residency. Further, although the anadromous expression of the trait may be declining, the trait would not necessarily be lost. Identification of the plasticity of these traits would then be important for the management of these populations. We investigated life history traits of O. mykiss with studies in both the hatchery and natural environment. We anticipated that these complimentary approaches would allow us to evaluate the relationship between the two life-history forms. They should further allow us to explore the feasibility of using hatcheries to produce anadromous progeny from resident parents if the number of anadromous life-history forms becomes severely depressed. The overall goal of this study was to determine the plasticity of life history forms, specifically the ability of resident adults to produce anadromous progeny. Lower Snake River Compensation Plan (LSRCP) ODFW- Eastern Oregon Fish Research (EOFR) Title: Performance of Progeny From Steelhead and Rainbow Trout Crosses - Final Report 2009 Abstract -- Many salmonids exhibit partial migration: the phenomenon of populations partitioned into migratory and non-migratory individuals (Jonsson and Jonsson 1993). Oncorhynchus mykiss exhibit a complex of life-history strategies ranging from residency in small headwater streams to anadromy involving migrations of hundreds of kilometers. In the Grande Ronde River basin of northeast Oregon, both resident and anadromous life-history forms coexist, and thus populations found there likely exhibit partial migration. Partial migration may have important consequences for anadromous species listed under the Endangered Species Act (ESA). The recent decline of summer steelhead (Oncorhynchus mykiss) populations in the lower Snake River has prompted their listing under the ESA. Declines in steelhead are potentially due to elevated mortality rates associated with anadromous migrations. If resident and anadromous life-history characteristics result from a phenotypically plastic trait (i.e. a genetic trait that is highly variable due to influences from environmental factors), then elevated mortality associated with the anadromous type may be shifting the populations towards residency. Further, although the anadromous expression of the trait may be declining, the trait would not necessarily be lost. Identification of the plasticity of these traits would then be important for the management of these populations. We investigated life history traits of O. mykiss with studies in both the hatchery and natural environment. We anticipated that these complimentary approaches would allow us to evaluate the relationship between the two life-history forms. They should further allow us to explore the feasibility of using hatcheries to produce anadromous progeny from resident parents if the number of anadromous life-history forms becomes severely depressed. The overall goal of this study was to determine the plasticity of life history forms, specifically the ability of resident adults to produce anadromous progeny. Lower Snake River Compensation Plan (LSRCP) ODFW- Eastern Oregon Fish Research (EOFR) Close

• 389. [Article] Prevalence of Bacterial Kidney Disease in Natural vs. Hatchery-Reared Adult Chinook Salmon Spawned in a Hatchery and in Nature Information Reports number 2009-06

  Abstract -- Bacterial kidney disease (BKD) is a major health problem of cultured Pacific salmon, Oncorhynchus sp. It has been particularly problematic in captive broodstock programs, where the interests ...

  Citation × Citation Citation Abstract Copy Title: Prevalence of Bacterial Kidney Disease in Natural vs. Hatchery-Reared Adult Chinook Salmon Spawned in a Hatchery and in Nature Information Reports number 2009-06 Abstract -- Bacterial kidney disease (BKD) is a major health problem of cultured Pacific salmon, Oncorhynchus sp. It has been particularly problematic in captive broodstock programs, where the interests of gene conservation and fish health can conflict when spawning females with signs of BKD. Not rearing those fish reduces the genetic diversity of an already depleted population, while rearing those fish may increase the prevalence of BKD in the natural population. We used data collected during spawning at Lookingglass Fish hatchery and on spawning ground surveys to examine the prevalence of BKD, based on enzyme-linked immunosorbent assay optical density (ELISA OD) values, to monitor the prevalence of BKD in natural and hatchery-reared Chinook salmon O. tshawytscha from Grande Ronde and Imnaha basin streams in northeast Oregon. Mean ELISA OD levels differed among all sampled streams from 2004-2008 and was lowest in the Imnaha River salmon (0.0839) and highest in the Minam River (0.1750). Salmon spawned at LFH had a lower mean ELISA OD level (0.086) than those collected from carcasses on spawning ground surveys (0.118). Natural salmon mean ELISA OD level was 0.1058 and 97% were from salmon with ELISA OD level <0.2 and in hatchery salmon, 96% had an ELISA OD level <0.2 and mean ELISA OD level was 0.1138, with no difference between the groups. Over 17 years in the Imnaha River we see no difference in mean ELISA OD levels between natural and hatchery Chinook salmon. There was no difference in mean ELISA OD levels between adult Chinook salmon from wilderness (0.1663) vs. supplemented (0.1184) streams. However, when comparing mean ELISA OD for only natural Chinook salmon carcasses recovered in these streams, we found that mean ELISA OD level was higher in the wilderness streams (0.1676) than in the supplemented streams. Returning adults from the Captive Broodstock F1 generation had a higher mean ELISA OD level (0.1349) than those of Conventional Hatchery Program offspring (0.0957). Annual mean ELISA OD level decreased over time in the Lostine River stock but did not change for any of the other stocks. The data for BKD in Chinook salmon from northeast Oregon streams and hatcheries show that this disease is not prevalent and we found no evidence that the release of hatchery salmon is causing an increase in BKD prevalence in the monitored streams. However, we will continue to monitor this disease. Title: Prevalence of Bacterial Kidney Disease in Natural vs. Hatchery-Reared Adult Chinook Salmon Spawned in a Hatchery and in Nature Information Reports number 2009-06 Abstract -- Bacterial kidney disease (BKD) is a major health problem of cultured Pacific salmon, Oncorhynchus sp. It has been particularly problematic in captive broodstock programs, where the interests of gene conservation and fish health can conflict when spawning females with signs of BKD. Not rearing those fish reduces the genetic diversity of an already depleted population, while rearing those fish may increase the prevalence of BKD in the natural population. We used data collected during spawning at Lookingglass Fish hatchery and on spawning ground surveys to examine the prevalence of BKD, based on enzyme-linked immunosorbent assay optical density (ELISA OD) values, to monitor the prevalence of BKD in natural and hatchery-reared Chinook salmon O. tshawytscha from Grande Ronde and Imnaha basin streams in northeast Oregon. Mean ELISA OD levels differed among all sampled streams from 2004-2008 and was lowest in the Imnaha River salmon (0.0839) and highest in the Minam River (0.1750). Salmon spawned at LFH had a lower mean ELISA OD level (0.086) than those collected from carcasses on spawning ground surveys (0.118). Natural salmon mean ELISA OD level was 0.1058 and 97% were from salmon with ELISA OD level <0.2 and in hatchery salmon, 96% had an ELISA OD level <0.2 and mean ELISA OD level was 0.1138, with no difference between the groups. Over 17 years in the Imnaha River we see no difference in mean ELISA OD levels between natural and hatchery Chinook salmon. There was no difference in mean ELISA OD levels between adult Chinook salmon from wilderness (0.1663) vs. supplemented (0.1184) streams. However, when comparing mean ELISA OD for only natural Chinook salmon carcasses recovered in these streams, we found that mean ELISA OD level was higher in the wilderness streams (0.1676) than in the supplemented streams. Returning adults from the Captive Broodstock F1 generation had a higher mean ELISA OD level (0.1349) than those of Conventional Hatchery Program offspring (0.0957). Annual mean ELISA OD level decreased over time in the Lostine River stock but did not change for any of the other stocks. The data for BKD in Chinook salmon from northeast Oregon streams and hatcheries show that this disease is not prevalent and we found no evidence that the release of hatchery salmon is causing an increase in BKD prevalence in the monitored streams. However, we will continue to monitor this disease. Close

• 390. [Article] Stratigraphy and sedimentology of the middle eocene Cowlitz Formation and adjacent sedimentary and volcanic units in the Longview-Kelso area, southwest Washington

  Geologic mapping of the Longview-Kelso area and the measurement and description of a composite 650-meter thick stratigraphic section of the Cowlitz Formation (Tc) in Coal Creek using bio-, magneto-, litho-, ...

  Citation × Citation Citation Abstract Copy Title: Stratigraphy and sedimentology of the middle eocene Cowlitz Formation and adjacent sedimentary and volcanic units in the Longview-Kelso area, southwest Washington Author: McCutcheon, Mark S. Geologic mapping of the Longview-Kelso area and the measurement and description of a composite 650-meter thick stratigraphic section of the Cowlitz Formation (Tc) in Coal Creek using bio-, magneto-, litho-, and sequence stratigraphy reveals a complex interplay of Cowlitz micaceous, lithic arkosic shelf to tidal/estuarine to delta plain facies associations, and Grays River basalt lava flows and interbedded basalt volcaniclastics from nearby Grays River eruptive centers (e.g., Mt. Solo and Rocky Point). The lower 100 meters of the Coal Creek section (informal unit 1, Chron 18r) consists of micaceous, lithic arkosic sandstone and siltstone and minor coals, was deposited as part of a highstand system tract (HST) at the base of 3rd order cycle number 3. This unit consists of four dominantly tidal shoaling-upward arkosic sandstone parasequences reflecting upper shoreface to delta plain depositional environments. The overlying unit 2 (Chron 18n) is defined by abundant Grays River basalt volcaniclastic interbeds that intertongue with Cowlitz lithic arkoses. This unit represents the latter part of 3rd order cycle 3, and consists of mostly fining- and thinning-upward parasequences of middle shoreface to delta plain successions of an aggradational to transgressive parasequence set. Near the top of unit 2 is a maximum marine flooding surface depositing lower shoreface lithic arkosic sandstone to shelf siltstones over upper shoreface micaceous lithic arkose. Unit 3 comprises 3rd order cycle 4 (Chron 17r), a lowstand system tract, and consists of 6 mostly fining- and thinning-upward parasequences of lower shoreface to delta plain facies associations. A parasequence or erosional boundary at the base of unit 5 (Chron 17r) consists of submarine channel-fill scoured into underlying micaceous siltstones, produced during a lowstand system tract (LST) of 3rd order cycle 5. This deep marine channel-fill sequence is overlain by thinlybedded to laminated overbank distal turbidites and hemipelagic siltstones that define the top of the Coal Creek section. These 5 informal units in Coal Creek lithologically and chronologically correlate to 5 similar informal units defined by Payne (1998) in the type section of Cowlitz Formation in Olequa Creek near Vader -30 km to the north. Middle Eocene Grays River Volcanics of the study area are mapped as two separate units: a lower unit over 150 meters thick in places, consisting of subaerial basaltic flows and invasive flows (Tgvl), intrusions (Tgvis and Tgvid), and volcaniclastics (Tgvsl); and an upper unit consisting of commonly mollusk-bearing, shallow marine basaltic sedimentary interbeds that intertongue with the Cowlitz Formation (Tgvs2), particularly Cowlitz unit 2 of the Coal Creek section. These volcaniclastic deposits are intrabasinal, derived from volcanic highlands to the west and northwest, and local phreatomagmatic tuff cones. The lower Grays River volcaniclastic unit typically overlies Grays River flows in the study area and is divided into 5 informal facies. Geochemically, Grays River flows in the study area fall within normal parameters (3 to 4% TiO2 and high iron tholeiitic basalts). However, basalt flows and bedded scoriaceous breccias near Rocky Point are anomalously low in TiO2 and are considered in this study to be a separate volcanic subunit (Rocky Point Basalts), time equivalent to and interfingering with Grays River lavas, but may represent mixing with shallower western Cascade calc-alkaline magma. Over 60 younger Grays River dikes intrude the Cowlitz Formation in Coal Creek. A dike low in the Coal Creek section is dated at 40 ± 0.36 Ma, and an invasive flow at Mt. Solo is dated at 36.98 ±.78 Ma. Volcanics capping the hills east of the Cowlitz River are chemically distinct as slightly younger western Cascade basaltic andesite flows, and two dikes east of the river are chemically distinct as western Cascade andesite. Overlying Grays River Volcanics and Cowlitz Formation in much of the study area, are clayey and commonly tuffaceous siltstones and silty sandstones, possibly of the late Eocene-early Oligocene Toutle Formation, a new unit to this area. The Toutle Formation is a mixture of wave and stream reworked micaceous and arkosic Cowlitz Formation and fresh silicic pyroclastic ash and pumice from the active western Cascade arc. An angular unconformity separates the Paleogene Grays River Volcanics, Cowlitz Formation, and Toutle Formation from the early to middle Miocene Columbia River Basalt Group. Based on lithology, geochemistry, stratigraphic relationships, and magnetic polarity, 6 individual Columbia River Basalt flows have been mapped in this study. The three lower Grande Ronde flows are of normal polarity and Ortley low MgO chemical composition. The lowermost flow (N2 Ortley #1) is absent in the Columbia Heights area, low MgO, about 10 meters thick and consists of pillow-palagonite sequences in the upper quarry on Mt. Solo. Aphyric N2 Ortley flow #2 is over 35 meters thick with well-developed upper and lower colonnade, and of intermediate MgO. N2 Ortley flow #3 is pillow-palagonite in the Storedahl Quarry and low MgO. A -4-meter thick tuffaceous overbank siltstone and basalt conglomeratic channel interbed separates the three low MgO Ortley flows from the overlying high MgO N2 Grande Ronde Sentinel Bluffs flow. A single exposure of well-developed large colonnade with sparse 1 cm labradorite laths, and reddish oxidized soil, defines the N Sand Hollow flow of the Frenchman Springs Member of the Wanapum Formation. The overlying Pomona Member is mapped based on previous work by other authors. Pliocene gravels and arkosic sand of the Troutdale Formation form upland terrace deposits up to 100 meters thick in southern parts of the study area, and represent the uplifted paleo-thalweg and overbank flood deposits of the downcutting, antecedent ancestral Columbia River. Well-rounded clasts are a mixture of extrabasinal granitic and metamorphic quartzite, and intrabasinal porphyritic basaltic andesite, dacite, and basalt from the western Cascades and Columbia River Basalts. Troutdale terrace gravels grade northward into contemporaneous volcanic pebble and cobble gravel terrace deposits produced along the ancestral Cowlitz River that are dominantly composed of porphyritic andesite gravel and volcanic sand from the western Cascades. Lower terraces along the Cowlitz River were deposited by the late Pleistocene Missoula Floods. All of these unconsolidated to semiconsolidated gravels and sands are prone to landslides, and the Aldercrest-Banyon landslide, the second worst landslide disaster in American history, occurred in the Troutdale Formation gravels. After eruption of the Grays River Volcanics and deposition of the Cowlitz Formation, the forearc underwent a period of transtension in the late-middle Eocene related to magmatic upwelling and reorganization of the subducting Farallon Plate. This event produced a northwest-trending set of oblique slip normal faults, along which Grays River dikes intruded. Starting in the early Miocene the region underwent a transpressional event, reactivating many of the northwest-trending faults, and producing the Columbia Heights Anticline, Hazel Dell Syncline, the Coal Creek Fault, and the Kelso Fault Zone. The paleotopography resulting from this event was stream eroded to a nearly flat plain before emplacement of the Columbia River Basalts, which are nearly horizontal today. Continued offset along the northwest-trending fault set has also offset the Columbia River Basalts. Continued oblique slip post-Miocene broad arching of the Coast Range and downcutting by the Columbia and Cowlitz Rivers has resulted in Pliocene and Pleistocene terraces, and produced an east-west fault set that offsets all earlier structural features. Title: Stratigraphy and sedimentology of the middle eocene Cowlitz Formation and adjacent sedimentary and volcanic units in the Longview-Kelso area, southwest Washington Author: McCutcheon, Mark S. Geologic mapping of the Longview-Kelso area and the measurement and description of a composite 650-meter thick stratigraphic section of the Cowlitz Formation (Tc) in Coal Creek using bio-, magneto-, litho-, and sequence stratigraphy reveals a complex interplay of Cowlitz micaceous, lithic arkosic shelf to tidal/estuarine to delta plain facies associations, and Grays River basalt lava flows and interbedded basalt volcaniclastics from nearby Grays River eruptive centers (e.g., Mt. Solo and Rocky Point). The lower 100 meters of the Coal Creek section (informal unit 1, Chron 18r) consists of micaceous, lithic arkosic sandstone and siltstone and minor coals, was deposited as part of a highstand system tract (HST) at the base of 3rd order cycle number 3. This unit consists of four dominantly tidal shoaling-upward arkosic sandstone parasequences reflecting upper shoreface to delta plain depositional environments. The overlying unit 2 (Chron 18n) is defined by abundant Grays River basalt volcaniclastic interbeds that intertongue with Cowlitz lithic arkoses. This unit represents the latter part of 3rd order cycle 3, and consists of mostly fining- and thinning-upward parasequences of middle shoreface to delta plain successions of an aggradational to transgressive parasequence set. Near the top of unit 2 is a maximum marine flooding surface depositing lower shoreface lithic arkosic sandstone to shelf siltstones over upper shoreface micaceous lithic arkose. Unit 3 comprises 3rd order cycle 4 (Chron 17r), a lowstand system tract, and consists of 6 mostly fining- and thinning-upward parasequences of lower shoreface to delta plain facies associations. A parasequence or erosional boundary at the base of unit 5 (Chron 17r) consists of submarine channel-fill scoured into underlying micaceous siltstones, produced during a lowstand system tract (LST) of 3rd order cycle 5. This deep marine channel-fill sequence is overlain by thinlybedded to laminated overbank distal turbidites and hemipelagic siltstones that define the top of the Coal Creek section. These 5 informal units in Coal Creek lithologically and chronologically correlate to 5 similar informal units defined by Payne (1998) in the type section of Cowlitz Formation in Olequa Creek near Vader -30 km to the north. Middle Eocene Grays River Volcanics of the study area are mapped as two separate units: a lower unit over 150 meters thick in places, consisting of subaerial basaltic flows and invasive flows (Tgvl), intrusions (Tgvis and Tgvid), and volcaniclastics (Tgvsl); and an upper unit consisting of commonly mollusk-bearing, shallow marine basaltic sedimentary interbeds that intertongue with the Cowlitz Formation (Tgvs2), particularly Cowlitz unit 2 of the Coal Creek section. These volcaniclastic deposits are intrabasinal, derived from volcanic highlands to the west and northwest, and local phreatomagmatic tuff cones. The lower Grays River volcaniclastic unit typically overlies Grays River flows in the study area and is divided into 5 informal facies. Geochemically, Grays River flows in the study area fall within normal parameters (3 to 4% TiO2 and high iron tholeiitic basalts). However, basalt flows and bedded scoriaceous breccias near Rocky Point are anomalously low in TiO2 and are considered in this study to be a separate volcanic subunit (Rocky Point Basalts), time equivalent to and interfingering with Grays River lavas, but may represent mixing with shallower western Cascade calc-alkaline magma. Over 60 younger Grays River dikes intrude the Cowlitz Formation in Coal Creek. A dike low in the Coal Creek section is dated at 40 ± 0.36 Ma, and an invasive flow at Mt. Solo is dated at 36.98 ±.78 Ma. Volcanics capping the hills east of the Cowlitz River are chemically distinct as slightly younger western Cascade basaltic andesite flows, and two dikes east of the river are chemically distinct as western Cascade andesite. Overlying Grays River Volcanics and Cowlitz Formation in much of the study area, are clayey and commonly tuffaceous siltstones and silty sandstones, possibly of the late Eocene-early Oligocene Toutle Formation, a new unit to this area. The Toutle Formation is a mixture of wave and stream reworked micaceous and arkosic Cowlitz Formation and fresh silicic pyroclastic ash and pumice from the active western Cascade arc. An angular unconformity separates the Paleogene Grays River Volcanics, Cowlitz Formation, and Toutle Formation from the early to middle Miocene Columbia River Basalt Group. Based on lithology, geochemistry, stratigraphic relationships, and magnetic polarity, 6 individual Columbia River Basalt flows have been mapped in this study. The three lower Grande Ronde flows are of normal polarity and Ortley low MgO chemical composition. The lowermost flow (N2 Ortley #1) is absent in the Columbia Heights area, low MgO, about 10 meters thick and consists of pillow-palagonite sequences in the upper quarry on Mt. Solo. Aphyric N2 Ortley flow #2 is over 35 meters thick with well-developed upper and lower colonnade, and of intermediate MgO. N2 Ortley flow #3 is pillow-palagonite in the Storedahl Quarry and low MgO. A -4-meter thick tuffaceous overbank siltstone and basalt conglomeratic channel interbed separates the three low MgO Ortley flows from the overlying high MgO N2 Grande Ronde Sentinel Bluffs flow. A single exposure of well-developed large colonnade with sparse 1 cm labradorite laths, and reddish oxidized soil, defines the N Sand Hollow flow of the Frenchman Springs Member of the Wanapum Formation. The overlying Pomona Member is mapped based on previous work by other authors. Pliocene gravels and arkosic sand of the Troutdale Formation form upland terrace deposits up to 100 meters thick in southern parts of the study area, and represent the uplifted paleo-thalweg and overbank flood deposits of the downcutting, antecedent ancestral Columbia River. Well-rounded clasts are a mixture of extrabasinal granitic and metamorphic quartzite, and intrabasinal porphyritic basaltic andesite, dacite, and basalt from the western Cascades and Columbia River Basalts. Troutdale terrace gravels grade northward into contemporaneous volcanic pebble and cobble gravel terrace deposits produced along the ancestral Cowlitz River that are dominantly composed of porphyritic andesite gravel and volcanic sand from the western Cascades. Lower terraces along the Cowlitz River were deposited by the late Pleistocene Missoula Floods. All of these unconsolidated to semiconsolidated gravels and sands are prone to landslides, and the Aldercrest-Banyon landslide, the second worst landslide disaster in American history, occurred in the Troutdale Formation gravels. After eruption of the Grays River Volcanics and deposition of the Cowlitz Formation, the forearc underwent a period of transtension in the late-middle Eocene related to magmatic upwelling and reorganization of the subducting Farallon Plate. This event produced a northwest-trending set of oblique slip normal faults, along which Grays River dikes intruded. Starting in the early Miocene the region underwent a transpressional event, reactivating many of the northwest-trending faults, and producing the Columbia Heights Anticline, Hazel Dell Syncline, the Coal Creek Fault, and the Kelso Fault Zone. The paleotopography resulting from this event was stream eroded to a nearly flat plain before emplacement of the Columbia River Basalts, which are nearly horizontal today. Continued offset along the northwest-trending fault set has also offset the Columbia River Basalts. Continued oblique slip post-Miocene broad arching of the Coast Range and downcutting by the Columbia and Cowlitz Rivers has resulted in Pliocene and Pleistocene terraces, and produced an east-west fault set that offsets all earlier structural features. Close