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• 2351. [Article] Stratigraphy, structure, and natural gas potential of tertiary sedimentary and volcanic units, Clatskanie 7.5 minute quadrangle, Northwest Oregon

  The geology and natural gas potential of the Clatskanie 7.5-minute quadrangle in Columbia County, Oregon was studied utilizing a combination of geologic mapping, measuring of stratigraphic sections, diatom ...

  Citation × Citation Citation Abstract Copy Title: Stratigraphy, structure, and natural gas potential of tertiary sedimentary and volcanic units, Clatskanie 7.5 minute quadrangle, Northwest Oregon Author: Eriksson, Andrew The geology and natural gas potential of the Clatskanie 7.5-minute quadrangle in Columbia County, Oregon was studied utilizing a combination of geologic mapping, measuring of stratigraphic sections, diatom and molluscan fossil identifications, with subsurface geophysical data and petrographic and geochemical analyses. The stratigraphy of the study area consists of two Tertiary volcanic units (Grays River Volcanics and Columbia River Basalt Group) and four sedimentary units (Cowlitz (subsurface) Keasey, Pittsburg Bluff, and Scappoose formations) that were deposited in the Nehalem forearc basin. The major structure of the area is defined by the oblique-slip Scappoose-Clatskanie fault with both normal and dextral motion. In the east-central part of the study area, this post-Miocene fault zone, formed by a right step over in a right-lateral strike-slip system, created an extensional zone with abundant normal faulting (horsts and grabens). The faulting uplifted an isolated block of middle Eocene Grays River Volcanics subaerial flows against downdropped Miocene Columbia River Basalt in the northwestern part of the map area near the town of Clatskanie along Highway 30. This block was part of a major Grays River Volcanics paleohigh (herein named the Clatskanie High) and forms part of a regional gravity/magnetic high beneath the Columbia river. The Clatskanie High and the Windy Ridge High (subsurfance paleohigh also composed of Grays River Volcanics) in the central to southern part of the study area, restricted deposition and caused onlapping of the Cowlitz, Keasey, and Pittsburg Bluff formations. The Clatskanie High shield volcano defines the northern boundary of the Mist Gas Field. In addition, local unconformities at the base of the Keasey and Pittsburg Bluff formations progressively truncate the Cowlitz C&W sandstone reservoir and upper mudstone seal to the north. The largely unexplored central and northeastern parts of the study area near the Scappoose-Clatskanie fault zone with horst and grabens and stratigraphic pinchouts represent some of the most promising untested exploration plays in the quadrangle. Associated wtih the Clatskanie High are two new (informal) members of the Oligocene Pittsburg Bluff Formation that are defined and mapped by this study. The Conyers Creek member (informal) is a shallow-marine mollusk-bearing pebbly-basaltic litharenite (a poorly sorted nearshore to shoreface sandstone) with an interbedded fossiliferous fine pebble conglomerate of Grays River volcanic clasts. The lens-like nearshore unit was deposited on the margins of the uplifted Grays River basaltic oceanic island and, thus, restricted to an area around the paleohigh. Locally overlying the Conyers Creek member and interbedded with the East Fork member (Pittsburg Bluff Formation) is the Clatskanie Conglomerate member (the second informal member defined by this study). The 180 feet (55 meter) thick member consists of a basal, clast-supported 110 feet (33 meter) thick polymict conglomerate and upper well-consolidated 70 feet (21 meter) think micaceous arkosic sandstone. The Clatskanie Conglomerate is a lens-like fluvial deposit in the northwestern part of the study area, possibly syndepositional and restricted in deposition to the center of a growing syncline. The cobble to boulder sized clasts of quartzite, chert, metamorphics, and andesites/dacites indicate extrabasinal sources such as the Western Cascades arc and continental sources in eastern Oregon, Idaho, Montana, and eastern Washington via an ancestral Columbia River drainage system. The diatom-bearing tuffaceous clayey siltstone of the Keasey Formation and the mollusk-bearing sandy siltstone of the East Fork member (Pittsburg Bluff Formation) formed in continental slope and middle to outer shelf environments. Extensive explosive dacitic eruptions in the nearby Western Cascade arc contributed abundant ash, which washed into the forearc basin. Local Thyosira chemosynthetic pelecypods and calcareous concretionary beds indicate the local presence of either cold methane seeps or a gas hydrate system on the Pittsburg Bluff continental shelf. The Scappoose Formation consists predominantly of a basal basalt and siltstone rip-up conglomerate deposited in an incised valley during a low stand systems tract (LST). The conglomerate is overlain by a diatom-bearing shallow-marine tuffaceous siltstone of a transgressive and highstand systems tracts (TST & HST), and capped by a cross-bedded fluvial lithic arkosic sandstone of a second lowstand systems tract (LST). Chemical analysis of the basal basalt conglomerate clasts indicate that they were derived from erosion of high TiO2R2 Wapshilla Ridge flow unit of the Grande Ronde Basalt (16.5 to 15.6 Ma) of the lower to middle Miocene Columbia River Basalt Group. The Scappoose Formation also includes thin fluvial and lacustrine sandstones and tuffs interbedded with Columbia River Basalt flows. Capping these Tertiary units are three units of low-MgO Grande Ronde Basalt of the Columbia River Basalt Group. These include 1-2 basal aphyric flow(s) of the high-TiO2R2 Wapshilla Ridge flow unit, at least six flows (some invasive) of the R2 low-TiO2 Grouse Creek flow unit, and the upper sparsely glomerophyric flows of N2 Winter Water flow unit. The structural history of the region is characterized by two major tectonic events. A late Eocene extensional period prior to deposition of the Keasey Formation created normal faulting (horsts and grabens) throughout the Cowlitz Formation. These faults formed most of the structural traps in the Mist Gas Field including those drilled by producing wells in the southern part of the quadrangle near the Windy Ridge High. The post-Miocene episode was dominated by wrench fault tectonics that manifested as strike-slip oblique-slip motion on dominant northwest-trending and subordinate northeast-trending faults in the Columbia River Basalt Group flows. Title: Stratigraphy, structure, and natural gas potential of tertiary sedimentary and volcanic units, Clatskanie 7.5 minute quadrangle, Northwest Oregon Author: Eriksson, Andrew The geology and natural gas potential of the Clatskanie 7.5-minute quadrangle in Columbia County, Oregon was studied utilizing a combination of geologic mapping, measuring of stratigraphic sections, diatom and molluscan fossil identifications, with subsurface geophysical data and petrographic and geochemical analyses. The stratigraphy of the study area consists of two Tertiary volcanic units (Grays River Volcanics and Columbia River Basalt Group) and four sedimentary units (Cowlitz (subsurface) Keasey, Pittsburg Bluff, and Scappoose formations) that were deposited in the Nehalem forearc basin. The major structure of the area is defined by the oblique-slip Scappoose-Clatskanie fault with both normal and dextral motion. In the east-central part of the study area, this post-Miocene fault zone, formed by a right step over in a right-lateral strike-slip system, created an extensional zone with abundant normal faulting (horsts and grabens). The faulting uplifted an isolated block of middle Eocene Grays River Volcanics subaerial flows against downdropped Miocene Columbia River Basalt in the northwestern part of the map area near the town of Clatskanie along Highway 30. This block was part of a major Grays River Volcanics paleohigh (herein named the Clatskanie High) and forms part of a regional gravity/magnetic high beneath the Columbia river. The Clatskanie High and the Windy Ridge High (subsurfance paleohigh also composed of Grays River Volcanics) in the central to southern part of the study area, restricted deposition and caused onlapping of the Cowlitz, Keasey, and Pittsburg Bluff formations. The Clatskanie High shield volcano defines the northern boundary of the Mist Gas Field. In addition, local unconformities at the base of the Keasey and Pittsburg Bluff formations progressively truncate the Cowlitz C&W sandstone reservoir and upper mudstone seal to the north. The largely unexplored central and northeastern parts of the study area near the Scappoose-Clatskanie fault zone with horst and grabens and stratigraphic pinchouts represent some of the most promising untested exploration plays in the quadrangle. Associated wtih the Clatskanie High are two new (informal) members of the Oligocene Pittsburg Bluff Formation that are defined and mapped by this study. The Conyers Creek member (informal) is a shallow-marine mollusk-bearing pebbly-basaltic litharenite (a poorly sorted nearshore to shoreface sandstone) with an interbedded fossiliferous fine pebble conglomerate of Grays River volcanic clasts. The lens-like nearshore unit was deposited on the margins of the uplifted Grays River basaltic oceanic island and, thus, restricted to an area around the paleohigh. Locally overlying the Conyers Creek member and interbedded with the East Fork member (Pittsburg Bluff Formation) is the Clatskanie Conglomerate member (the second informal member defined by this study). The 180 feet (55 meter) thick member consists of a basal, clast-supported 110 feet (33 meter) thick polymict conglomerate and upper well-consolidated 70 feet (21 meter) think micaceous arkosic sandstone. The Clatskanie Conglomerate is a lens-like fluvial deposit in the northwestern part of the study area, possibly syndepositional and restricted in deposition to the center of a growing syncline. The cobble to boulder sized clasts of quartzite, chert, metamorphics, and andesites/dacites indicate extrabasinal sources such as the Western Cascades arc and continental sources in eastern Oregon, Idaho, Montana, and eastern Washington via an ancestral Columbia River drainage system. The diatom-bearing tuffaceous clayey siltstone of the Keasey Formation and the mollusk-bearing sandy siltstone of the East Fork member (Pittsburg Bluff Formation) formed in continental slope and middle to outer shelf environments. Extensive explosive dacitic eruptions in the nearby Western Cascade arc contributed abundant ash, which washed into the forearc basin. Local Thyosira chemosynthetic pelecypods and calcareous concretionary beds indicate the local presence of either cold methane seeps or a gas hydrate system on the Pittsburg Bluff continental shelf. The Scappoose Formation consists predominantly of a basal basalt and siltstone rip-up conglomerate deposited in an incised valley during a low stand systems tract (LST). The conglomerate is overlain by a diatom-bearing shallow-marine tuffaceous siltstone of a transgressive and highstand systems tracts (TST & HST), and capped by a cross-bedded fluvial lithic arkosic sandstone of a second lowstand systems tract (LST). Chemical analysis of the basal basalt conglomerate clasts indicate that they were derived from erosion of high TiO2R2 Wapshilla Ridge flow unit of the Grande Ronde Basalt (16.5 to 15.6 Ma) of the lower to middle Miocene Columbia River Basalt Group. The Scappoose Formation also includes thin fluvial and lacustrine sandstones and tuffs interbedded with Columbia River Basalt flows. Capping these Tertiary units are three units of low-MgO Grande Ronde Basalt of the Columbia River Basalt Group. These include 1-2 basal aphyric flow(s) of the high-TiO2R2 Wapshilla Ridge flow unit, at least six flows (some invasive) of the R2 low-TiO2 Grouse Creek flow unit, and the upper sparsely glomerophyric flows of N2 Winter Water flow unit. The structural history of the region is characterized by two major tectonic events. A late Eocene extensional period prior to deposition of the Keasey Formation created normal faulting (horsts and grabens) throughout the Cowlitz Formation. These faults formed most of the structural traps in the Mist Gas Field including those drilled by producing wells in the southern part of the quadrangle near the Windy Ridge High. The post-Miocene episode was dominated by wrench fault tectonics that manifested as strike-slip oblique-slip motion on dominant northwest-trending and subordinate northeast-trending faults in the Columbia River Basalt Group flows. 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• 2352. [Article] The effect of fertilizer treatments on oil content and nutrient concentration of peppermint in western Oregon

  During the summer of 1967 a fertilizer survey was conducted to determine the nutrient status of peppermint fields, the nutrient concentration of plant tissue and the oil content of peppermint in Oregon. Plant ...

  Citation × Citation Citation Abstract Copy Title: The effect of fertilizer treatments on oil content and nutrient concentration of peppermint in western Oregon Author: Huettig, Myron Allen During the summer of 1967 a fertilizer survey was conducted to determine the nutrient status of peppermint fields, the nutrient concentration of plant tissue and the oil content of peppermint in Oregon. Plant and soil samples and the field's fertilizer history were collected from cooperators in Oregon's peppermint growing areas in June. Oil samples and plant samples were collected in August and September. Results of the survey indicated the following: (1) Micronutrient levels of the plant tissue were relatively high and the highest Mn concentrations were associated with lower oil concentrations. (2) The highest levels of total nitrogen in the leaf analyses were associated with lower oil concentrations. The higher N levels appeared to be related to fields with rank stemmy growth. (3) All P levels were quite high and there were no apparent associations between P concentration and oil concentration. (4) There was an antagonistic relationship between K and Na concentration within the plant and the higher oil concentrations were associated with moderate levels of both K and Na in the plant. (5) The majority of the oil is located within the top 15 inches of the plant. The results indicated major emphasis of field experiments should be placed on time and rate of N application and the Na-K relationship. Since P is a major fertilizer expenditure for many growers, P should be included in the over-all nutrient evaluation. Five experiments were established in the spring of 1968 to evaluate the effects of N, P, K and Na fertilizers on the oil content and nutrient concentration of peppermint in western Oregon. Nitrogen experiments were located south of Junction City (Harper) and west of Grants Pass (N-Fry) while P, K and Na experiments were located west of Jefferson (Stauble), north of Corvallis (Belnap) and west of Grants Pass (K-Fry). The N experiments were randomized blocks with four replications. Seven rates of N were used in combination with five application dates. The P, K and Na experiments were randomized blocks with three replications. Four rates of K were applied with and without Na. Phosphorus was applied to all but two treatments. Plant samples were collected June 25-27 at all locations and plant and oil samples were collected at harvest. The plant sample consisted of the main stem from the latest matured leaves at the top of the plant down the stem six inches. The Stauble location was sampled every two weeks during the growing season and both the stems and the mature leaves on the sampled stem portion were collected. P, K, Na, Mn, Ca and Mg were determined on the June samples while NO₃-N and Cl were determined on the harvest sam- ples and NO₃-N on the June samples of the N experiments. Oil samples of about five pounds of green plant material were taken from the center of each plot. The sample was placed on a wire screen and dried either in the field or the greenhouse. After the samples had dried for two to three days, they were placed in a cotton bag and were ready for distillation. A portable still designed after commercial stills was used to remove the oil from the hay. Increasing rates of N increased the NO₃-N concentration of peppermint stems and the oil content of the plants. Delayed application of N did not affect the NO₃-N concentration of the plants at a given rate of N at harvest. However, delayed application did increase the percent oil and total oil yield. The July 1 application date had a significantly higher percent oil and total oil yield than the June 1 date. Yield of hay increased significantly to about the 250 pound rate and subsequently decreased with higher N application. Delayed N application decreased the hay yield. Phosphorus fertilization did not increase the P concentration at any of the locations nor did it have any effect on the oil content. P concentration ranged from .31 - .49 percent in the stem sample taken June 25-27. Potassium fertilization increased the K concentration of peppermint with the greatest increase occurring where the soil had a low K soil test. However, K fertilization did not affect the oil content. K concentration of the June stem sample varied from 2.5 to 6.1 percent.. Application of Na increased the Na concentration at all locations where Na was applied. Sodium fertilization significantly increased the percent oil at the Stauble location and increased the percent oil at the K- Fay location. Hay yield was not affected by Na. There was a considerable amount of variation in the oil and NO₃-N analysis for all experiments. The coefficient of variation for NO₃-N analysis was 37.9 and 38.7 percent for N-Fry and Harper respectively and 89 percent for Stauble. The coefficient of variation for percent oil was 14.0, 20.6, 21.7 and 14.3 percent for N-Fry, Harper, Stauble and K-Fry respectively. Since there was a large variability in the oil data, an experiment was designed to evaluate the effectiveness of the method of handling the oil samples. Four samples, similar in size, were taken from peppermint variety trials that were established on uniform, first year row mint. Drying and distillation were the same as described for the other oil samples. There were no significant differences among the distillation units and the coefficient of varia- tion was 7.1 percent.. It was concluded that reproducible results could be obtained for oil analysis when uniform plant material was used. Title: The effect of fertilizer treatments on oil content and nutrient concentration of peppermint in western Oregon Author: Huettig, Myron Allen During the summer of 1967 a fertilizer survey was conducted to determine the nutrient status of peppermint fields, the nutrient concentration of plant tissue and the oil content of peppermint in Oregon. Plant and soil samples and the field's fertilizer history were collected from cooperators in Oregon's peppermint growing areas in June. Oil samples and plant samples were collected in August and September. Results of the survey indicated the following: (1) Micronutrient levels of the plant tissue were relatively high and the highest Mn concentrations were associated with lower oil concentrations. (2) The highest levels of total nitrogen in the leaf analyses were associated with lower oil concentrations. The higher N levels appeared to be related to fields with rank stemmy growth. (3) All P levels were quite high and there were no apparent associations between P concentration and oil concentration. (4) There was an antagonistic relationship between K and Na concentration within the plant and the higher oil concentrations were associated with moderate levels of both K and Na in the plant. (5) The majority of the oil is located within the top 15 inches of the plant. The results indicated major emphasis of field experiments should be placed on time and rate of N application and the Na-K relationship. Since P is a major fertilizer expenditure for many growers, P should be included in the over-all nutrient evaluation. Five experiments were established in the spring of 1968 to evaluate the effects of N, P, K and Na fertilizers on the oil content and nutrient concentration of peppermint in western Oregon. Nitrogen experiments were located south of Junction City (Harper) and west of Grants Pass (N-Fry) while P, K and Na experiments were located west of Jefferson (Stauble), north of Corvallis (Belnap) and west of Grants Pass (K-Fry). The N experiments were randomized blocks with four replications. Seven rates of N were used in combination with five application dates. The P, K and Na experiments were randomized blocks with three replications. Four rates of K were applied with and without Na. Phosphorus was applied to all but two treatments. Plant samples were collected June 25-27 at all locations and plant and oil samples were collected at harvest. The plant sample consisted of the main stem from the latest matured leaves at the top of the plant down the stem six inches. The Stauble location was sampled every two weeks during the growing season and both the stems and the mature leaves on the sampled stem portion were collected. P, K, Na, Mn, Ca and Mg were determined on the June samples while NO₃-N and Cl were determined on the harvest sam- ples and NO₃-N on the June samples of the N experiments. Oil samples of about five pounds of green plant material were taken from the center of each plot. The sample was placed on a wire screen and dried either in the field or the greenhouse. After the samples had dried for two to three days, they were placed in a cotton bag and were ready for distillation. A portable still designed after commercial stills was used to remove the oil from the hay. Increasing rates of N increased the NO₃-N concentration of peppermint stems and the oil content of the plants. Delayed application of N did not affect the NO₃-N concentration of the plants at a given rate of N at harvest. However, delayed application did increase the percent oil and total oil yield. The July 1 application date had a significantly higher percent oil and total oil yield than the June 1 date. Yield of hay increased significantly to about the 250 pound rate and subsequently decreased with higher N application. Delayed N application decreased the hay yield. Phosphorus fertilization did not increase the P concentration at any of the locations nor did it have any effect on the oil content. P concentration ranged from .31 - .49 percent in the stem sample taken June 25-27. Potassium fertilization increased the K concentration of peppermint with the greatest increase occurring where the soil had a low K soil test. However, K fertilization did not affect the oil content. K concentration of the June stem sample varied from 2.5 to 6.1 percent.. Application of Na increased the Na concentration at all locations where Na was applied. Sodium fertilization significantly increased the percent oil at the Stauble location and increased the percent oil at the K- Fay location. Hay yield was not affected by Na. There was a considerable amount of variation in the oil and NO₃-N analysis for all experiments. The coefficient of variation for NO₃-N analysis was 37.9 and 38.7 percent for N-Fry and Harper respectively and 89 percent for Stauble. The coefficient of variation for percent oil was 14.0, 20.6, 21.7 and 14.3 percent for N-Fry, Harper, Stauble and K-Fry respectively. Since there was a large variability in the oil data, an experiment was designed to evaluate the effectiveness of the method of handling the oil samples. Four samples, similar in size, were taken from peppermint variety trials that were established on uniform, first year row mint. Drying and distillation were the same as described for the other oil samples. There were no significant differences among the distillation units and the coefficient of varia- tion was 7.1 percent.. It was concluded that reproducible results could be obtained for oil analysis when uniform plant material was used. Close

• 2353. [Article] Factors affecting within-season and between-season breeding dispersal of burrowing owls in California

  Dispersal is integral to our understanding of the life history and population biology of many vertebrates, but difficulties in detecting long distance movements have complicated its study. Moreover, studies ...

  Citation × Citation Citation Abstract Copy Title: Factors affecting within-season and between-season breeding dispersal of burrowing owls in California Author: Catlin, Daniel H. Dispersal is integral to our understanding of the life history and population biology of many vertebrates, but difficulties in detecting long distance movements have complicated its study. Moreover, studies of factors affecting dispersal are often unable to determine the relative contributions of variables such as nesting success, mate fidelity, and nest site fidelity. I examined the effects of nest depredation on dispersal in comparison to successful nests and nests that failed for other reasons. Additionally, I investigated a suite of biological factors affecting within-season and between-season breeding dispersal by burrowing owls (Athene cunicularia) in California, attempting to partition the effects of these covariates and to deal with long distance detectibility issues. For both types of dispersal, I divided dispersal into two components; dispersal probability and dispersal distance. I used experimental and observational approaches to investigate within-season dispersal in two contrasting environments; a large grassland and an agricultural landscape. I found that the factors affecting dispersal probability and dispersal distance were different, supporting my decision to examine each separately. Of the factors investigated, dispersal probability was influenced most by study area, mate fidelity, and nesting success. The proportion of individuals dispersing tended to be greater for owls that lost their mate due to death or dispersal (60%, 6 of 10) and owls whose nests were depredated (50%, 10 of 20) than for owls that did not lose their mates (33%, 6 of 18) and owls whose nests were successful (17%, 1 of 6), respectively. The results from an experiment where we removed eggs from pairs of owls to simulate nest depredation were consistent with the observational results, suggesting that owls whose nests were depredated may have been more likely to disperse than control owls. The reactions of owls from depredated nests, however, did not appear to differ from those whose nests failed for other reasons. In contrast, owl dispersal distance was most affected by owl gender, and to a lesser degree by study area and nesting success. Dispersal distance was greater for female owls (median = 1575 m, n = 13) than male owls (median = 417 m, n = 11), greater for owls from the grassland area (median= 939 m, n = 9) compared to owls from the agricultural area (median = 829 m, n = 15), and greater for owls whose nests had failed (median = 1018 m, n = 17) than for owls that successfully bred (median 475 m, n = 7). Nest depredation, however, did not appear to increase dispersal distance. The geometric models performed poorly at approximating within-season dispersal distance, indicating that many owls disperse farther than predicted by a "first is best" model. I speculate that the distribution of within-season dispersal distances by burrowing owls is related to the densities of suitable territories and mates, which are more variable than predicted by a geometric model within a breeding season. I used data from band resightings and nesting success (1998-2003) to examine factors related to between-season breeding dispersal by burrowing owls in an agricultural environment. Of the factors investigated, nesting success appeared to have the greatest effect on burrowing owl dispersal. The proportion of individuals dispersing was greater for owls whose nests had failed (68%, 28 of 41) than owls whose nests were successful (27%, 58 of 212). Similarly, dispersal distance was greater for owls whose nest failed (mean = 745 ± 175 m, n = 28) than owls with successful nests (mean = 340 ± 36 m,n = 58). The owls exhibited high rates of nest site and mate fidelity between breeding seasons. There was evidence that previous experience at a breeding site may have reduced dispersal probability and that unpaired owls may have been more likely to disperse and dispersed slightly greater distances than those that retained their mates. Nesting success, however, appeared to be the major factor contributing to burrowing owl breeding dispersal after controlling for nest site and mate fidelity, particularly for male owls. Despite the complexity of the dispersal process, a geometric model provided a reasonably good fit to the distribution of between-season breeding dispersal distances at relatively short distances, but failed to predict a small percentage of long distance dispersals. Geometric models appeared to be a better fit for the distribution of between-season breeding dispersal distances than within-season breeding dispersal distances. Factors affecting within-season dispersal were generally similar to those affecting between-season dispersal. Both within-season and between-season breeding dispersal were affected by nesting success and mate fidelity, but the effects of these factors differed between the two types of breeding dispersal, suggesting that time constraints and competition play a larger role in within-season dispersal than between season dispersal. In addition, both studies supported a difference in dispersal behavior, in which the factors that affected dispersal probability were distinct from those that affected dispersal distance. These results help determine the relative contributions of nesting success, mate fidelity, and nest site fidelity to avian dispersal, offer some evidence that the effects of nest depredation are not distinct from the effects of nest failure in general, and provide further support for the division of dispersal into dispersal probability and dispersal distance. Title: Factors affecting within-season and between-season breeding dispersal of burrowing owls in California Author: Catlin, Daniel H. Dispersal is integral to our understanding of the life history and population biology of many vertebrates, but difficulties in detecting long distance movements have complicated its study. Moreover, studies of factors affecting dispersal are often unable to determine the relative contributions of variables such as nesting success, mate fidelity, and nest site fidelity. I examined the effects of nest depredation on dispersal in comparison to successful nests and nests that failed for other reasons. Additionally, I investigated a suite of biological factors affecting within-season and between-season breeding dispersal by burrowing owls (Athene cunicularia) in California, attempting to partition the effects of these covariates and to deal with long distance detectibility issues. For both types of dispersal, I divided dispersal into two components; dispersal probability and dispersal distance. I used experimental and observational approaches to investigate within-season dispersal in two contrasting environments; a large grassland and an agricultural landscape. I found that the factors affecting dispersal probability and dispersal distance were different, supporting my decision to examine each separately. Of the factors investigated, dispersal probability was influenced most by study area, mate fidelity, and nesting success. The proportion of individuals dispersing tended to be greater for owls that lost their mate due to death or dispersal (60%, 6 of 10) and owls whose nests were depredated (50%, 10 of 20) than for owls that did not lose their mates (33%, 6 of 18) and owls whose nests were successful (17%, 1 of 6), respectively. The results from an experiment where we removed eggs from pairs of owls to simulate nest depredation were consistent with the observational results, suggesting that owls whose nests were depredated may have been more likely to disperse than control owls. The reactions of owls from depredated nests, however, did not appear to differ from those whose nests failed for other reasons. In contrast, owl dispersal distance was most affected by owl gender, and to a lesser degree by study area and nesting success. Dispersal distance was greater for female owls (median = 1575 m, n = 13) than male owls (median = 417 m, n = 11), greater for owls from the grassland area (median= 939 m, n = 9) compared to owls from the agricultural area (median = 829 m, n = 15), and greater for owls whose nests had failed (median = 1018 m, n = 17) than for owls that successfully bred (median 475 m, n = 7). Nest depredation, however, did not appear to increase dispersal distance. The geometric models performed poorly at approximating within-season dispersal distance, indicating that many owls disperse farther than predicted by a "first is best" model. I speculate that the distribution of within-season dispersal distances by burrowing owls is related to the densities of suitable territories and mates, which are more variable than predicted by a geometric model within a breeding season. I used data from band resightings and nesting success (1998-2003) to examine factors related to between-season breeding dispersal by burrowing owls in an agricultural environment. Of the factors investigated, nesting success appeared to have the greatest effect on burrowing owl dispersal. The proportion of individuals dispersing was greater for owls whose nests had failed (68%, 28 of 41) than owls whose nests were successful (27%, 58 of 212). Similarly, dispersal distance was greater for owls whose nest failed (mean = 745 ± 175 m, n = 28) than owls with successful nests (mean = 340 ± 36 m,n = 58). The owls exhibited high rates of nest site and mate fidelity between breeding seasons. There was evidence that previous experience at a breeding site may have reduced dispersal probability and that unpaired owls may have been more likely to disperse and dispersed slightly greater distances than those that retained their mates. Nesting success, however, appeared to be the major factor contributing to burrowing owl breeding dispersal after controlling for nest site and mate fidelity, particularly for male owls. Despite the complexity of the dispersal process, a geometric model provided a reasonably good fit to the distribution of between-season breeding dispersal distances at relatively short distances, but failed to predict a small percentage of long distance dispersals. Geometric models appeared to be a better fit for the distribution of between-season breeding dispersal distances than within-season breeding dispersal distances. Factors affecting within-season dispersal were generally similar to those affecting between-season dispersal. Both within-season and between-season breeding dispersal were affected by nesting success and mate fidelity, but the effects of these factors differed between the two types of breeding dispersal, suggesting that time constraints and competition play a larger role in within-season dispersal than between season dispersal. In addition, both studies supported a difference in dispersal behavior, in which the factors that affected dispersal probability were distinct from those that affected dispersal distance. These results help determine the relative contributions of nesting success, mate fidelity, and nest site fidelity to avian dispersal, offer some evidence that the effects of nest depredation are not distinct from the effects of nest failure in general, and provide further support for the division of dispersal into dispersal probability and dispersal distance. Close

• 2354. [Article] Mixed-Severity Fire Effects on Biological Legacies and Vegetation Response in Pseudotsuga Forests of Western Oregon's Central Cascades, USA

  Mixed-severity fire occurrence is increasingly recognized in Pseudotsuga forests of the Pacific Northwest, but questions remain about how tree mortality varies, and forest structure is altered, across ...

  Citation × Citation Citation Abstract Copy Title: Mixed-Severity Fire Effects on Biological Legacies and Vegetation Response in Pseudotsuga Forests of Western Oregon's Central Cascades, USA Author: Dunn, Christopher J. Mixed-severity fire occurrence is increasingly recognized in Pseudotsuga forests of the Pacific Northwest, but questions remain about how tree mortality varies, and forest structure is altered, across the disturbance gradient observed in these fires. Therefore, we sampled live and dead biological legacies at 45 one ha plots, with four 0.10 ha nested plots, stratified across an unburned, low, moderate and high-severity fire gradient. We used severity estimates based on differenced Normalized Burn Ratio (dNBR), and captured a disturbance gradient, but plots in our low-severity class underestimated fire effects because of misclassification or delayed mortality. We estimated probability of mortality for shade-intolerant (Douglas-fir, incense-cedar, sugar pine) and shade-tolerant (western hemlock, western redcedar, true fir) trees from 5,079 sampled trees and snags. The probability of mortality was higher for shade-tolerant species across all fire-severity classes, and decreased with increasing DBH except for western hemlock. Only large, shade-intolerant trees survived high-severity fire. Post-fire snag fall and fragmentation were estimated from 2,746 sampled snags and logs. The probability of snag fall decreased with increasing DBH for all species, and was positively correlated with fire severity, except for Douglas-fir that had a higher probability following low-severity fire. Snag fragmentation was positively correlated with DBH and fire severity for all species. We also estimated the coefficient of variation within- and among-plots by fire severity class, as well as across all sampled conditions. Structural attributes varied more within- than among-plots, likely a result of increasing sub-hectare patchy mortality as fire intensity increased. Although vertical and horizontal structural diversity increased at sub-hectare scales, the coefficient of variation was highest for all structural attributes when compared across all fire severity classes. Therefore, the range of fire effects observed in mixed-severity fires may be functionally important in creating structural complexity across landscapes, which is an important attribute of old-growth forests in the Pacific Northwest. Understory vegetation response to mixed-severity fires has not been characterized for these forests even though the majority of vegetation diversity is found in these vegetation layers. Therefore, we sampled forest structure (1000 m² circular plots) and understory vegetation (100 m² plots) at 168 collocated plots stratified across unburned, low, moderate and high-severity conditions 10 years (Tiller Complex) and 22 years (Warner Fire) post-fire. We focused on shrub species, but sampled forbs, graminoids, ferns and moss as functional groups. Offsite colonization and fire stimulated soil seedbanks increased the total species richness from 23 to 46. The life-history strategies of residual and colonizing species resulted in three dominant species response-curves to the magnitude of disturbance: 1) 'disturbance-sensitive', when relative abundance was highest in unburned plots and continued to decline with increasing fire severity, 2) 'disturbance-stimulated', when relative abundance was highest following low or moderate-severity fire and 3) 'disturbance-amplified', when relative abundance increased with increasing fire severity. Residual and colonizing species assemblages promoted five or six distinct understory communities, dominantly driven by legacy tree basal area rather than the proportion of basal area killed. Understory communities were rarely associated with one disturbance severity class as fire refugia, variation in overstory and understory fire severity, and compensatory conditions offset fire effects. Early-seral habitats were the most different from unburned forests, but were not the only post-fire conditions important across these burned landscapes. Interactions among live and dead forest structures following low or moderate-severity fire, and the vegetation response to these conditions, are also unique to the post-fire landscape and likely important for various wildlife species. Therefore, if ecological forestry paradigms focus dominantly on creating old-growth structure or early-seral habitats, they might exclude important conditions that contribute to the landscape structural complexity created by mixed-severity fires. Additionally, tree regeneration response to mixed-severity fires has not been characterized for these forests even though they offer insight into one aspect of the resilience of these ecosystems to disturbance. Therefore, we sampled forest structure (1000 m² circular plots) and regeneration dynamics (100 m² plots) at 168 collocated plots stratified across unburned, low, moderate and high-severity conditions 10 years (Tiller Complex) and 22 years (Warner Fire) post-fire. The largest marginal increase in tree mortality (stems ha⁻¹) occurred between unburned and low-severity fires, given preferential mortality of small trees and shade-tolerant species, but basal area mortality had the largest marginal increase moving from moderate to high-severity. Pairwise comparisons of legacy tree basal area between low and moderate-severity weren’t as significant as other comparisons, but did capture a gradient of increasing fire effects. Quadratic mean diameter and canopy base height were positively correlated with fire severity as incrementally larger trees were killed and canopy ascension followed. Regeneration density increased regardless of severity, relative to unburned forests (median density of 1,384 trees ha⁻¹), but the highest median density (16,220 trees ha⁻¹) followed low-severity fire at the Tiller Complex and moderate-severity fire (14,472 trees ha⁻¹) at Warner Fire. Plot-level average species richness was highest following these same fire severity classes, supporting the Intermediate Disturbance Hypothesis. Statistically distinct regeneration communities occurred across the fire severity gradient at both fire sites. The relative abundance of shade-tolerant tree species decreased as fire severity increased, except for a divergent response following stand-initiation at the Warner Fire. While divergent successional pathways were evident within a couple decades following stand-initiation, low or moderate-severity fires also modified successional trajectories and may be the most functionally important disturbance magnitude because it has the greatest potential to increase compositional and structural diversity. Incorporating mixed-severity fire effects into landscape management of Pseudotsuga forests could increase structural complexity at stand and landscape-scales. Title: Mixed-Severity Fire Effects on Biological Legacies and Vegetation Response in Pseudotsuga Forests of Western Oregon's Central Cascades, USA Author: Dunn, Christopher J. Mixed-severity fire occurrence is increasingly recognized in Pseudotsuga forests of the Pacific Northwest, but questions remain about how tree mortality varies, and forest structure is altered, across the disturbance gradient observed in these fires. Therefore, we sampled live and dead biological legacies at 45 one ha plots, with four 0.10 ha nested plots, stratified across an unburned, low, moderate and high-severity fire gradient. We used severity estimates based on differenced Normalized Burn Ratio (dNBR), and captured a disturbance gradient, but plots in our low-severity class underestimated fire effects because of misclassification or delayed mortality. We estimated probability of mortality for shade-intolerant (Douglas-fir, incense-cedar, sugar pine) and shade-tolerant (western hemlock, western redcedar, true fir) trees from 5,079 sampled trees and snags. The probability of mortality was higher for shade-tolerant species across all fire-severity classes, and decreased with increasing DBH except for western hemlock. Only large, shade-intolerant trees survived high-severity fire. Post-fire snag fall and fragmentation were estimated from 2,746 sampled snags and logs. The probability of snag fall decreased with increasing DBH for all species, and was positively correlated with fire severity, except for Douglas-fir that had a higher probability following low-severity fire. Snag fragmentation was positively correlated with DBH and fire severity for all species. We also estimated the coefficient of variation within- and among-plots by fire severity class, as well as across all sampled conditions. Structural attributes varied more within- than among-plots, likely a result of increasing sub-hectare patchy mortality as fire intensity increased. Although vertical and horizontal structural diversity increased at sub-hectare scales, the coefficient of variation was highest for all structural attributes when compared across all fire severity classes. Therefore, the range of fire effects observed in mixed-severity fires may be functionally important in creating structural complexity across landscapes, which is an important attribute of old-growth forests in the Pacific Northwest. Understory vegetation response to mixed-severity fires has not been characterized for these forests even though the majority of vegetation diversity is found in these vegetation layers. Therefore, we sampled forest structure (1000 m² circular plots) and understory vegetation (100 m² plots) at 168 collocated plots stratified across unburned, low, moderate and high-severity conditions 10 years (Tiller Complex) and 22 years (Warner Fire) post-fire. We focused on shrub species, but sampled forbs, graminoids, ferns and moss as functional groups. Offsite colonization and fire stimulated soil seedbanks increased the total species richness from 23 to 46. The life-history strategies of residual and colonizing species resulted in three dominant species response-curves to the magnitude of disturbance: 1) 'disturbance-sensitive', when relative abundance was highest in unburned plots and continued to decline with increasing fire severity, 2) 'disturbance-stimulated', when relative abundance was highest following low or moderate-severity fire and 3) 'disturbance-amplified', when relative abundance increased with increasing fire severity. Residual and colonizing species assemblages promoted five or six distinct understory communities, dominantly driven by legacy tree basal area rather than the proportion of basal area killed. Understory communities were rarely associated with one disturbance severity class as fire refugia, variation in overstory and understory fire severity, and compensatory conditions offset fire effects. Early-seral habitats were the most different from unburned forests, but were not the only post-fire conditions important across these burned landscapes. Interactions among live and dead forest structures following low or moderate-severity fire, and the vegetation response to these conditions, are also unique to the post-fire landscape and likely important for various wildlife species. Therefore, if ecological forestry paradigms focus dominantly on creating old-growth structure or early-seral habitats, they might exclude important conditions that contribute to the landscape structural complexity created by mixed-severity fires. Additionally, tree regeneration response to mixed-severity fires has not been characterized for these forests even though they offer insight into one aspect of the resilience of these ecosystems to disturbance. Therefore, we sampled forest structure (1000 m² circular plots) and regeneration dynamics (100 m² plots) at 168 collocated plots stratified across unburned, low, moderate and high-severity conditions 10 years (Tiller Complex) and 22 years (Warner Fire) post-fire. The largest marginal increase in tree mortality (stems ha⁻¹) occurred between unburned and low-severity fires, given preferential mortality of small trees and shade-tolerant species, but basal area mortality had the largest marginal increase moving from moderate to high-severity. Pairwise comparisons of legacy tree basal area between low and moderate-severity weren’t as significant as other comparisons, but did capture a gradient of increasing fire effects. Quadratic mean diameter and canopy base height were positively correlated with fire severity as incrementally larger trees were killed and canopy ascension followed. Regeneration density increased regardless of severity, relative to unburned forests (median density of 1,384 trees ha⁻¹), but the highest median density (16,220 trees ha⁻¹) followed low-severity fire at the Tiller Complex and moderate-severity fire (14,472 trees ha⁻¹) at Warner Fire. Plot-level average species richness was highest following these same fire severity classes, supporting the Intermediate Disturbance Hypothesis. Statistically distinct regeneration communities occurred across the fire severity gradient at both fire sites. The relative abundance of shade-tolerant tree species decreased as fire severity increased, except for a divergent response following stand-initiation at the Warner Fire. While divergent successional pathways were evident within a couple decades following stand-initiation, low or moderate-severity fires also modified successional trajectories and may be the most functionally important disturbance magnitude because it has the greatest potential to increase compositional and structural diversity. Incorporating mixed-severity fire effects into landscape management of Pseudotsuga forests could increase structural complexity at stand and landscape-scales. Close

• 2355. [Article] The role of body size in the foraging strategies and management of avian herbivores : a comparison of dusky Canada geese (Branta canadensis occidentalis) and cackling geese (B. hutchinsii minima) wintering in the Willamette Valley of Oregon

  Body size explains much of the interspecific variation in the physiology, behavior, and morphology of birds, such as metabolic rate, diet selection, intake rate, gut size, and bill size. Based on mass-specific ...

  Citation × Citation Citation Abstract Copy Title: The role of body size in the foraging strategies and management of avian herbivores : a comparison of dusky Canada geese (Branta canadensis occidentalis) and cackling geese (B. hutchinsii minima) wintering in the Willamette Valley of Oregon Author: Mini, Anne E. Body size explains much of the interspecific variation in the physiology, behavior, and morphology of birds, such as metabolic rate, diet selection, intake rate, gut size, and bill size. Based on mass-specific metabolic requirements and relative energetic costs of activities, being a certain body size has both advantages and disadvantages. In particular, avian herbivores such as geese possess a relatively simple digestive system, consume foods with low digestibility and poor nutrient content, and have increased energetic demands compared to other bird taxa; therefore, any effects of body size on foraging strategies should be readily apparent in this foraging guild. The influence of body size on the behavior and management of Canada Geese (Branta canadensis) and Cackling Geese (B. hutchinsii) as avian herbivores has not been well studied. My dissertation explores the role of body size in comparative foraging behavior, habitat selection, and winter conservation planning for two congeneric geese, the Dusky Canada Goose (B. c. occidentalis; hereafter Duskys) and the Cackling Goose (B. h. minima; hereafter Cacklers). These two taxa share the same over-winter foraging environment (grass seed fields) in the same restricted geographic area (the Willamette Valley) during winter. Duskys and Cacklers differ by more than a factor of two in body size and have different relative bill sizes and social organization. Because of smaller body size, Cacklers have greater relative energy demands and less fasting endurance compared to Duskys; however, Cacklers have comparatively low energetic costs for flight and transport. Duskys, however, have higher total energy requirements than Cacklers. Additionally, Cacklers form large, high-density flocks and have a total over-wintering population size in the study area of about 200,000. Duskys occur in relatively small family groups and have a total over-wintering population size of about 13,000. My study demonstrated that interspecific differences in body size between Cacklers and Duskys was associated with differences in foraging behavior, movements, and habitat selection. Cacklers foraged a greater percentage of time (30%) in all habitats and across the entire winter compared to Duskys. Cacklers had higher peck rates (up to 100 pecks min⁻¹ greater) than Duskys in all foraging habitats expect pasture. The pecking rate of Cacklers was greatest in fields of young grass (200 pecks min⁻¹), which may indicate that Cacklers had relatively high intake rates in this foraging habitat. Based on differences in foraging behavior among habitats, Cacklers may have the foraging strategy of energy intake maximizers, whereas the foraging strategy of Duskys is more towards time-energy expenditure minimizers, at least for part of the winter. Cacklers moved across the landscape very differently from Duskys, exhibiting less site fidelity and greater commuting distances to foraging areas. Cacklers showed a preference for young grass during all periods of the winter, reaffirming that Cacklers are specialized grazers on short green forage, whereas Duskys preferred young grass and pasture. Fields of young grass were the preferred foraging habitat of Cacklers, had less standing crop biomass, and may have enabled higher foraging efficiencies, which may have led to higher intake rates. The ability of the landscape to support wintering geese changed across the winter because total available plant biomass fluctuated with the rate of grass regrowth. The estimated carrying capacity of the landscape for geese decline by almost one-half during mid-winter (mid-December to mid-February) compared to early winter or late winter periods. Although Cacklers have lower individual energy requirements compared to Duskys, due to a much larger target population size, Cacklers required 89% more foraging habitat than Duskys. Forage requirements encountered a bottleneck during mid-winter, when grass regrowth rates were low and day length was short. Commensurate with this pattern of forage availability, goose body condition declined during the mid-winter period. To support Pacific Flyway target populations for geese, approximately 18,000 ha of total grazing habitat in young and mature grass is needed in the Willamette Valley to support a total over-wintering population composed of 340,000 geese belonging to four subspecies. The role of body size in influencing the foraging behavior and decisions of over-wintering geese has important implications for conservation planning of goose populations. Small-bodied Cacklers are selective in field choice, yet more likely to redistribute across the landscape. Disturbances (e.g., hunting, hazing, or predation) will have a disproportionate effect on the movements of smaller-bodied geese compared to larger geese. These characteristics of Cacklers will make conservation planning to retain geese on public land more difficult. Coordinated management with private landowners and farming practices that maximize preferred goose foraging habitat on public lands may attract geese to utilize protected areas and minimize conflicts with agriculture in the Willamette Valley. Availability of resources during critical periods in winter is an important factor affecting the distribution of geese, but may affect small and large bodied geese differently. Management could be targeted during these critical time periods. By considering the role of body size in the context of life history characteristics, foraging behavior and habitat selection, appropriate management strategies can be developed and implemented to reduce the effects of agricultural depredation by geese, while promoting the future conservation of wintering geese in the Willamette Valley. Title: The role of body size in the foraging strategies and management of avian herbivores : a comparison of dusky Canada geese (Branta canadensis occidentalis) and cackling geese (B. hutchinsii minima) wintering in the Willamette Valley of Oregon Author: Mini, Anne E. Body size explains much of the interspecific variation in the physiology, behavior, and morphology of birds, such as metabolic rate, diet selection, intake rate, gut size, and bill size. Based on mass-specific metabolic requirements and relative energetic costs of activities, being a certain body size has both advantages and disadvantages. In particular, avian herbivores such as geese possess a relatively simple digestive system, consume foods with low digestibility and poor nutrient content, and have increased energetic demands compared to other bird taxa; therefore, any effects of body size on foraging strategies should be readily apparent in this foraging guild. The influence of body size on the behavior and management of Canada Geese (Branta canadensis) and Cackling Geese (B. hutchinsii) as avian herbivores has not been well studied. My dissertation explores the role of body size in comparative foraging behavior, habitat selection, and winter conservation planning for two congeneric geese, the Dusky Canada Goose (B. c. occidentalis; hereafter Duskys) and the Cackling Goose (B. h. minima; hereafter Cacklers). These two taxa share the same over-winter foraging environment (grass seed fields) in the same restricted geographic area (the Willamette Valley) during winter. Duskys and Cacklers differ by more than a factor of two in body size and have different relative bill sizes and social organization. Because of smaller body size, Cacklers have greater relative energy demands and less fasting endurance compared to Duskys; however, Cacklers have comparatively low energetic costs for flight and transport. Duskys, however, have higher total energy requirements than Cacklers. Additionally, Cacklers form large, high-density flocks and have a total over-wintering population size in the study area of about 200,000. Duskys occur in relatively small family groups and have a total over-wintering population size of about 13,000. My study demonstrated that interspecific differences in body size between Cacklers and Duskys was associated with differences in foraging behavior, movements, and habitat selection. Cacklers foraged a greater percentage of time (30%) in all habitats and across the entire winter compared to Duskys. Cacklers had higher peck rates (up to 100 pecks min⁻¹ greater) than Duskys in all foraging habitats expect pasture. The pecking rate of Cacklers was greatest in fields of young grass (200 pecks min⁻¹), which may indicate that Cacklers had relatively high intake rates in this foraging habitat. Based on differences in foraging behavior among habitats, Cacklers may have the foraging strategy of energy intake maximizers, whereas the foraging strategy of Duskys is more towards time-energy expenditure minimizers, at least for part of the winter. Cacklers moved across the landscape very differently from Duskys, exhibiting less site fidelity and greater commuting distances to foraging areas. Cacklers showed a preference for young grass during all periods of the winter, reaffirming that Cacklers are specialized grazers on short green forage, whereas Duskys preferred young grass and pasture. Fields of young grass were the preferred foraging habitat of Cacklers, had less standing crop biomass, and may have enabled higher foraging efficiencies, which may have led to higher intake rates. The ability of the landscape to support wintering geese changed across the winter because total available plant biomass fluctuated with the rate of grass regrowth. The estimated carrying capacity of the landscape for geese decline by almost one-half during mid-winter (mid-December to mid-February) compared to early winter or late winter periods. Although Cacklers have lower individual energy requirements compared to Duskys, due to a much larger target population size, Cacklers required 89% more foraging habitat than Duskys. Forage requirements encountered a bottleneck during mid-winter, when grass regrowth rates were low and day length was short. Commensurate with this pattern of forage availability, goose body condition declined during the mid-winter period. To support Pacific Flyway target populations for geese, approximately 18,000 ha of total grazing habitat in young and mature grass is needed in the Willamette Valley to support a total over-wintering population composed of 340,000 geese belonging to four subspecies. The role of body size in influencing the foraging behavior and decisions of over-wintering geese has important implications for conservation planning of goose populations. Small-bodied Cacklers are selective in field choice, yet more likely to redistribute across the landscape. Disturbances (e.g., hunting, hazing, or predation) will have a disproportionate effect on the movements of smaller-bodied geese compared to larger geese. These characteristics of Cacklers will make conservation planning to retain geese on public land more difficult. Coordinated management with private landowners and farming practices that maximize preferred goose foraging habitat on public lands may attract geese to utilize protected areas and minimize conflicts with agriculture in the Willamette Valley. Availability of resources during critical periods in winter is an important factor affecting the distribution of geese, but may affect small and large bodied geese differently. Management could be targeted during these critical time periods. By considering the role of body size in the context of life history characteristics, foraging behavior and habitat selection, appropriate management strategies can be developed and implemented to reduce the effects of agricultural depredation by geese, while promoting the future conservation of wintering geese in the Willamette Valley. Close

• 2356. [Article] Numerical Simulation, Laboratory and Field Experiments, Analysis and Design of Wave Energy Converter and Mooring System

  This dissertation studies the coupled fluid-structure interaction (FSI) of a wave energy converter (WEC) and evaluates the design of a WEC mooring system. The research is conducted in support of conceptual ...

  Citation × Citation Citation Abstract Copy Title: Numerical Simulation, Laboratory and Field Experiments, Analysis and Design of Wave Energy Converter and Mooring System Author: Lou, Junhui This dissertation studies the coupled fluid-structure interaction (FSI) of a wave energy converter (WEC) and evaluates the design of a WEC mooring system. The research is conducted in support of conceptual development, field test and performance evaluation of WECs as part of the mission of the Northwest National Marine Renewable Energy Center at Oregon State University. The coupled FSI study focuses on the evaluation of predictive capabilities and computational performance of commercial computational fluid dynamics (CFD) and potential flow codes using laboratory model test results. The evaluations of a WEC mooring system focus on analysis of field test data and evaluations of the anchor movability, fatigue design and extreme load of the Ocean Sentinel (OS) test platform mooring system deployed off the Oregon coast. Numerical data using a commercial mooring system simulation code are conducted to supplement time history data for the calculations of anchor pulling force, fatigue damage and extreme load. Specifically, this dissertation can be divided into three parts. In the first part the performances of a finite element explicit Navier-Stokes (NS) solver (LS-DYNA ALE), a finite element implicit NS solver (LS-DYNA ICFD), and a nonlinear potential flow solver (AQWA) in predicting highly nonlinear hydrodynamic responses of a floating point absorber (FPA) under large-amplitude waves are studied. The two NS solvers calculate the coupled FSI including fully nonlinear inviscid and viscous forces. The nonlinear potential flow solver calculates individual inviscid wave force components (a Froud-Krylov force, a radiation force, a diffraction force and a hydrostatic force) and empirical (Morison equation) viscous force. Comparing numerical results to laboratory experimental measurements, the two NS solvers and the nonlinear potential flow solver are found to be capable of providing accurate predictions of the nonlinear motion responses of the FPA. FSI coupling algorithms and computational costs of these three solvers are evaluated. Based on the results of the nonlinear potential flow solver at different wave periods, the individual wave force components and the viscous force are studied quantitatively. The nonlinearity of the restoring force and the Froude-Krylov force are found to be important for the FPA responses in all (heave, surge and pitch) directions; the nonlinearity of the viscous force is found to be important in only the heave and pitch directions. The second part first presents a catenary spread mooring system design of a mobile ocean test berth (MOTB), the Ocean Sentinel (OS) instrumentation buoy, which is developed by the Northwest National Marine Renewable Energy Center (NNMREC) to facilitate ocean test of wave energy converters (WECs). Then the OS mooring design, which is similar to a conventional WEC point absorber mooring system, is evaluated through both field test analysis and quasi-static analysis: the field test analysis is based on the extensive data of the OS positions, mooring tensions on the OS and environmental conditions of waves, wind and current, collected during the 2013 field test of the OS mooring system; the quasi-static analysis is based on the analytical catenary equations of mooring chains. Both global characteristics and survivability characteristics of the mooring system are evaluated: the global characteristics include the influence of the OS excursion to mooring tension, positional distribution of the OS, directional control of the OS and environmental contributions of waves, current and wind to mooring tensions; the survivability characteristics include the anchor movability and strength capacities of mooring. Because anchor movement occurred near the end of the field test, a systematic procedure of designing a mooring system with adequate anchor holding capacity is developed and applied to design a new OS mooring system. In the third part, first, the accuracies of a fully coupled method based numerical model in predicting the mooring tensions of the OS mooring system and the OS positions are validated by comparing the numerical results to the field data collected during the 2013 OS field test. Then, the anchor movability, fatigue damage and extreme mooring tension of the OS mooring system are investigated using the mooring tensions predicted by the numerical model. The results of the above studies are summarized as follows: (1) The numerical model provides accurate predictions of the mooring tensions and OS positions under harsh environmental conditions; (2) When the OS drifted significantly near the end of the field test, the bow, port and starboard anchors were likely not dragged, dragged significantly and dragged slightly, respectively; (3) The fatigue damages of mooring lines are predicted for environmental conditions from low to high sea states; and (4) The strengths of mooring lines in the original mooring design are adequate compared to the predicted extreme mooring tensions. Title: Numerical Simulation, Laboratory and Field Experiments, Analysis and Design of Wave Energy Converter and Mooring System Author: Lou, Junhui This dissertation studies the coupled fluid-structure interaction (FSI) of a wave energy converter (WEC) and evaluates the design of a WEC mooring system. The research is conducted in support of conceptual development, field test and performance evaluation of WECs as part of the mission of the Northwest National Marine Renewable Energy Center at Oregon State University. The coupled FSI study focuses on the evaluation of predictive capabilities and computational performance of commercial computational fluid dynamics (CFD) and potential flow codes using laboratory model test results. The evaluations of a WEC mooring system focus on analysis of field test data and evaluations of the anchor movability, fatigue design and extreme load of the Ocean Sentinel (OS) test platform mooring system deployed off the Oregon coast. Numerical data using a commercial mooring system simulation code are conducted to supplement time history data for the calculations of anchor pulling force, fatigue damage and extreme load. Specifically, this dissertation can be divided into three parts. In the first part the performances of a finite element explicit Navier-Stokes (NS) solver (LS-DYNA ALE), a finite element implicit NS solver (LS-DYNA ICFD), and a nonlinear potential flow solver (AQWA) in predicting highly nonlinear hydrodynamic responses of a floating point absorber (FPA) under large-amplitude waves are studied. The two NS solvers calculate the coupled FSI including fully nonlinear inviscid and viscous forces. The nonlinear potential flow solver calculates individual inviscid wave force components (a Froud-Krylov force, a radiation force, a diffraction force and a hydrostatic force) and empirical (Morison equation) viscous force. Comparing numerical results to laboratory experimental measurements, the two NS solvers and the nonlinear potential flow solver are found to be capable of providing accurate predictions of the nonlinear motion responses of the FPA. FSI coupling algorithms and computational costs of these three solvers are evaluated. Based on the results of the nonlinear potential flow solver at different wave periods, the individual wave force components and the viscous force are studied quantitatively. The nonlinearity of the restoring force and the Froude-Krylov force are found to be important for the FPA responses in all (heave, surge and pitch) directions; the nonlinearity of the viscous force is found to be important in only the heave and pitch directions. The second part first presents a catenary spread mooring system design of a mobile ocean test berth (MOTB), the Ocean Sentinel (OS) instrumentation buoy, which is developed by the Northwest National Marine Renewable Energy Center (NNMREC) to facilitate ocean test of wave energy converters (WECs). Then the OS mooring design, which is similar to a conventional WEC point absorber mooring system, is evaluated through both field test analysis and quasi-static analysis: the field test analysis is based on the extensive data of the OS positions, mooring tensions on the OS and environmental conditions of waves, wind and current, collected during the 2013 field test of the OS mooring system; the quasi-static analysis is based on the analytical catenary equations of mooring chains. Both global characteristics and survivability characteristics of the mooring system are evaluated: the global characteristics include the influence of the OS excursion to mooring tension, positional distribution of the OS, directional control of the OS and environmental contributions of waves, current and wind to mooring tensions; the survivability characteristics include the anchor movability and strength capacities of mooring. Because anchor movement occurred near the end of the field test, a systematic procedure of designing a mooring system with adequate anchor holding capacity is developed and applied to design a new OS mooring system. In the third part, first, the accuracies of a fully coupled method based numerical model in predicting the mooring tensions of the OS mooring system and the OS positions are validated by comparing the numerical results to the field data collected during the 2013 OS field test. Then, the anchor movability, fatigue damage and extreme mooring tension of the OS mooring system are investigated using the mooring tensions predicted by the numerical model. The results of the above studies are summarized as follows: (1) The numerical model provides accurate predictions of the mooring tensions and OS positions under harsh environmental conditions; (2) When the OS drifted significantly near the end of the field test, the bow, port and starboard anchors were likely not dragged, dragged significantly and dragged slightly, respectively; (3) The fatigue damages of mooring lines are predicted for environmental conditions from low to high sea states; and (4) The strengths of mooring lines in the original mooring design are adequate compared to the predicted extreme mooring tensions. Close

• 2357. [Article] Distribution, Abundance, and Settlement of Slope-spawning Flatfish during Early Life Stages in the Eastern Bering Sea

  Changes in environmental conditions in marine ecosystems could directly or indirectly influence distribution, abundance, settlement, and size at settlement of flatfish. Understanding species-specific and ...

  Citation × Citation Citation Abstract Copy Title: Distribution, Abundance, and Settlement of Slope-spawning Flatfish during Early Life Stages in the Eastern Bering Sea Author: Sohn, Dongwha Changes in environmental conditions in marine ecosystems could directly or indirectly influence distribution, abundance, settlement, and size at settlement of flatfish. Understanding species-specific and age-specific responses to environmental variability is important for managing commercially important flatfish stocks. Slope-spawning flatfish whose offspring rely on extensive drift from the slope (spawning) to the shelf (settlement) and which require specific habitat for settlement could be especially vulnerable to environmental variability. Arrowtooth flounder (ATF; Atheresthes stomias), Greenland halibut (GH; Reinhardtius hippoglossoides), and Pacific halibut (PH; Hippoglossus stenolepis) are commercially and ecologically important slope-spawning flatfish species in the eastern Bering Sea (EBS), which has experienced fluctuating warm and cold periods since 2000. Although the three species share many attributes, their population trajectories have fluctuated differently. This difference could result from contrasting responses to environmental variability during early life history. To understand how physical variability of the Bering Sea can differentially affect flatfish ecology from pre-settlement to post-settlement phases, I used a combination of field data, biophysical modeling, and statistical modeling to characterize early life stage attributes (chapter 2), settlement success (chapter 3), and size, abundance, and distribution at settlement (age-0) and age-1 (chapter 4). Based on historical ichthyoplankton survey data for GH and PH, I found that there were species-specific differences in the spatial distribution (vertically and horizontally) and juvenile nursery areas between the two species during early life stages in the EBS. Specifically, I found that PH larvae abruptly move to shallower water as they grow, and cross onto the shelf earlier than GH. This ontogenetic movement has the benefit of allowing PH larvae to take advantage of on-shelf transport to reach their settlement locations. However, an early transition from the slope to the shelf may not equally benefit GH, whose settlement locations are further from the spawning ground. Using a bio-physical modeling approach parameterized on the field data summarized in chapter 2, I found that species-specific variability of early life attributes causes interannual and species-specific variability of GH and PH settlement success in the EBS. GH settlement increased with increasing along-shelf (northwestward) flow whereas PH settlement decreased. GH that spawned in November and December were highly successful at settling while PH settlement was most successful when they spawned in January and February. Furthermore, GH settlement is affected by temperature dependence of pelagic larval duration, but not PH, indicating a strong resilience of PH to temperature induced variations in development and dispersal duration. Using otolith microstructure analysis, I found that variations in size at settlement for ATF are significantly correlated with latitude of sampling location. For GH, their size at settlement is associated with bottom water temperature and sea ice extent. Especially, sea ice coverage has a strong negative correlation with on-shelf winds, which drive along-shelf Ekman transport to southeast impacting dispersal pathways and duration. Size at settlement for ATF increased with increasing latitude of sampling location, which could be impacted by currents. For GH, size at settlement decreased with decreasing bottom water temperature and increasing sea ice extent. Also, my results showed that settlement habitat increases for GH in cold years whereas that of ATF increases in warm years. The bottom temperature of age-0 habitat for both ATF and GH affected on their age-1 abundance; GH age-1 abundance increased with decreasing bottom temperature of age-0 habitat, but no clear directionality was found for ATF. The findings from this study have implications for understanding settlement success and recruitment of slope-spawning flatfish in the EBS. In most cold years when along-shelf flow is generally strong, the level of larval supply of GH to their settlement areas is higher than in warm years. Size at settlement for GH decreased in cold years. The larger amount of suitable habitat for settlement and post-settlement stages could result in lower competition and less predation in comparison to warm years. In support of this hypothesis, I found greater age-1 abundance in cold years, indicating size at settlement in GH may not be critical compared to suitability of habitat features and larval supply to settlement grounds. On the other hand, in cold years with strong along-shelf transport to northwest, PH (or ATF), which settle in the southern part of the EBS, have lower numbers of successful settlers. Size at settlement for ATF increased in cold years, and I assumed that size at settlement for PH may have similar patterns. The amount of suitable habitat after settlement would be smaller, resulting in lower recruitment due to increased competition for limited resources. By studying how physical factors and their variability influence these three flatfish during early life stages, this study provides valuable insight into the response of flatfish stocks to past and future climate changes in the eastern Bering Sea – a system that is especially vulnerable to warming. Title: Distribution, Abundance, and Settlement of Slope-spawning Flatfish during Early Life Stages in the Eastern Bering Sea Author: Sohn, Dongwha Changes in environmental conditions in marine ecosystems could directly or indirectly influence distribution, abundance, settlement, and size at settlement of flatfish. Understanding species-specific and age-specific responses to environmental variability is important for managing commercially important flatfish stocks. Slope-spawning flatfish whose offspring rely on extensive drift from the slope (spawning) to the shelf (settlement) and which require specific habitat for settlement could be especially vulnerable to environmental variability. Arrowtooth flounder (ATF; Atheresthes stomias), Greenland halibut (GH; Reinhardtius hippoglossoides), and Pacific halibut (PH; Hippoglossus stenolepis) are commercially and ecologically important slope-spawning flatfish species in the eastern Bering Sea (EBS), which has experienced fluctuating warm and cold periods since 2000. Although the three species share many attributes, their population trajectories have fluctuated differently. This difference could result from contrasting responses to environmental variability during early life history. To understand how physical variability of the Bering Sea can differentially affect flatfish ecology from pre-settlement to post-settlement phases, I used a combination of field data, biophysical modeling, and statistical modeling to characterize early life stage attributes (chapter 2), settlement success (chapter 3), and size, abundance, and distribution at settlement (age-0) and age-1 (chapter 4). Based on historical ichthyoplankton survey data for GH and PH, I found that there were species-specific differences in the spatial distribution (vertically and horizontally) and juvenile nursery areas between the two species during early life stages in the EBS. Specifically, I found that PH larvae abruptly move to shallower water as they grow, and cross onto the shelf earlier than GH. This ontogenetic movement has the benefit of allowing PH larvae to take advantage of on-shelf transport to reach their settlement locations. However, an early transition from the slope to the shelf may not equally benefit GH, whose settlement locations are further from the spawning ground. Using a bio-physical modeling approach parameterized on the field data summarized in chapter 2, I found that species-specific variability of early life attributes causes interannual and species-specific variability of GH and PH settlement success in the EBS. GH settlement increased with increasing along-shelf (northwestward) flow whereas PH settlement decreased. GH that spawned in November and December were highly successful at settling while PH settlement was most successful when they spawned in January and February. Furthermore, GH settlement is affected by temperature dependence of pelagic larval duration, but not PH, indicating a strong resilience of PH to temperature induced variations in development and dispersal duration. Using otolith microstructure analysis, I found that variations in size at settlement for ATF are significantly correlated with latitude of sampling location. For GH, their size at settlement is associated with bottom water temperature and sea ice extent. Especially, sea ice coverage has a strong negative correlation with on-shelf winds, which drive along-shelf Ekman transport to southeast impacting dispersal pathways and duration. Size at settlement for ATF increased with increasing latitude of sampling location, which could be impacted by currents. For GH, size at settlement decreased with decreasing bottom water temperature and increasing sea ice extent. Also, my results showed that settlement habitat increases for GH in cold years whereas that of ATF increases in warm years. The bottom temperature of age-0 habitat for both ATF and GH affected on their age-1 abundance; GH age-1 abundance increased with decreasing bottom temperature of age-0 habitat, but no clear directionality was found for ATF. The findings from this study have implications for understanding settlement success and recruitment of slope-spawning flatfish in the EBS. In most cold years when along-shelf flow is generally strong, the level of larval supply of GH to their settlement areas is higher than in warm years. Size at settlement for GH decreased in cold years. The larger amount of suitable habitat for settlement and post-settlement stages could result in lower competition and less predation in comparison to warm years. In support of this hypothesis, I found greater age-1 abundance in cold years, indicating size at settlement in GH may not be critical compared to suitability of habitat features and larval supply to settlement grounds. On the other hand, in cold years with strong along-shelf transport to northwest, PH (or ATF), which settle in the southern part of the EBS, have lower numbers of successful settlers. Size at settlement for ATF increased in cold years, and I assumed that size at settlement for PH may have similar patterns. The amount of suitable habitat after settlement would be smaller, resulting in lower recruitment due to increased competition for limited resources. By studying how physical factors and their variability influence these three flatfish during early life stages, this study provides valuable insight into the response of flatfish stocks to past and future climate changes in the eastern Bering Sea – a system that is especially vulnerable to warming. Close

• 2358. [Article] Managing Marine Resources in Oregon’s Territorial Sea and Ocean Stewardship Area: The importance of environmental information in planning and decision making

  Oregon has a strong framework for ocean planning rooted in the adoption of Oregon’s Ocean Resources Goal 19 in 1976. Goal 19 establishes that it is the State of Oregon’s policy to conserve marine resources ...

  Citation × Citation Citation Abstract Copy Title: Managing Marine Resources in Oregon’s Territorial Sea and Ocean Stewardship Area: The importance of environmental information in planning and decision making Author: Snow, Patty Oregon has a strong framework for ocean planning rooted in the adoption of Oregon’s Ocean Resources Goal 19 in 1976. Goal 19 establishes that it is the State of Oregon’s policy to conserve marine resources and ecological functions for the purpose of providing long-term ecological, economic, and social value and benefits to future generations. To this end, all actions by local, state and federal agencies that are likely to affect the ocean resources and uses of Oregon’s territorial sea are to be developed and conducted to conserve marine resources and ecological functions. Higher priority is given to the protection of renewable marine resources (living marine organisms) than to the development of non-renewable ocean resources. This ocean planning framework was further codified by the Oregon Ocean Resource Management Act (ORS 196.405 to 196.485) passed in 1991 which created the Oregon ocean governance structure. The Oregon Territorial Sea Plan (TSP) which contains specific polices for state ocean management was originally adopted in 1994. The TSP was modified in 2009 to address policies for managing marine renewable energy development. A process is underway to use spatial planning techniques to identify areas appropriate for marine renewable energy development; adoption of these amendments to the TSP is anticipated in January 2013. Goal 19 also establishes the policy framework for the Ocean Stewardship Area which is defined to include the state’s territorial sea (out to three nautical miles), the continental margin seaward to the toe of the continental slope, and adjacent ocean areas. The Ocean Stewardship area is further addressed in the TSP. Goal 19, the Oregon Ocean Resources Management Act, and the TSP all state that prior to taking an action that is likely to affect ocean resources or uses of Oregon’s territorial sea, state and federal agencies are required to assess the reasonably foreseeable adverse effects of the action. The effects assessment is also to address reasonably foreseeable adverse effects on Oregon’s estuaries and shorelands. The information and protection requirements outlined below apply both on a planning scale (i.e., Territorial sea Plan) and on a permit-by-permit basis (i.e., OPT permit). Information is needed for the territorial sea, the ocean stewardship area and the outer continental shelf. Oregon’s Ocean Resources Goal 19, the Oregon Resources Management Act, and the TSP all require the protection of certain resources: a. Renewable marine resources; b. Biological diversity of marine life and the functional integrity of the marine ecosystem; c. Important marine habitat including areas: 1. Important to the biological viability of commercially or recreationally caught species or that support important food or prey species for commercially or recreationally caught species; or 2. needed to assure the survival of threatened or endangered species; 3. ecologically significant to maintain ecosystem structure, biological productivity, and biological diversity; 4. essential to the life-history or behavior of marine organisms; or 5. especially vulnerable because of size, composition, or location in relation to chemical or other pollutants, noise, physical disturbance, alteration, or harvest; or 6. unique or of limited range within the state: and d. Areas important to fisheries, which are: 1. areas of high catch; or 2. areas where highly valued fish are caught even if in low abundance or by few fishers; or 3. areas that are important on a seasonal basis; or 4. areas important to commercial or recreational fishing activities, including those of individual ports or particular fleets; or 5. habitat areas that support food or prey species important to commercially and recreationally caught fish and shellfish species. 6. Agencies are also to protect and encourage beneficial uses of ocean resources such as navigation, food production, recreation, aesthetic enjoyment, and uses of the seafloor provided that the activities do not adversely affect the resources protected in 1-4 above. To support the TSP spatial planning process and meet Goal 19 planning information requirements, the State of Oregon has developed a spatial decision support tool called MarineMap. It displays Oregon’s Ocean GIS database online and currently encompasses over 200 data layers including: a. Commercial and recreational fisheries data collected through local advisory committees for areas important to fisheries (Winter 2011); b. Ecological data collected by the Oregon Department of Fish and Wildlife (Summer 2011); c. Seafloor bathymetric and image data (Summer 2011); d. Recreational ocean use determined by on-line surveys (Fall 2010); e. Visual assessment inventory information (Summer 2012); f. Other spatial data on human uses, managed resources, physical conditions, and shoreland facilities (Fall 2010). This information has been used as part of the geospatial analysis to develop areas to be protected by Goal 19 in the current TSP mapping process. Currently, the draft recommendation is for six areas or zones: a. Renewable Energy Exclusion Area (REEA); b. Proprietary Use and Management Area (PUMA); c. Resources and Uses Conservation Area (RUCA); d. Resources and Uses Management Area (RUMA); e. Renewable Energy Facility Suitability Study Area (REFSSA); f. Renewable Energy Permit Area (REPA). Standards are the most stringent in the conservation area and least stringent in the study area. In addition, the draft recommendations include two overlay zones and screening standards that would apply across the territorial sea: 1. Visual Resource Area Overlay; 2. Marine Recreation Area Overlay. Information will be needed for permit applications in each of these zones but will be more extensive in conservation areas to ensure that important resources are protected. Permits for marine renewable energy projects in the future will be subject to different screening standards depending on what zone or area they are proposed in. While Oregon has created an innovative marine spatial planning decision support tool, the state continues to need additional information to ground truth assumptions, fill in information gaps, reduce uncertainties, and provide expert opinions. In addition, the state is working with other West Coast states to create a regional data framework that will facilitate regional decision-making and planning efforts. Title: Managing Marine Resources in Oregon’s Territorial Sea and Ocean Stewardship Area: The importance of environmental information in planning and decision making Author: Snow, Patty Oregon has a strong framework for ocean planning rooted in the adoption of Oregon’s Ocean Resources Goal 19 in 1976. Goal 19 establishes that it is the State of Oregon’s policy to conserve marine resources and ecological functions for the purpose of providing long-term ecological, economic, and social value and benefits to future generations. To this end, all actions by local, state and federal agencies that are likely to affect the ocean resources and uses of Oregon’s territorial sea are to be developed and conducted to conserve marine resources and ecological functions. Higher priority is given to the protection of renewable marine resources (living marine organisms) than to the development of non-renewable ocean resources. This ocean planning framework was further codified by the Oregon Ocean Resource Management Act (ORS 196.405 to 196.485) passed in 1991 which created the Oregon ocean governance structure. The Oregon Territorial Sea Plan (TSP) which contains specific polices for state ocean management was originally adopted in 1994. The TSP was modified in 2009 to address policies for managing marine renewable energy development. A process is underway to use spatial planning techniques to identify areas appropriate for marine renewable energy development; adoption of these amendments to the TSP is anticipated in January 2013. Goal 19 also establishes the policy framework for the Ocean Stewardship Area which is defined to include the state’s territorial sea (out to three nautical miles), the continental margin seaward to the toe of the continental slope, and adjacent ocean areas. The Ocean Stewardship area is further addressed in the TSP. Goal 19, the Oregon Ocean Resources Management Act, and the TSP all state that prior to taking an action that is likely to affect ocean resources or uses of Oregon’s territorial sea, state and federal agencies are required to assess the reasonably foreseeable adverse effects of the action. The effects assessment is also to address reasonably foreseeable adverse effects on Oregon’s estuaries and shorelands. The information and protection requirements outlined below apply both on a planning scale (i.e., Territorial sea Plan) and on a permit-by-permit basis (i.e., OPT permit). Information is needed for the territorial sea, the ocean stewardship area and the outer continental shelf. Oregon’s Ocean Resources Goal 19, the Oregon Resources Management Act, and the TSP all require the protection of certain resources: a. Renewable marine resources; b. Biological diversity of marine life and the functional integrity of the marine ecosystem; c. Important marine habitat including areas: 1. Important to the biological viability of commercially or recreationally caught species or that support important food or prey species for commercially or recreationally caught species; or 2. needed to assure the survival of threatened or endangered species; 3. ecologically significant to maintain ecosystem structure, biological productivity, and biological diversity; 4. essential to the life-history or behavior of marine organisms; or 5. especially vulnerable because of size, composition, or location in relation to chemical or other pollutants, noise, physical disturbance, alteration, or harvest; or 6. unique or of limited range within the state: and d. Areas important to fisheries, which are: 1. areas of high catch; or 2. areas where highly valued fish are caught even if in low abundance or by few fishers; or 3. areas that are important on a seasonal basis; or 4. areas important to commercial or recreational fishing activities, including those of individual ports or particular fleets; or 5. habitat areas that support food or prey species important to commercially and recreationally caught fish and shellfish species. 6. Agencies are also to protect and encourage beneficial uses of ocean resources such as navigation, food production, recreation, aesthetic enjoyment, and uses of the seafloor provided that the activities do not adversely affect the resources protected in 1-4 above. To support the TSP spatial planning process and meet Goal 19 planning information requirements, the State of Oregon has developed a spatial decision support tool called MarineMap. It displays Oregon’s Ocean GIS database online and currently encompasses over 200 data layers including: a. Commercial and recreational fisheries data collected through local advisory committees for areas important to fisheries (Winter 2011); b. Ecological data collected by the Oregon Department of Fish and Wildlife (Summer 2011); c. Seafloor bathymetric and image data (Summer 2011); d. Recreational ocean use determined by on-line surveys (Fall 2010); e. Visual assessment inventory information (Summer 2012); f. Other spatial data on human uses, managed resources, physical conditions, and shoreland facilities (Fall 2010). This information has been used as part of the geospatial analysis to develop areas to be protected by Goal 19 in the current TSP mapping process. Currently, the draft recommendation is for six areas or zones: a. Renewable Energy Exclusion Area (REEA); b. Proprietary Use and Management Area (PUMA); c. Resources and Uses Conservation Area (RUCA); d. Resources and Uses Management Area (RUMA); e. Renewable Energy Facility Suitability Study Area (REFSSA); f. Renewable Energy Permit Area (REPA). Standards are the most stringent in the conservation area and least stringent in the study area. In addition, the draft recommendations include two overlay zones and screening standards that would apply across the territorial sea: 1. Visual Resource Area Overlay; 2. Marine Recreation Area Overlay. Information will be needed for permit applications in each of these zones but will be more extensive in conservation areas to ensure that important resources are protected. Permits for marine renewable energy projects in the future will be subject to different screening standards depending on what zone or area they are proposed in. While Oregon has created an innovative marine spatial planning decision support tool, the state continues to need additional information to ground truth assumptions, fill in information gaps, reduce uncertainties, and provide expert opinions. In addition, the state is working with other West Coast states to create a regional data framework that will facilitate regional decision-making and planning efforts. Close

• 2359. [Article] Resource Selection, and Demographic Rates of Female Greater Sage-Grouse Following Large-Scale Wildfire

  Understanding the effects of habitat disturbance on a species' habitat selection patterns, and demographic rates, is essential to projecting the trajectories of populations affected by disturbance, as ...

  Citation × Citation Citation Abstract Copy Title: Resource Selection, and Demographic Rates of Female Greater Sage-Grouse Following Large-Scale Wildfire Author: Foster, Lee (Lee Jacob) Understanding the effects of habitat disturbance on a species' habitat selection patterns, and demographic rates, is essential to projecting the trajectories of populations affected by disturbance, as well as for determining the appropriate conservation actions needed to maintain those populations. Greater sage-grouse (Centrocercus urophasianus) is a species of conservation concern in western North America. The distribution of the species has been reduced by approximately half since European settlement, with concurrent and continuing population declines across its occupied range. The primary threats to the species are habitat alteration and loss, caused by multiple factors. In the western portion of its distribution, increasing wildfire activity is a primary cause of habitat loss and degradation. Single wildfires in this area may now reach extremely large sizes (>100,000 ha), and wildfires have been linked to local population declines. However, no published studies, to date, have examined the immediate effects of large-scale wildfire on sage-grouse habitat selection and demographic rates, using modern telemetry methods. I studied the habitat selection patterns, nest success, and survival of adult, and yearling female sage-grouse, captured within or near the Holloway fire, using state-of-the-art GPS-PTT telemetry methods. The Holloway fire burned ~187,000 ha of highly productive sage-grouse habitat in August, 2012. My study began during the first spring post-fire (March, 2013), and continued through February, 2015. I monitored seasonal habitat use patterns, and site-fidelity of sage-grouse, and modeled third-order seasonal resource selection, using mixed effects resource selection functions, in relation to characteristics of the post-fire habitat mosaic, terrain, mesic habitat availability, and herbaceous vegetation regeneration. I described sage-grouse nesting habitat use, nesting effort, and modeled daily nest survival in relation to temporal patterns, patch scale vegetation, biological factors, and landscape-scale habitat composition. I modeled adult and yearling female sage-grouse survival in relation to temporal patterns, biological factors, and landscape-scale habitat composition. Female sage-grouse primarily exhibited a three range seasonal movement pattern, with differentiation between breeding-nesting-early brood-rearing habitat (mean use dates: 8 Mar - 12 Jun), late brood-rearing-summer habitat (13 Jun - 20 Oct), and winter habitat (21 Oct - 7 Mar). However there was variation in seasonal range behavior among individuals. Sage-grouse exhibited considerable fidelity to all seasonal ranges, for individuals which survived >1 yr, mean distance between seasonal range centroids of the same type were 1.80 km, 1.65 km, and 3.96 km, for breeding ranges, summer ranges, and winter ranges, respectively. Within seasonal ranges, sage-grouse exhibited third-order resource selection patterns similar to those observed for populations in undisturbed habitats. Sage-grouse, at the population level, selected for level terrain throughout the year. During the breeding season sage-grouse selected for areas with increased amounts of intact sagebrush land-cover within a 1-km² area around used locations, areas of increased NDVI values within a 6.25-km² area, an amount of mesic habitat within a 6.25-km² area roughly equal to that available on the landscape, and mid-level elevations. During summer, sage-grouse, at the population level, selected for an areas with an intermediate density of burned-intact habitat edge within a 1 km² area, areas of increased NDVI values within a 6.25-km² area, intermediate distances to mesic habitat, and high elevations. During winter, sage-grouse, at the population level, selected for increased amounts of intact sagebrush land-cover within a 0.089-km² area, areas with decreased variation in NDVI within a 0.089-km² area, an amount of mesic habitat within a 6.25-km² area roughly equal to that available on the landscape, and intermediate elevations. There was considerable variation in third-order resource selection patterns among individuals during all seasons. Sage-grouse nest success was consistently low during the study (2013: 19.3%, 2014: 30.1%), and nest initiation rates were average to high (2013: 1st nest initiation = 90.5%, 2nd nest initiation = 23.1%; 2014: 1st nest initiation = 100%, 2nd nest initiation = 57.1%). Daily nest survival rates were influenced by an interaction between year and nesting attempt, and by forb cover within 5 m of the nest. Nest survival over the incubation period was consistently low for 1st and 2nd nests during 2013, and for 1st nests during 2014 (range: 0.131 - 0.212), but increased to 0.744 for 2nd nests during 2014. Forb cover within 5 m of the nest had a positive effect on daily nest survival rates, with a 1% increase in forb cover increasing the probability of a nest surviving a given day by 1.02 times. We did not detect strong direct effects of habitat or biological characteristics on survival of adult and yearling female sage-grouse. Rather, survival varied by month with lowest survival occurring in April and August of each year, and highest survival occurring during the winter. While patterns of monthly survival were similar between years, there was a strong, negative additive effect on survival which extended from the beginning of the study (March, 2013), through the end of the first post fire growing season (July, 2013). Although monthly survival increased following the end of the 1st post-fire growing season, yearly survival over both the 1st and 2nd biological years post-fire was low (March 2013 - February 2014: 24.0%; March 2014 - February 2015: 37.9%). These results indicate that female greater-sage grouse do not respond to wildfire related habitat disturbance through emigration, and rather continue to attempt to exist and reproduce in habitats disturbed by wildfire during the immediate years following a fire. While, due to site-fidelity, sage-grouse are not able to leave wildfire affected seasonal ranges, within those seasonal ranges they still attempt to utilize habitat components which most closely match their life-history requirements. However, this behavior appears to have an acute fitness cost to individuals, with reduced nesting success and survival of individuals utilizing fire-affected habitats during the first two years post-fire. This reduction in demographic rates likely explains observed sage-grouse population declines following wildfire, and indicates that these population declines are not the result of sage-grouse emigration away from fire-affected leks, but rather a true decline in the number of individual sage-grouse on the landscape following large-scale wildfire. Title: Resource Selection, and Demographic Rates of Female Greater Sage-Grouse Following Large-Scale Wildfire Author: Foster, Lee (Lee Jacob) Understanding the effects of habitat disturbance on a species' habitat selection patterns, and demographic rates, is essential to projecting the trajectories of populations affected by disturbance, as well as for determining the appropriate conservation actions needed to maintain those populations. Greater sage-grouse (Centrocercus urophasianus) is a species of conservation concern in western North America. The distribution of the species has been reduced by approximately half since European settlement, with concurrent and continuing population declines across its occupied range. The primary threats to the species are habitat alteration and loss, caused by multiple factors. In the western portion of its distribution, increasing wildfire activity is a primary cause of habitat loss and degradation. Single wildfires in this area may now reach extremely large sizes (>100,000 ha), and wildfires have been linked to local population declines. However, no published studies, to date, have examined the immediate effects of large-scale wildfire on sage-grouse habitat selection and demographic rates, using modern telemetry methods. I studied the habitat selection patterns, nest success, and survival of adult, and yearling female sage-grouse, captured within or near the Holloway fire, using state-of-the-art GPS-PTT telemetry methods. The Holloway fire burned ~187,000 ha of highly productive sage-grouse habitat in August, 2012. My study began during the first spring post-fire (March, 2013), and continued through February, 2015. I monitored seasonal habitat use patterns, and site-fidelity of sage-grouse, and modeled third-order seasonal resource selection, using mixed effects resource selection functions, in relation to characteristics of the post-fire habitat mosaic, terrain, mesic habitat availability, and herbaceous vegetation regeneration. I described sage-grouse nesting habitat use, nesting effort, and modeled daily nest survival in relation to temporal patterns, patch scale vegetation, biological factors, and landscape-scale habitat composition. I modeled adult and yearling female sage-grouse survival in relation to temporal patterns, biological factors, and landscape-scale habitat composition. Female sage-grouse primarily exhibited a three range seasonal movement pattern, with differentiation between breeding-nesting-early brood-rearing habitat (mean use dates: 8 Mar - 12 Jun), late brood-rearing-summer habitat (13 Jun - 20 Oct), and winter habitat (21 Oct - 7 Mar). However there was variation in seasonal range behavior among individuals. Sage-grouse exhibited considerable fidelity to all seasonal ranges, for individuals which survived >1 yr, mean distance between seasonal range centroids of the same type were 1.80 km, 1.65 km, and 3.96 km, for breeding ranges, summer ranges, and winter ranges, respectively. Within seasonal ranges, sage-grouse exhibited third-order resource selection patterns similar to those observed for populations in undisturbed habitats. Sage-grouse, at the population level, selected for level terrain throughout the year. During the breeding season sage-grouse selected for areas with increased amounts of intact sagebrush land-cover within a 1-km² area around used locations, areas of increased NDVI values within a 6.25-km² area, an amount of mesic habitat within a 6.25-km² area roughly equal to that available on the landscape, and mid-level elevations. During summer, sage-grouse, at the population level, selected for an areas with an intermediate density of burned-intact habitat edge within a 1 km² area, areas of increased NDVI values within a 6.25-km² area, intermediate distances to mesic habitat, and high elevations. During winter, sage-grouse, at the population level, selected for increased amounts of intact sagebrush land-cover within a 0.089-km² area, areas with decreased variation in NDVI within a 0.089-km² area, an amount of mesic habitat within a 6.25-km² area roughly equal to that available on the landscape, and intermediate elevations. There was considerable variation in third-order resource selection patterns among individuals during all seasons. Sage-grouse nest success was consistently low during the study (2013: 19.3%, 2014: 30.1%), and nest initiation rates were average to high (2013: 1st nest initiation = 90.5%, 2nd nest initiation = 23.1%; 2014: 1st nest initiation = 100%, 2nd nest initiation = 57.1%). Daily nest survival rates were influenced by an interaction between year and nesting attempt, and by forb cover within 5 m of the nest. Nest survival over the incubation period was consistently low for 1st and 2nd nests during 2013, and for 1st nests during 2014 (range: 0.131 - 0.212), but increased to 0.744 for 2nd nests during 2014. Forb cover within 5 m of the nest had a positive effect on daily nest survival rates, with a 1% increase in forb cover increasing the probability of a nest surviving a given day by 1.02 times. We did not detect strong direct effects of habitat or biological characteristics on survival of adult and yearling female sage-grouse. Rather, survival varied by month with lowest survival occurring in April and August of each year, and highest survival occurring during the winter. While patterns of monthly survival were similar between years, there was a strong, negative additive effect on survival which extended from the beginning of the study (March, 2013), through the end of the first post fire growing season (July, 2013). Although monthly survival increased following the end of the 1st post-fire growing season, yearly survival over both the 1st and 2nd biological years post-fire was low (March 2013 - February 2014: 24.0%; March 2014 - February 2015: 37.9%). These results indicate that female greater-sage grouse do not respond to wildfire related habitat disturbance through emigration, and rather continue to attempt to exist and reproduce in habitats disturbed by wildfire during the immediate years following a fire. While, due to site-fidelity, sage-grouse are not able to leave wildfire affected seasonal ranges, within those seasonal ranges they still attempt to utilize habitat components which most closely match their life-history requirements. However, this behavior appears to have an acute fitness cost to individuals, with reduced nesting success and survival of individuals utilizing fire-affected habitats during the first two years post-fire. This reduction in demographic rates likely explains observed sage-grouse population declines following wildfire, and indicates that these population declines are not the result of sage-grouse emigration away from fire-affected leks, but rather a true decline in the number of individual sage-grouse on the landscape following large-scale wildfire. Close

• 2360. [Article] The oligocene and miocene geology of the Tillamook embayment Tillamook County, northwest Oregon

  Eleven sedimentary and volcanic rock units are mapped and described in the thesis area, and chronicle the dynamic geologic history of the Tillamook embayment from the Oligocene through the middle Mlocene. ...

  Citation × Citation Citation Abstract Copy Title: The oligocene and miocene geology of the Tillamook embayment Tillamook County, northwest Oregon Author: Parker, Michael J. (Michael John), 1958- Eleven sedimentary and volcanic rock units are mapped and described in the thesis area, and chronicle the dynamic geologic history of the Tillamook embayment from the Oligocene through the middle Mlocene. The oldest unit is the Zemorrian to early Saucesian Smuggler Cove formation, a bathyal tuffaceous mudstone with some thin- to thick-bedded tuff layers deposited on the middle to upper continental slope during a period of explosive silicic volcanism in the Western Cascade arc. Uppermost Smuggler Cove strata are coarser grained, grading upward to arkosic turbidite sandstone and mudstone and thick bloturbated silty sandstone deposited on the outer shelf during marine regression. This regression heralded the progradation of the overlying shallow-marine Bewley Creek formation (informal) depositional system. The Bewley Creek formation (informal) is proposed in this study for a sequence of pumiceous, volcaniclastic-rich lower Miocene feldspathic litharenites and lithic arkoses deposited during the Pillarlan-stage near the mouth of an ancestral Columbia River. The unit grades from bioturbated silty sandstone to fine-grained hummocky cross-stratified and coarser grained channelized sandstones deposited within, or peripheral to a wave-dominated delta or ebb tidal-delta channel complex. Progradatlon of the Bewley Creek formation may have been caused, in part, by increased volcaniclastic sedimentation attending a pulse of explosive volcanism in the adjacent Western Cascade arc. Reduced volcanic activity, possibly coupled with basin subsidence or eustatic sea level rise, resulted in deposition of mudstones of the Sutton Creek member (informal; proposed) of the Nye Mudstone. The Saucesian Sutton Creek member consists of bathyal, laminated, carbonaceous, and moderately tuffaceous mudstone deposited in an upper continental slope basin. The upper part of the unit contains common lithic to arkosic turbidite sandstone interbeds within nested channel-fill deposits. These strata represent a channelized shelf-slope break environment adjacent to the shallow-marine Angora Peak member of the Astoria Formation depositlonal system. Subsequent marine regression resulted in progradation of the Pillarian- to Newportian-stage arkosic-micaceous sandstone-rich Angora Peak member into the Tillamook embayment. Grainsize analysis, sandstone petrography, scanning electron microscopy, and heavy mineral analyses suggest these lower to middle Miocene mollusk-bearing, fine- to medium-grained sandstones were predominantly deposited near the mouth of an ancestral Columbia River. They accumulated on a high-energy Inner shelf within or down drift of a wave-dominated delta or ebb-tidal delta complex, evidenced by paleocurrent analyses, hummocky cross-stratification and trough cross-stratified submarine channel-fill sequences. The Angora Peak member disconformably overlies Zemorrian mudstones of the Smuggler Cove formation at Cape Kiwanda suggesting local uplift and erosion in that area, followed by Newportian stage transgression in the Tillamook embayment. Exotic cobbles and boulders of two mica granite and sedimentary quartzite at Cape Kiwanda were probably derived from the Idaho Batholith and Precambrian sandstone terrains in Montana, transported via an ancestral Columbia River and longshore current to the shelf possibly bound within tree root bundles. The Netarts Bay member (informal) of the Astoria Formation Is proposed In this study for a late Sauceslan package of fine-grained to pebbly amalgamated and interbedded turbidite, grainflow, and fluldized flow friable thick-bedded lithic arkoses. These massive sandstones contain large penecontemporaneously emplaced channel wall-blocks and naller slltstone rip-ups. These lower to middle Miocene strata were deposited in a submarine canyon head and channel complex offshore of the shallow-marine Angora Peak member depositlonal system. Netarts Bay strata cut Into the underlying Angora Peak shelf strata, and cut and Interfinger with bathyal slope mudstones of the Cannon Beach member of the Astoria Formation. The overlying lower Cannon Beach member Is composed of laminated bathyal mudstones with rare turbidite sandstone interbeds deposited in a coarse clastic-starved slope environment. Upper Cannon Beach member strata In the Tillamook area are characterized by micaceous arkosic and lithic arkosic turbidite sandstones that underlie and occur within nested channel-fill sequences. Bloturbated carbonaceous cross-bedded sandstone In the upper Cannon Beach member records shallowing of the Tillamook embayment to a channelized upper slope to shelf environment. The Tillamook embayment was uplifted and dissected prior to the arrival of six to ten Intracanyon subaerial and submarine lava flows of the Columbia River Basalt Group. These middle Miocene flows, delineatedon the basis of geochemical composition and magnetic polarity, Include (in stratigraphic order) the Grouse Creek (R2 low MgO-low T102), Winterwater (N2 low MgO-low Ti02), and Sentinel Bluffs (high MgO) units of the Grande Ronde Basalt, and the Ginkgo unit of the Frenchman Springs member of the Wanapum Basalt. Orientation of Grande Ponde Basalt foreset-bedded pillow palagonite complexes and lava delta sequences indicate that these Columbia River Basalt units flowed westward into the Tillainook embayment, possibly through a saddle in the ancestral Oregon Coast Range. Marine transgression and deposition of hummocky cross-stratified arkosic marine strata of the Sandstone of Whale Cove followed emplacement of the last Grande Ronde flows. This was succeeded by a regression, as Indicated by the overlying subaerial plagioclase-phyric Ginkgo Unit flow of the Frenchman Springs Basalt. Locally, Winterwater and Sentinel Bluffs unit basalt occur as brecciated peperitic sills and dikes. These were emplaced through the process of "auto-invasion" when dense lava injected downward Into semi-lithifled Tertiary strata under the influence of both a pressure head augmented by flashing steam, and steam blasting. The thesis area is crossed by a complex network of high-angle northwest- and northeast-tending normal and reverse faults, and both low and high-angle east-trending reverse and thrust faults. These faults may have developed through a north-south compressional tectonic regime, a dextral shear couple, or a combination of these two tectonic regimes. Many faults cut Columbia River Basalt units and are thus middle Miocene or younger in age. Tertiary strata including the Columbia River Basalts are also folded within a broad westward-plunging syncline which suggests a middle Miocene or younger compressional event. Source rock analyses indicate that the mudstones of the Cannon Beach member, Sutton Creek member, and Smuggler Cove formation contain type III kerogen capable of generating natural gas only. Although these rocks have thermally innature vitrinite reflectance values, they contain sufficiently high total organic carbon content to be considered potential lean source rocks. Arkosic sandstones of the Angora Peak and Netarts Bay members have fair to good reservoir rock characteristics, and may represent reservoirs offshore for matured hydrocarbons generated from deeply buried source rocks. Title: The oligocene and miocene geology of the Tillamook embayment Tillamook County, northwest Oregon Author: Parker, Michael J. (Michael John), 1958- Eleven sedimentary and volcanic rock units are mapped and described in the thesis area, and chronicle the dynamic geologic history of the Tillamook embayment from the Oligocene through the middle Mlocene. The oldest unit is the Zemorrian to early Saucesian Smuggler Cove formation, a bathyal tuffaceous mudstone with some thin- to thick-bedded tuff layers deposited on the middle to upper continental slope during a period of explosive silicic volcanism in the Western Cascade arc. Uppermost Smuggler Cove strata are coarser grained, grading upward to arkosic turbidite sandstone and mudstone and thick bloturbated silty sandstone deposited on the outer shelf during marine regression. This regression heralded the progradation of the overlying shallow-marine Bewley Creek formation (informal) depositional system. The Bewley Creek formation (informal) is proposed in this study for a sequence of pumiceous, volcaniclastic-rich lower Miocene feldspathic litharenites and lithic arkoses deposited during the Pillarlan-stage near the mouth of an ancestral Columbia River. The unit grades from bioturbated silty sandstone to fine-grained hummocky cross-stratified and coarser grained channelized sandstones deposited within, or peripheral to a wave-dominated delta or ebb tidal-delta channel complex. Progradatlon of the Bewley Creek formation may have been caused, in part, by increased volcaniclastic sedimentation attending a pulse of explosive volcanism in the adjacent Western Cascade arc. Reduced volcanic activity, possibly coupled with basin subsidence or eustatic sea level rise, resulted in deposition of mudstones of the Sutton Creek member (informal; proposed) of the Nye Mudstone. The Saucesian Sutton Creek member consists of bathyal, laminated, carbonaceous, and moderately tuffaceous mudstone deposited in an upper continental slope basin. The upper part of the unit contains common lithic to arkosic turbidite sandstone interbeds within nested channel-fill deposits. These strata represent a channelized shelf-slope break environment adjacent to the shallow-marine Angora Peak member of the Astoria Formation depositlonal system. Subsequent marine regression resulted in progradation of the Pillarian- to Newportian-stage arkosic-micaceous sandstone-rich Angora Peak member into the Tillamook embayment. Grainsize analysis, sandstone petrography, scanning electron microscopy, and heavy mineral analyses suggest these lower to middle Miocene mollusk-bearing, fine- to medium-grained sandstones were predominantly deposited near the mouth of an ancestral Columbia River. They accumulated on a high-energy Inner shelf within or down drift of a wave-dominated delta or ebb-tidal delta complex, evidenced by paleocurrent analyses, hummocky cross-stratification and trough cross-stratified submarine channel-fill sequences. The Angora Peak member disconformably overlies Zemorrian mudstones of the Smuggler Cove formation at Cape Kiwanda suggesting local uplift and erosion in that area, followed by Newportian stage transgression in the Tillamook embayment. Exotic cobbles and boulders of two mica granite and sedimentary quartzite at Cape Kiwanda were probably derived from the Idaho Batholith and Precambrian sandstone terrains in Montana, transported via an ancestral Columbia River and longshore current to the shelf possibly bound within tree root bundles. The Netarts Bay member (informal) of the Astoria Formation Is proposed In this study for a late Sauceslan package of fine-grained to pebbly amalgamated and interbedded turbidite, grainflow, and fluldized flow friable thick-bedded lithic arkoses. These massive sandstones contain large penecontemporaneously emplaced channel wall-blocks and naller slltstone rip-ups. These lower to middle Miocene strata were deposited in a submarine canyon head and channel complex offshore of the shallow-marine Angora Peak member depositlonal system. Netarts Bay strata cut Into the underlying Angora Peak shelf strata, and cut and Interfinger with bathyal slope mudstones of the Cannon Beach member of the Astoria Formation. The overlying lower Cannon Beach member Is composed of laminated bathyal mudstones with rare turbidite sandstone interbeds deposited in a coarse clastic-starved slope environment. Upper Cannon Beach member strata In the Tillamook area are characterized by micaceous arkosic and lithic arkosic turbidite sandstones that underlie and occur within nested channel-fill sequences. Bloturbated carbonaceous cross-bedded sandstone In the upper Cannon Beach member records shallowing of the Tillamook embayment to a channelized upper slope to shelf environment. The Tillamook embayment was uplifted and dissected prior to the arrival of six to ten Intracanyon subaerial and submarine lava flows of the Columbia River Basalt Group. These middle Miocene flows, delineatedon the basis of geochemical composition and magnetic polarity, Include (in stratigraphic order) the Grouse Creek (R2 low MgO-low T102), Winterwater (N2 low MgO-low Ti02), and Sentinel Bluffs (high MgO) units of the Grande Ronde Basalt, and the Ginkgo unit of the Frenchman Springs member of the Wanapum Basalt. Orientation of Grande Ponde Basalt foreset-bedded pillow palagonite complexes and lava delta sequences indicate that these Columbia River Basalt units flowed westward into the Tillainook embayment, possibly through a saddle in the ancestral Oregon Coast Range. Marine transgression and deposition of hummocky cross-stratified arkosic marine strata of the Sandstone of Whale Cove followed emplacement of the last Grande Ronde flows. This was succeeded by a regression, as Indicated by the overlying subaerial plagioclase-phyric Ginkgo Unit flow of the Frenchman Springs Basalt. Locally, Winterwater and Sentinel Bluffs unit basalt occur as brecciated peperitic sills and dikes. These were emplaced through the process of "auto-invasion" when dense lava injected downward Into semi-lithifled Tertiary strata under the influence of both a pressure head augmented by flashing steam, and steam blasting. The thesis area is crossed by a complex network of high-angle northwest- and northeast-tending normal and reverse faults, and both low and high-angle east-trending reverse and thrust faults. These faults may have developed through a north-south compressional tectonic regime, a dextral shear couple, or a combination of these two tectonic regimes. Many faults cut Columbia River Basalt units and are thus middle Miocene or younger in age. Tertiary strata including the Columbia River Basalts are also folded within a broad westward-plunging syncline which suggests a middle Miocene or younger compressional event. Source rock analyses indicate that the mudstones of the Cannon Beach member, Sutton Creek member, and Smuggler Cove formation contain type III kerogen capable of generating natural gas only. Although these rocks have thermally innature vitrinite reflectance values, they contain sufficiently high total organic carbon content to be considered potential lean source rocks. Arkosic sandstones of the Angora Peak and Netarts Bay members have fair to good reservoir rock characteristics, and may represent reservoirs offshore for matured hydrocarbons generated from deeply buried source rocks. Close