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• 1. [Article] Stream temperatures, riparian vegetation, and channel morphology in the Upper Grande Ronde River Watershed, Oregon

  The Upper Grande Ronde River Watershed in northeastern Oregon is considered important habitat for threatened stocks of chinook salmon (Oncorhynchus tshawytscha). Documented reductions in channel complexity ...

  Citation × Citation Citation Abstract Copy Title: Stream temperatures, riparian vegetation, and channel morphology in the Upper Grande Ronde River Watershed, Oregon Author: Bohle, Todd S. The Upper Grande Ronde River Watershed in northeastern Oregon is considered important habitat for threatened stocks of chinook salmon (Oncorhynchus tshawytscha). Documented reductions in channel complexity and riparian vegetation within the watershed have increased concern over loss of viable habitat. An important component of salmonid habitat is stream temperature during critical summer periods. In general, annual maximum stream temperatures and diurnal fluctuations in the Upper Grande Ronde River were found to reflect local reach characteristics, position in the drainage, and large-scale changes in valley shape. Stream temperatures on the Grande Ronde River at a distance of 71 km from the watershed divide exceeded 14°C, the "upper preferred temperature" for chinook salmon, more than 90% of time in July of 1991 and in July and August of 1992. While the occurrence of temperatures above 14°C were less common in the headwaters of the Grande Ronde River, downstream of a large meadow (i.e., Vey Meadow) (29 km from the divide) 14°C was exceeded at least 60% of the time during the same three month period. Seven-day maximum stream temperatures on the Upper Grande Ronde River ranged between 17.9°C and 26.6°C in 1991 and between 19.1°C and 26.7°C in 1992. Diel fluctuations on the mainstem were greatest immediately below Vey Meadow (about 12°C) but tended to stabilize at approximately 8°C at distances of over 49 km from the divide. Maximum stream temperatures in tributaries of the Upper Grande Ronde River varied by as much as 11°C (during 1992), reflecting large differences in stream cover, aspect, and flow. The timing of annual maximums seemed to be strongly linked to aspect during 1992. In addition, the high-elevation, forested tributaries had annual maximum stream temperatures and diel fluctuations which were 3°C lower than those associated with more open, low-elevation sites. Relationships between stream temperatures, riparian vegetation, and channel morphology characteristics were evaluated for 11 tributary reaches. Differences in stream cover, average flow velocity, bankfull depth and percent undercut bank were found to be significantly (p <0.1) related to maximum stream temperatures and/or average August diel fluctuations based on linear regression models. A stream temperature prediction model (i.e., TEMP-86) was found to be an accurate predictor of average hourly strew temperatures through short 250-m long reaches. An average WSTAT (a measure of model accuracy) of -0.18°C was calculated based on 11 reaches though two reaches led to consistent over- and under-predictions of downstream temperatures. A series of temperature simulations using TEMP-86 and combinations of wetted width and percent stream cover suggest that lower maximum daily stream temperatures would be observed through altered reaches if concurrent changes in both parameters occurred. Title: Stream temperatures, riparian vegetation, and channel morphology in the Upper Grande Ronde River Watershed, Oregon Author: Bohle, Todd S. The Upper Grande Ronde River Watershed in northeastern Oregon is considered important habitat for threatened stocks of chinook salmon (Oncorhynchus tshawytscha). Documented reductions in channel complexity and riparian vegetation within the watershed have increased concern over loss of viable habitat. An important component of salmonid habitat is stream temperature during critical summer periods. In general, annual maximum stream temperatures and diurnal fluctuations in the Upper Grande Ronde River were found to reflect local reach characteristics, position in the drainage, and large-scale changes in valley shape. Stream temperatures on the Grande Ronde River at a distance of 71 km from the watershed divide exceeded 14°C, the "upper preferred temperature" for chinook salmon, more than 90% of time in July of 1991 and in July and August of 1992. While the occurrence of temperatures above 14°C were less common in the headwaters of the Grande Ronde River, downstream of a large meadow (i.e., Vey Meadow) (29 km from the divide) 14°C was exceeded at least 60% of the time during the same three month period. Seven-day maximum stream temperatures on the Upper Grande Ronde River ranged between 17.9°C and 26.6°C in 1991 and between 19.1°C and 26.7°C in 1992. Diel fluctuations on the mainstem were greatest immediately below Vey Meadow (about 12°C) but tended to stabilize at approximately 8°C at distances of over 49 km from the divide. Maximum stream temperatures in tributaries of the Upper Grande Ronde River varied by as much as 11°C (during 1992), reflecting large differences in stream cover, aspect, and flow. The timing of annual maximums seemed to be strongly linked to aspect during 1992. In addition, the high-elevation, forested tributaries had annual maximum stream temperatures and diel fluctuations which were 3°C lower than those associated with more open, low-elevation sites. Relationships between stream temperatures, riparian vegetation, and channel morphology characteristics were evaluated for 11 tributary reaches. Differences in stream cover, average flow velocity, bankfull depth and percent undercut bank were found to be significantly (p <0.1) related to maximum stream temperatures and/or average August diel fluctuations based on linear regression models. A stream temperature prediction model (i.e., TEMP-86) was found to be an accurate predictor of average hourly strew temperatures through short 250-m long reaches. An average WSTAT (a measure of model accuracy) of -0.18°C was calculated based on 11 reaches though two reaches led to consistent over- and under-predictions of downstream temperatures. A series of temperature simulations using TEMP-86 and combinations of wetted width and percent stream cover suggest that lower maximum daily stream temperatures would be observed through altered reaches if concurrent changes in both parameters occurred. Close

• 2. [Article] An economic comparison of alternative bluegrass residue management practices in Oregon's Grande Ronde Valley

  Published February 2009. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/cata...

  Citation × Citation Citation Abstract Copy Title: An economic comparison of alternative bluegrass residue management practices in Oregon's Grande Ronde Valley Author: Walenta, Darrin L., 1968-, Gow, Laura R., Diebel, Penelope L., 1961-, Oregon State University. Agricultural Experiment Station Published February 2009. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Title: An economic comparison of alternative bluegrass residue management practices in Oregon's Grande Ronde Valley Author: Walenta, Darrin L., 1968-, Gow, Laura R., Diebel, Penelope L., 1961-, Oregon State University. Agricultural Experiment Station Published February 2009. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog Close

• 3. [Article] Evaluation and cost analysis of alternative residue management methods for Kentucky bluegrass seed production in the Grande Ronde Valley

  The production of high quality grass seed is important to the agricultural economy of the Grande Ronde Valley (GRV) of eastern Oregon. The predominate grass seed crops grown in the area are Kentucky bluegrass ...

  Citation × Citation Citation Abstract Copy Title: Evaluation and cost analysis of alternative residue management methods for Kentucky bluegrass seed production in the Grande Ronde Valley Author: Walenta, Darrin L., 1968-, Diebel, Penelope L., 1961-, Gow, Laura R., Kiemnec, Gary L. The production of high quality grass seed is important to the agricultural economy of the Grande Ronde Valley (GRV) of eastern Oregon. The predominate grass seed crops grown in the area are Kentucky bluegrass and fine fescues. Historically, open-field burning has been an effective, economical means by which to remove residue and maintain seed yield and quality. The continued concern for air quality and public health have led to the adoption of alternative residue management methods that place less reliance on open-field burning of full straw residue loads. Title: Evaluation and cost analysis of alternative residue management methods for Kentucky bluegrass seed production in the Grande Ronde Valley Author: Walenta, Darrin L., 1968-, Diebel, Penelope L., 1961-, Gow, Laura R., Kiemnec, Gary L. The production of high quality grass seed is important to the agricultural economy of the Grande Ronde Valley (GRV) of eastern Oregon. The predominate grass seed crops grown in the area are Kentucky bluegrass and fine fescues. Historically, open-field burning has been an effective, economical means by which to remove residue and maintain seed yield and quality. The continued concern for air quality and public health have led to the adoption of alternative residue management methods that place less reliance on open-field burning of full straw residue loads. Close

• 4. [Article] From the Willamette to the Coast Range

  Citation × Citation Citation Abstract Copy Title: From the Willamette to the Coast Range Author: Adams, James Davis (J.D.) Title: From the Willamette to the Coast Range Author: Adams, James Davis (J.D.) Close

• 5. [Article] Ecological characteristics of montane floodplain plant communities in the Upper Grande Ronde basin, Oregon

  Citation × Citation Citation Abstract Copy Title: Ecological characteristics of montane floodplain plant communities in the Upper Grande Ronde basin, Oregon Author: Otting, Nicholas J. Title: Ecological characteristics of montane floodplain plant communities in the Upper Grande Ronde basin, Oregon Author: Otting, Nicholas J. Close

• 6. [Article] Historical changes in anadromous fish habitat in the Upper Grande Ronde River, Oregon, 1941-1990

  The U.S. Bureau of Fisheries (now National Marine Fisheries Service) conducted stream habitat surveys in the Upper Grande Ronde River Basin in 1941. This survey was part of an extensive inventory of stream ...

  Citation × Citation Citation Abstract Copy Title: Historical changes in anadromous fish habitat in the Upper Grande Ronde River, Oregon, 1941-1990 Author: McIntosh, Bruce A. The U.S. Bureau of Fisheries (now National Marine Fisheries Service) conducted stream habitat surveys in the Upper Grande Ronde River Basin in 1941. This survey was part of an extensive inventory of stream habitat conditions for anadromous salmonids (Oncorhynchus spp.) throughout the Columbia River Basin. The survey systematically inventoried 158 km of streams within the 3000 km2 watershed. Stream habitat was degraded from land-use activities (riparian timber harvest, splash dams, stream channelization, livestock grazing, and mining) prior to the 1941 survey. A 1990 resurvey determined how stream habitat conditions had continued to change. The historical survey and the 1990 resurvey inventoried streams according to pool and substrate characteristics. Pools were classified by size and depth criteria, while substrate was divided into size-classes. Losses in total pools/km (> 20m2 area and > 0.5 m depth) ranged from 43 to 83% (mean = 65%, 12.2 to 4.31km), while the loss in large pools/km (> 20m2 and > 1.0 m depth) ranged from 20 to 89% (mean = 68%, 6.2 to 2.0/1cm) for individual streams. The loss of variability in pool frequencies from 1941 to 1990 (total pools/km a2 = 43.9 to 2.8, large pools/km a2 = 23.2 to 3.2) demonstrates that stream channels have become less diverse. Classifying streams by reach types indicated that the decline in pool frequencies was not significantly related to geomorphic constraints. Substrate composition appears to have shifted toward smaller size-classes, with an increase in fine sediments (< 6mm) in the headwaters. Livestock grazing declined 78% (229,000 to 51,000 aum) from 1911 to 1990, while annual timber harvest increased 172% (36 to 98 mmbf) from the pre-survey period (1896-1940) to the post-survey period (1940-1990). Road densities have increased concurrent with timber harvest, currently averaging 4 miles/mile2. Base discharge has increased 51% (18.5 to 28.0 cfs), while there has been a 27% decrease in annual precipitation (22.0" to 16.0") and snowpack (April 1 water equivalent) (15.0" to 10.5") from 1941 to 1990. In an era of presumably improving management (1941-1990), large-scale losses in the fish habitat necessary for the continued viability of resident and anadromous fish populations continued to occur. Title: Historical changes in anadromous fish habitat in the Upper Grande Ronde River, Oregon, 1941-1990 Author: McIntosh, Bruce A. The U.S. Bureau of Fisheries (now National Marine Fisheries Service) conducted stream habitat surveys in the Upper Grande Ronde River Basin in 1941. This survey was part of an extensive inventory of stream habitat conditions for anadromous salmonids (Oncorhynchus spp.) throughout the Columbia River Basin. The survey systematically inventoried 158 km of streams within the 3000 km2 watershed. Stream habitat was degraded from land-use activities (riparian timber harvest, splash dams, stream channelization, livestock grazing, and mining) prior to the 1941 survey. A 1990 resurvey determined how stream habitat conditions had continued to change. The historical survey and the 1990 resurvey inventoried streams according to pool and substrate characteristics. Pools were classified by size and depth criteria, while substrate was divided into size-classes. Losses in total pools/km (> 20m2 area and > 0.5 m depth) ranged from 43 to 83% (mean = 65%, 12.2 to 4.31km), while the loss in large pools/km (> 20m2 and > 1.0 m depth) ranged from 20 to 89% (mean = 68%, 6.2 to 2.0/1cm) for individual streams. The loss of variability in pool frequencies from 1941 to 1990 (total pools/km a2 = 43.9 to 2.8, large pools/km a2 = 23.2 to 3.2) demonstrates that stream channels have become less diverse. Classifying streams by reach types indicated that the decline in pool frequencies was not significantly related to geomorphic constraints. Substrate composition appears to have shifted toward smaller size-classes, with an increase in fine sediments (< 6mm) in the headwaters. Livestock grazing declined 78% (229,000 to 51,000 aum) from 1911 to 1990, while annual timber harvest increased 172% (36 to 98 mmbf) from the pre-survey period (1896-1940) to the post-survey period (1940-1990). Road densities have increased concurrent with timber harvest, currently averaging 4 miles/mile2. Base discharge has increased 51% (18.5 to 28.0 cfs), while there has been a 27% decrease in annual precipitation (22.0" to 16.0") and snowpack (April 1 water equivalent) (15.0" to 10.5") from 1941 to 1990. In an era of presumably improving management (1941-1990), large-scale losses in the fish habitat necessary for the continued viability of resident and anadromous fish populations continued to occur. Close

• 7. [Article] Basin level ecological regions of the upper Grande Ronde River

  Citation × Citation Citation Abstract Copy Title: Basin level ecological regions of the upper Grande Ronde River Author: Thiele, Sandra Anne Title: Basin level ecological regions of the upper Grande Ronde River Author: Thiele, Sandra Anne Close

• 8. [Article] Year 2000 Timber Sales - Confederated Tribes on Grand Ronde : Biological Opinion

  The Natural Resources Division (NRD) of the Confederated Tribes of Grand Ronde (CTGR), in cooperation with the Bureau of Indian Affairs (BIA), proposes the regeneration harvest and commercial thinning ...

  Citation × Citation Citation Abstract Copy Title: Year 2000 Timber Sales - Confederated Tribes on Grand Ronde : Biological Opinion The Natural Resources Division (NRD) of the Confederated Tribes of Grand Ronde (CTGR), in cooperation with the Bureau of Indian Affairs (BIA), proposes the regeneration harvest and commercial thinning of four timber sales on the Reservation of The Confederated Tribes of Grand Ronde (CTGR). The CTGR has a 20-year management agreement with the BIA. For the purposes of this consultation the BIA is the action agency. The proposed timber harvest units are in the South Yamhill River subbasin, which supports two species listed by the National Marine Fisheries Service (NMFS) as threatened under the Federal Endangered Species Act (ESA). Upper Willamette River (UWR) chinook salmon (Oncorhynchus tshawytscha) were listed as threatened under the ESA on May 24, 1999. Upper Willamette River (UWR) steelhead (Oncorhynchus mykiss) were listed as threatened under the ESA on March 25, 1999. Critical habitat for both of these species was designated on February 16, 2000 (effective on March 17, 2000). According to the BA, UWR chinook do not currently reside in the action area and there is no recorded data indicating they were present historically. The nearest known occurrence of UWR chinook is near the confluence of Salt creek and the South Yamhill River, over 40 stream miles from the Reservation. Juvenile UWR steelhead reside within the action area and are known to occur in streams on the reservation. Based on the presence of juveniles, CTGR staff suspect that adult UWR steelhead spawn in streams on the Reservation, although little spawning survey work has been done. Title: Year 2000 Timber Sales - Confederated Tribes on Grand Ronde : Biological Opinion The Natural Resources Division (NRD) of the Confederated Tribes of Grand Ronde (CTGR), in cooperation with the Bureau of Indian Affairs (BIA), proposes the regeneration harvest and commercial thinning of four timber sales on the Reservation of The Confederated Tribes of Grand Ronde (CTGR). The CTGR has a 20-year management agreement with the BIA. For the purposes of this consultation the BIA is the action agency. The proposed timber harvest units are in the South Yamhill River subbasin, which supports two species listed by the National Marine Fisheries Service (NMFS) as threatened under the Federal Endangered Species Act (ESA). Upper Willamette River (UWR) chinook salmon (Oncorhynchus tshawytscha) were listed as threatened under the ESA on May 24, 1999. Upper Willamette River (UWR) steelhead (Oncorhynchus mykiss) were listed as threatened under the ESA on March 25, 1999. Critical habitat for both of these species was designated on February 16, 2000 (effective on March 17, 2000). According to the BA, UWR chinook do not currently reside in the action area and there is no recorded data indicating they were present historically. The nearest known occurrence of UWR chinook is near the confluence of Salt creek and the South Yamhill River, over 40 stream miles from the Reservation. Juvenile UWR steelhead reside within the action area and are known to occur in streams on the reservation. Based on the presence of juveniles, CTGR staff suspect that adult UWR steelhead spawn in streams on the Reservation, although little spawning survey work has been done. Close

• 9. [Article] Strontium isotopic and trace element geochemistry of the Saddle Mountains and Grande Rondé basalts of the Columbia River basalt group

  Citation × Citation Citation Abstract Copy Title: Strontium isotopic and trace element geochemistry of the Saddle Mountains and Grande Rondé basalts of the Columbia River basalt group Author: Nelson, Dennis O. Title: Strontium isotopic and trace element geochemistry of the Saddle Mountains and Grande Rondé basalts of the Columbia River basalt group Author: Nelson, Dennis O. Close

• 10. [Article] The geology of the Elk Mountain-Porter Ridge area, Clatsop County, northwest Oregon

  Eight Tertiary sedimentary and volcanic units crop out in the thesis area. From oldest to youngest they are the: Sager Creek formation (informal); Pittsburg Bluff Formation; Northrup Creek formation (informal); ...

  Citation × Citation Citation Abstract Copy Title: The geology of the Elk Mountain-Porter Ridge area, Clatsop County, northwest Oregon Author: Goalen, Jeffrey Scott Eight Tertiary sedimentary and volcanic units crop out in the thesis area. From oldest to youngest they are the: Sager Creek formation (informal); Pittsburg Bluff Formation; Northrup Creek formation (informal); Smuggler Cove formation (informal); Wickiup Mountain and Cannon Beach members (both informal) of the Astoria Formation; the Grande Ronde Basalt, and Frenchman Springs Member of the Wanapum Basalt, both of the Columbia River Basalt Group. Also, areally limited, unnamed sedimentary strata interbedded between flows of the Columbia River Basalt Group crop out in the study area. Quaternary deposits consist of alluvium, colluvium, and landslide debris. Rhythmically-bedded, foram-bearing, carbonaceous to micaceous mudstone and graded, fine-grained, feldspathic turbidite sandstone are the dominant lithologies of the upper Eocene (Refugian) Sager Creek formation. Plane-laminae and climbing ripple-laminae typical of Bouma b,c, and d intervals are common in the thin turbidite sandstone beds. Contemporaneous, rare, thick, sandstones may represent submarine feeder channels that supplied the more widespread, thinly-bedded overbank turbidite sandstones. Foraminiferal paleobathymetry indicates that deposition was in bathyal water depths. Sager Creek deposition was followed by a regression or offlap of the late Eocene to early Oligocene (Refugian) sea as indicated by the molluscan fossils and thick, bioturbated sandstone of the predominantly shallow-marine Pittsburg Bluff Formation. The lower part of the formation consists of outer shelf, glauconitic, fossiliferous sandstone and subordinate mudstone. Higher in the section are middle-shelf, fine-grained, bioturbated, tuffaceous, arkosic sandstones. These sandstones contain minor glauconite, wave- and storm-generated molluscan shell hash beds, carbonized wood fragments, and calcareous concretions. Deposition occurred in 20 - 50 m open-marine shelf water depths; however, the depositional environment may have shallowed to a bay-like setting (Moore, 1982, written communication). The upper part of the unit consists of thin- to medium-bedded, carbonaceous siltstone and mudstone with minor ashfall tuffs. Therefore, deposition of the Pittsburg Bluff Formation occurred as a shallowing-upward, then deepening depositional episode, punctuated by contemporaneous, intermittent eruption of nearby calc-alkaline western Cascade volcanoes. The deep-marine Oligocene to lower Miocene (Zemorrian to Saucesian) Northrup Creek formation is predominantly composed of thinly-laminated mudstone interbedded with thin, very fine-grained, graded, micaceous arkosic sandstone. Bouma c-d-e and a-b-e sequences are common in the turbidite sandstone; Bouma a-e intervals occur locally in sandstone/mudstone couplets. Paleocurrent indicators suggest that the predominant transport direction of these turbidite deposits was northeast to southwest. Abraded, carbonaceous plant debris and mica are abundant in the sandstone laminations. The upper part of the formation consists of thick, mollusk-bearing, moderately- to well-sorted, arkosic sandstone and minor polymict grit beds. A shallowing-upward, high-energy, shallow-marine shelf environment of deposition is indicated for the upper part of the formation. Contemporaneous with shelf and slope deposition of the Sager Creek, Pittsburg Bluff and Northrup Creek formations, the deep-water late Eocene to early Miocene Smuggler Cove formation was deposited as a distal or lateral correlative in a low-energy, outer shelf to slope setting. This foram-bearing unit consists of thick, bioturbated, bathyal, tuffaceous mudstone and siltstone with minor thin- to thick-bedded ashfall and current-reworked tuff. A marine onlap is indicated by the conformable relationship between the upper sandstone unit of the Northrup Creek formation and the overlying Smuggler Cove formation in the eastern part of the thesis area. The overlying lower to middle Miocene Astoria Formation contains two members in the thesis area: a high-energy, shallow shelf, fine- to medium-grained, fossiliferous, micaceous arkosic sandstone (Wickiup Mountain member), and an overlying, thinly-laminated, deepmarine mudstone (Cannon Beach member). Diatom floras indicate that a thermal "oceanographic irregularity" (water warmer than normal) may have occurred during deposition of the Cannon Beach member. At least six, and possibly eight, flows of the middle Miocene Grande Ronde Basalt (Columbia River Basalt Group) are present in the thesis area. Individual flows have been ascribed to the (N1?), R2, and N2 magnetozones. Geochemically, the flows consist of low MgO high Ti02, low MgO low Ti02, and high MgO subtypes. These subaerial to submarine flows are correlated to Mangan and others (1986) chemical subtypes 2D, 5C, 5A, and 4A of the Columbia Plateau-derived Grande Ronde Basalt of eastern Washington and eastern Oregon. The correlations are based on similarity of age, major element chemistry, stratigraphic position, and magnetic polarity. Field evidence suggests that thick, submarine pillow and breccia complexes generated sufficient pressure to autoinvasively inject into the Eocene to middle Miocene sedimentary strata of the Plympton/Porter ridge and Elk Mountain areas. This process apparently formed many randomly-oriented dike- and sill-like intrusions in the western part of the thesis area. However, in the eastern and central parts of the thesis area, three sub-parallel dikes (the Northrup, Beneke, and Fishhawk Falls dikes) extend along linear trends for tens of kilometers. This suggests that their emplacement was, in part, influenced by earlier or contemporaneous regional tectonism. At least two, and as many as five, flows of the Frenchman Springs Member of the Wanapum Basalt occur in the thesis area: one to two abundantly plagioclase-phyric Basalt of Ginkgo flow(s), and one to three Basalt of Sand Hollow flows (terminology after Beeson and Tolan, 1985). These flows consist of subaqueous pillow palagonite breccia and vesicular, columnar-jointed, subaerial basalt. No Frenchman Springs flows are invasive in the thesis area. Local middle Miocene sedimentary interbeds between flows of Grande Ronde and Frenchman Springs Basalt are lithologically and sedimentologically diverse. Common lithologies are fine- to mediumgrained, arkosic sandstone, coarse-grained basaltic sandstone, and structureless mudstone. Depositional environments represented by these strata are fluvial, marginal-marine, and shallow-marine. Thicknesses of individual interbeds range from 0.2 to 50 m. The thesis area is located on the northwest flank of the Oregon Coast Range anticline, adjacent to the Nehalem Arch. Large-scale northeast-trending oblique to strike-slip left-lateral faults coupled with northwest-trending oblique to strike-slip right-lateral faults dominate the structure of the area. These faults may have formed as conjugate shears (Riedel shear) caused by north-south compressive stress related to the oblique subduction of the Juan de Fuca Plate beneath the North American Plate. Five episodes of deformation are suggested by faults, dike orientations, unconformities, and other geological relationships within the thesis area: a late Eocene north-south compressional episode, an early Oligocene to early Miocene uplift, a middle Miocene northwest-southeast extensional episode, a post-middle Miocene to Pliocene (?) north-south compressional episode, and a north-south extensional event that occurred between the post-middle Miocene and Recent. Although crushed rock (for road and revetment construction) is currently the primary mineral resource within the thesis area, several potential fault traps on this northwest flank of the Nehalem Arch may contain significant reserves of natural gas. This conclusion is based upon field, laboratory, and subsurface (well) data. The Clark and Wilson sandstone of the middle to late Eocene Cowlitz Formation, the producing unit at the nearby Mist gas field, represents the most attractive target horizon. Additionally, the porous and permeable upper sandstone unit of the Northrup Creek formation could contain shallow hydrocarbon reserves beneath the northern part of the area. Title: The geology of the Elk Mountain-Porter Ridge area, Clatsop County, northwest Oregon Author: Goalen, Jeffrey Scott Eight Tertiary sedimentary and volcanic units crop out in the thesis area. From oldest to youngest they are the: Sager Creek formation (informal); Pittsburg Bluff Formation; Northrup Creek formation (informal); Smuggler Cove formation (informal); Wickiup Mountain and Cannon Beach members (both informal) of the Astoria Formation; the Grande Ronde Basalt, and Frenchman Springs Member of the Wanapum Basalt, both of the Columbia River Basalt Group. Also, areally limited, unnamed sedimentary strata interbedded between flows of the Columbia River Basalt Group crop out in the study area. Quaternary deposits consist of alluvium, colluvium, and landslide debris. Rhythmically-bedded, foram-bearing, carbonaceous to micaceous mudstone and graded, fine-grained, feldspathic turbidite sandstone are the dominant lithologies of the upper Eocene (Refugian) Sager Creek formation. Plane-laminae and climbing ripple-laminae typical of Bouma b,c, and d intervals are common in the thin turbidite sandstone beds. Contemporaneous, rare, thick, sandstones may represent submarine feeder channels that supplied the more widespread, thinly-bedded overbank turbidite sandstones. Foraminiferal paleobathymetry indicates that deposition was in bathyal water depths. Sager Creek deposition was followed by a regression or offlap of the late Eocene to early Oligocene (Refugian) sea as indicated by the molluscan fossils and thick, bioturbated sandstone of the predominantly shallow-marine Pittsburg Bluff Formation. The lower part of the formation consists of outer shelf, glauconitic, fossiliferous sandstone and subordinate mudstone. Higher in the section are middle-shelf, fine-grained, bioturbated, tuffaceous, arkosic sandstones. These sandstones contain minor glauconite, wave- and storm-generated molluscan shell hash beds, carbonized wood fragments, and calcareous concretions. Deposition occurred in 20 - 50 m open-marine shelf water depths; however, the depositional environment may have shallowed to a bay-like setting (Moore, 1982, written communication). The upper part of the unit consists of thin- to medium-bedded, carbonaceous siltstone and mudstone with minor ashfall tuffs. Therefore, deposition of the Pittsburg Bluff Formation occurred as a shallowing-upward, then deepening depositional episode, punctuated by contemporaneous, intermittent eruption of nearby calc-alkaline western Cascade volcanoes. The deep-marine Oligocene to lower Miocene (Zemorrian to Saucesian) Northrup Creek formation is predominantly composed of thinly-laminated mudstone interbedded with thin, very fine-grained, graded, micaceous arkosic sandstone. Bouma c-d-e and a-b-e sequences are common in the turbidite sandstone; Bouma a-e intervals occur locally in sandstone/mudstone couplets. Paleocurrent indicators suggest that the predominant transport direction of these turbidite deposits was northeast to southwest. Abraded, carbonaceous plant debris and mica are abundant in the sandstone laminations. The upper part of the formation consists of thick, mollusk-bearing, moderately- to well-sorted, arkosic sandstone and minor polymict grit beds. A shallowing-upward, high-energy, shallow-marine shelf environment of deposition is indicated for the upper part of the formation. Contemporaneous with shelf and slope deposition of the Sager Creek, Pittsburg Bluff and Northrup Creek formations, the deep-water late Eocene to early Miocene Smuggler Cove formation was deposited as a distal or lateral correlative in a low-energy, outer shelf to slope setting. This foram-bearing unit consists of thick, bioturbated, bathyal, tuffaceous mudstone and siltstone with minor thin- to thick-bedded ashfall and current-reworked tuff. A marine onlap is indicated by the conformable relationship between the upper sandstone unit of the Northrup Creek formation and the overlying Smuggler Cove formation in the eastern part of the thesis area. The overlying lower to middle Miocene Astoria Formation contains two members in the thesis area: a high-energy, shallow shelf, fine- to medium-grained, fossiliferous, micaceous arkosic sandstone (Wickiup Mountain member), and an overlying, thinly-laminated, deepmarine mudstone (Cannon Beach member). Diatom floras indicate that a thermal "oceanographic irregularity" (water warmer than normal) may have occurred during deposition of the Cannon Beach member. At least six, and possibly eight, flows of the middle Miocene Grande Ronde Basalt (Columbia River Basalt Group) are present in the thesis area. Individual flows have been ascribed to the (N1?), R2, and N2 magnetozones. Geochemically, the flows consist of low MgO high Ti02, low MgO low Ti02, and high MgO subtypes. These subaerial to submarine flows are correlated to Mangan and others (1986) chemical subtypes 2D, 5C, 5A, and 4A of the Columbia Plateau-derived Grande Ronde Basalt of eastern Washington and eastern Oregon. The correlations are based on similarity of age, major element chemistry, stratigraphic position, and magnetic polarity. Field evidence suggests that thick, submarine pillow and breccia complexes generated sufficient pressure to autoinvasively inject into the Eocene to middle Miocene sedimentary strata of the Plympton/Porter ridge and Elk Mountain areas. This process apparently formed many randomly-oriented dike- and sill-like intrusions in the western part of the thesis area. However, in the eastern and central parts of the thesis area, three sub-parallel dikes (the Northrup, Beneke, and Fishhawk Falls dikes) extend along linear trends for tens of kilometers. This suggests that their emplacement was, in part, influenced by earlier or contemporaneous regional tectonism. At least two, and as many as five, flows of the Frenchman Springs Member of the Wanapum Basalt occur in the thesis area: one to two abundantly plagioclase-phyric Basalt of Ginkgo flow(s), and one to three Basalt of Sand Hollow flows (terminology after Beeson and Tolan, 1985). These flows consist of subaqueous pillow palagonite breccia and vesicular, columnar-jointed, subaerial basalt. No Frenchman Springs flows are invasive in the thesis area. Local middle Miocene sedimentary interbeds between flows of Grande Ronde and Frenchman Springs Basalt are lithologically and sedimentologically diverse. Common lithologies are fine- to mediumgrained, arkosic sandstone, coarse-grained basaltic sandstone, and structureless mudstone. Depositional environments represented by these strata are fluvial, marginal-marine, and shallow-marine. Thicknesses of individual interbeds range from 0.2 to 50 m. The thesis area is located on the northwest flank of the Oregon Coast Range anticline, adjacent to the Nehalem Arch. Large-scale northeast-trending oblique to strike-slip left-lateral faults coupled with northwest-trending oblique to strike-slip right-lateral faults dominate the structure of the area. These faults may have formed as conjugate shears (Riedel shear) caused by north-south compressive stress related to the oblique subduction of the Juan de Fuca Plate beneath the North American Plate. Five episodes of deformation are suggested by faults, dike orientations, unconformities, and other geological relationships within the thesis area: a late Eocene north-south compressional episode, an early Oligocene to early Miocene uplift, a middle Miocene northwest-southeast extensional episode, a post-middle Miocene to Pliocene (?) north-south compressional episode, and a north-south extensional event that occurred between the post-middle Miocene and Recent. Although crushed rock (for road and revetment construction) is currently the primary mineral resource within the thesis area, several potential fault traps on this northwest flank of the Nehalem Arch may contain significant reserves of natural gas. This conclusion is based upon field, laboratory, and subsurface (well) data. The Clark and Wilson sandstone of the middle to late Eocene Cowlitz Formation, the producing unit at the nearby Mist gas field, represents the most attractive target horizon. Additionally, the porous and permeable upper sandstone unit of the Northrup Creek formation could contain shallow hydrocarbon reserves beneath the northern part of the area. Close

• 11. [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. Close

• 12. [Article] A spatially explicit model for allocating conservation efforts : the Grand Ronde River basin, Oregon

  The spatial and dynamic pattern of landscape changes has a profound effect on the supply of environmental services, including the provision of habitat for fish and wildlife. Spatial heterogeneity is a ...

  Citation × Citation Citation Abstract Copy Title: A spatially explicit model for allocating conservation efforts : the Grand Ronde River basin, Oregon Author: Watanabe, Michio The spatial and dynamic pattern of landscape changes has a profound effect on the supply of environmental services, including the provision of habitat for fish and wildlife. Spatial heterogeneity is a common feature of landscapes in the Pacific Northwest, most notably in areas important to the production of salmonid fish species. This heterogeneity complicates attempts to design and implement policies to conserve the stocks of such species. To date, millions of dollars have been spent to improve habitat for salmonids, with mixed success. This research examines the spatial implications of habitat restoration activities for the benefit of endangered salmonid fish species. A theoretical model defining an economically efficient allocation of restoration practices is developed for a hypothetical stream with a range of hydrological and spatial characteristics. An integrated hydrological, biological and economic modeling approach is then developed, and an empirical analysis is applied to the upper Grande Ronde River basin in northeastern Oregon. Results of these analyses indicate that the heterogeneous nature of riparian conditions and stream morphology has a substantial effect on the efficacy of restoration activities. The minimum cost allocation of restoration activities for small temperature reductions is to apply restoration efforts to nearby upstream reaches, while cumulative effects become important as the magnitude of desired temperature reduction increases. However, as the magnitude of desired temperature reductions increases, temperature reduction per dollar of restoration efforts decreases rapidly. In terms of specific riparian restoration efforts, passive restoration is preferred to active restoration as the magnitude of desired temperature reductions decreases and / or as the time frame considered is increased. It is also less costly in general to implement restoration activities in tributaries if the objective is to maximize stream length where water temperatures decrease by a specific amount. When two targeting options are compared (a fish abundance goal vs. a temperature reduction goal), this study found that temperature targeting is inefficient in the sense that it is possible to produce a larger salmonid population with the same budget, and that the levels of temperature targets have significant impacts on fishery benefits. Title: A spatially explicit model for allocating conservation efforts : the Grand Ronde River basin, Oregon Author: Watanabe, Michio The spatial and dynamic pattern of landscape changes has a profound effect on the supply of environmental services, including the provision of habitat for fish and wildlife. Spatial heterogeneity is a common feature of landscapes in the Pacific Northwest, most notably in areas important to the production of salmonid fish species. This heterogeneity complicates attempts to design and implement policies to conserve the stocks of such species. To date, millions of dollars have been spent to improve habitat for salmonids, with mixed success. This research examines the spatial implications of habitat restoration activities for the benefit of endangered salmonid fish species. A theoretical model defining an economically efficient allocation of restoration practices is developed for a hypothetical stream with a range of hydrological and spatial characteristics. An integrated hydrological, biological and economic modeling approach is then developed, and an empirical analysis is applied to the upper Grande Ronde River basin in northeastern Oregon. Results of these analyses indicate that the heterogeneous nature of riparian conditions and stream morphology has a substantial effect on the efficacy of restoration activities. The minimum cost allocation of restoration activities for small temperature reductions is to apply restoration efforts to nearby upstream reaches, while cumulative effects become important as the magnitude of desired temperature reduction increases. However, as the magnitude of desired temperature reductions increases, temperature reduction per dollar of restoration efforts decreases rapidly. In terms of specific riparian restoration efforts, passive restoration is preferred to active restoration as the magnitude of desired temperature reductions decreases and / or as the time frame considered is increased. It is also less costly in general to implement restoration activities in tributaries if the objective is to maximize stream length where water temperatures decrease by a specific amount. When two targeting options are compared (a fish abundance goal vs. a temperature reduction goal), this study found that temperature targeting is inefficient in the sense that it is possible to produce a larger salmonid population with the same budget, and that the levels of temperature targets have significant impacts on fishery benefits. Close

• 13. [Article] Feeder dikes to the Columbia River flood basalts : underpinnings of a large igneous province

  Feeder dikes to the Columbia River Basalt Group (CRBG) large igneous province provide a rare opportunity to examine magma transport through the shallow crust during flood basalt eruptions. Over 70% of ...

  Citation × Citation Citation Abstract Copy Title: Feeder dikes to the Columbia River flood basalts : underpinnings of a large igneous province Author: Petcovic, Heather L. Feeder dikes to the Columbia River Basalt Group (CRBG) large igneous province provide a rare opportunity to examine magma transport through the shallow crust during flood basalt eruptions. Over 70% of the CRBG erupted from the Chief Joseph dike swarm, which is exposed across southeastern Washington, eastern Oregon, and western Idaho. The four manuscripts of this dissertation examine physical, thermal, and compositional characteristics of dikes from the southern Chief Joseph swarm. The majority of CRBG dikes are chilled against their wallrock, however, rare dikes have induced partial melting in their wallrock. Melt zones in tonalite wallrock adjacent to the Maxwell Lake dike are up to 4 in thick and contain up to 47 volume percent quenched silicic melt produced from dehydration-melting reactions involvir biotite, hornblende, quartz, orthoclase, and plagioclase. Melt zones record the thermal history of basalt flow and cooling in the Maxwell Lake dike, a feeder to Wapshilla Ridge flows (Grande Ronde Basalt). Results of one- and two-dimensional numerical modeling suggest that basalt flowed in the Maxwell Lake dike for 3-4 years, yielding maximum eruption rates of 3.4-4.6 km3/day for typical Wapshilla Ridge flows. The Maxwell Lake dike likely represents an upper crustal exposure of a long-lived point source in the CRBG. Chief Joseph dikes are concentrated into sub-swarms of 7-12 dikes per km2. Based on transects through four sub-swarms, dikes become more aligned, more frequent, thinner, and more closely spaced from northwest to southeast across the southern Chief Joseph swarm. Fewer than 2% of dikes, and less than 0.5% of cumulative dike length, had caused extensive melting in their wallrock. In the Cornucopia sub-swarm, numerical modeling of cross-cutting and compound dikes suggests that magmatic activity occurred intermittently over 2-4 years. Compositional data collected from -250 southern Chief Joseph dikes indicate that most are Grande Ronde Basalt, although isolated Imnaha and Dodge (Eckler Mountain Member, Wanapum Basalt) dikes also occur. Imnaha dikes are compositionally primitive, whereas Grande Ronde and Dodge dikes are more evolved. Subtle compositional differences between sub-swarms of Grande Ronde dikes suggest that each sub-swarm represents a discrete episode of Grande Ronde volcanism. Title: Feeder dikes to the Columbia River flood basalts : underpinnings of a large igneous province Author: Petcovic, Heather L. Feeder dikes to the Columbia River Basalt Group (CRBG) large igneous province provide a rare opportunity to examine magma transport through the shallow crust during flood basalt eruptions. Over 70% of the CRBG erupted from the Chief Joseph dike swarm, which is exposed across southeastern Washington, eastern Oregon, and western Idaho. The four manuscripts of this dissertation examine physical, thermal, and compositional characteristics of dikes from the southern Chief Joseph swarm. The majority of CRBG dikes are chilled against their wallrock, however, rare dikes have induced partial melting in their wallrock. Melt zones in tonalite wallrock adjacent to the Maxwell Lake dike are up to 4 in thick and contain up to 47 volume percent quenched silicic melt produced from dehydration-melting reactions involvir biotite, hornblende, quartz, orthoclase, and plagioclase. Melt zones record the thermal history of basalt flow and cooling in the Maxwell Lake dike, a feeder to Wapshilla Ridge flows (Grande Ronde Basalt). Results of one- and two-dimensional numerical modeling suggest that basalt flowed in the Maxwell Lake dike for 3-4 years, yielding maximum eruption rates of 3.4-4.6 km3/day for typical Wapshilla Ridge flows. The Maxwell Lake dike likely represents an upper crustal exposure of a long-lived point source in the CRBG. Chief Joseph dikes are concentrated into sub-swarms of 7-12 dikes per km2. Based on transects through four sub-swarms, dikes become more aligned, more frequent, thinner, and more closely spaced from northwest to southeast across the southern Chief Joseph swarm. Fewer than 2% of dikes, and less than 0.5% of cumulative dike length, had caused extensive melting in their wallrock. In the Cornucopia sub-swarm, numerical modeling of cross-cutting and compound dikes suggests that magmatic activity occurred intermittently over 2-4 years. Compositional data collected from -250 southern Chief Joseph dikes indicate that most are Grande Ronde Basalt, although isolated Imnaha and Dodge (Eckler Mountain Member, Wanapum Basalt) dikes also occur. Imnaha dikes are compositionally primitive, whereas Grande Ronde and Dodge dikes are more evolved. Subtle compositional differences between sub-swarms of Grande Ronde dikes suggest that each sub-swarm represents a discrete episode of Grande Ronde volcanism. Close

• 14. [Article] Evaluating the restoration potential of black cottonwood (Populus trichocarpa) from multiple scales of observation, Grande Ronde River Basin, Oregon, USA

  As a key factor contributing to slope stability, in-stream habitat for aquatic species (e.g., salmonids), nutrient cycling, and corridors for upland species, riparian vegetation and its maintenance is ...

  Citation × Citation Citation Abstract Copy Title: Evaluating the restoration potential of black cottonwood (Populus trichocarpa) from multiple scales of observation, Grande Ronde River Basin, Oregon, USA Author: Hines, Cynthia A. As a key factor contributing to slope stability, in-stream habitat for aquatic species (e.g., salmonids), nutrient cycling, and corridors for upland species, riparian vegetation and its maintenance is of critical conservation importance. Subsequently, the chronic degradation of aquatic and riparian ecosystems in the semi-arid and arid landscapes of the western U.S. is the focus of many recent research efforts. A study was undertaken to investigate historic and current black cottonwood populations in the Grande Ronde River Basin, northeastern Oregon, U.S.A., and evaluate restoration potential given present-day fluvial-geomorphic conditions and reproductive strategies. Black cottonwood (Populus trichocarpa), a dominant tree species in these semi-arid systems, has been severely impacted by intensive grazing, irrigation, and land conversion activities over the past one and a half centuries. With the explicit incorporation of space and time, a simple conceptual framework was developed to examine the ecological restoration potential of black cottonwood from ecological and evolutionary perspectives. Restoration potential is defined in this study in terms of availability of suitable habitat and source (i.e., seedpool) for future generations. Digital analyses of aerial photographs reveal changes in the extent, numbers, and total area of cottonwood communities and habitat since 1937. Restoration potential is evaluated using historic stream flow records, stream cross-section analysis to predict current stream discharge, and DNA RAPD procedures to assess the effects of changing stream geomorphology and disturbance regimes on cottonwood reproductive strategies. Optimal spatial and temporal conditions for potential restoration locations of black cottonwood have been identified relative to channel morphology and flood events (e.g., frequency and magnitude). This multiple scale mechnistic approach is used to evaluate the feasibility of restoration efforts toward the re-establishment of viable black cottonwood riparian plant communities in two sites in the upper Grande Ronde River Basin. Title: Evaluating the restoration potential of black cottonwood (Populus trichocarpa) from multiple scales of observation, Grande Ronde River Basin, Oregon, USA Author: Hines, Cynthia A. As a key factor contributing to slope stability, in-stream habitat for aquatic species (e.g., salmonids), nutrient cycling, and corridors for upland species, riparian vegetation and its maintenance is of critical conservation importance. Subsequently, the chronic degradation of aquatic and riparian ecosystems in the semi-arid and arid landscapes of the western U.S. is the focus of many recent research efforts. A study was undertaken to investigate historic and current black cottonwood populations in the Grande Ronde River Basin, northeastern Oregon, U.S.A., and evaluate restoration potential given present-day fluvial-geomorphic conditions and reproductive strategies. Black cottonwood (Populus trichocarpa), a dominant tree species in these semi-arid systems, has been severely impacted by intensive grazing, irrigation, and land conversion activities over the past one and a half centuries. With the explicit incorporation of space and time, a simple conceptual framework was developed to examine the ecological restoration potential of black cottonwood from ecological and evolutionary perspectives. Restoration potential is defined in this study in terms of availability of suitable habitat and source (i.e., seedpool) for future generations. Digital analyses of aerial photographs reveal changes in the extent, numbers, and total area of cottonwood communities and habitat since 1937. Restoration potential is evaluated using historic stream flow records, stream cross-section analysis to predict current stream discharge, and DNA RAPD procedures to assess the effects of changing stream geomorphology and disturbance regimes on cottonwood reproductive strategies. Optimal spatial and temporal conditions for potential restoration locations of black cottonwood have been identified relative to channel morphology and flood events (e.g., frequency and magnitude). This multiple scale mechnistic approach is used to evaluate the feasibility of restoration efforts toward the re-establishment of viable black cottonwood riparian plant communities in two sites in the upper Grande Ronde River Basin. Close

• 15. [Article] The ecology of riparian ecosystems of Northeast Oregon : shrub recovery at Meadow Creek and the structure and biomass of headwater Upper Grande Ronde ecosystems

  Riparian ecosystems play numerous and essential roles related to the quality and flow of water, and food/habitat for fish, and varieties of wildlife. Due to lateral and linear linkages throughout the landscape, ...

  Citation × Citation Citation Abstract Copy Title: The ecology of riparian ecosystems of Northeast Oregon : shrub recovery at Meadow Creek and the structure and biomass of headwater Upper Grande Ronde ecosystems Author: Case, Richard L. Riparian ecosystems play numerous and essential roles related to the quality and flow of water, and food/habitat for fish, and varieties of wildlife. Due to lateral and linear linkages throughout the landscape, these zones influence the integrity of the terrestrial as well as the entire aquatic-riverine ecosystem. Since Euro-American settlement in the West, the structure and condition of many riparian ecosystems has been significantly altered. To provide tools and an ecological perspective related to riparian restoration and management, and to document late 20th century headwater riparian structure and biomass in the Upper Grande Ronde Basin, this research project was undertaken. At Meadow Creek, the response of riparian hardwood species to the termination of livestock grazing was quantified. Regression equations were developed to predict shrub biomass. Permanently marked hardwood plants were measured annually to quantify parameters of growth (height, crown area, mainstem diameter, number of stems, biomass). Permanent belt transects on gravel bars were utilized to quantify rates of shrub establishment. Elk/deer-proof exclosures allowed the quantification of the browsing influence of wild ungulates. In 1991, initial shrub heights and densities reflected decades of grazing pressure. Mean heights of515 woody plants (14 species) was 47 cm and densities on gravel bars averaged 10.7 plants/100m². After two seasons without livestock grazing, mean crown volumes of willows (Salix spp.) increased 550% inside of wild ungulate exclosures and 195% outside, black cottonwood (Populus trichocarpa) 773% inside and 808% outside, and thin-leaf alder (Almis incana) 1046% inside and 198% outside, respectively. Willows were significantly impeded (p<0.Ol) mule deer and Rocky Mountain elk, alder samples were too small to statistically test, and cottonwood was not significantly impeded. However, impacts by deer and elk may be exaggerated due to high densities and the ungulate density-dynamics unique within the 77 km² Starkey Experimental Forest big-game enclosure surrounding the study site. Establishment rates are low at this time, i.e., only 10% of previously suppressed willows produced catkins. Although in transects densities increased by 5 new woody plants/lOOm² (50m of streambank). Other non-anthropogenic factors influencing the recovery of shrubs, included beaver which removed mainstems from 20% of willows, 11% of thin-leaf alder, and 4% of black cottonwood, and active insect defoliation which was noted on 16% of willows, 7% of thin-leaf alder, and 0% of black cottonwood. Crude protein levels measured in willow and alder leaves was relatively high (16.1 to 16.3%) helping to explain their palatability and use by wild and domestic herbivores. Few studies have quantified biomass, structure and composition of headwater riparian ecosystems. Data such as this are important given their dominant roles in ecosystem biodiversity, and aquatic function. To document relatively intact forested headwater ripanan conditions in the Upper Grande Ronde Basin, the biomass, structure and composition along six headwater reaches was quantified. Sampling was done using a nested belt transect/plot arrangement along 500 meter reaches. Total aboveground biomass (TAGB) ranged from 203 to 261 Mg/ha, with overstory conifers contributing 101 to 177 Mg/ha. Living understory components (saplings, seedlings, shrubs, and herbs) comprised 5 to 18 Mg/ha (2 to 9% of TAGB), while forest floor detrital accumulations comprised 65 to 101 Mg/ha (29 to 42% of TAGB). Average shade per day for July, 1993 ranged between 53% and 75%, reducing the unshaded solar energy potential of 2390 Mj/day to between 680 and 1280 Mj/day striking each m² of stream surface. This baseline reference information can serve in multi-disciplined research, as well as, be a basis for long term studies of natural systems responding to changing climate and different resource management scenarios. Title: The ecology of riparian ecosystems of Northeast Oregon : shrub recovery at Meadow Creek and the structure and biomass of headwater Upper Grande Ronde ecosystems Author: Case, Richard L. Riparian ecosystems play numerous and essential roles related to the quality and flow of water, and food/habitat for fish, and varieties of wildlife. Due to lateral and linear linkages throughout the landscape, these zones influence the integrity of the terrestrial as well as the entire aquatic-riverine ecosystem. Since Euro-American settlement in the West, the structure and condition of many riparian ecosystems has been significantly altered. To provide tools and an ecological perspective related to riparian restoration and management, and to document late 20th century headwater riparian structure and biomass in the Upper Grande Ronde Basin, this research project was undertaken. At Meadow Creek, the response of riparian hardwood species to the termination of livestock grazing was quantified. Regression equations were developed to predict shrub biomass. Permanently marked hardwood plants were measured annually to quantify parameters of growth (height, crown area, mainstem diameter, number of stems, biomass). Permanent belt transects on gravel bars were utilized to quantify rates of shrub establishment. Elk/deer-proof exclosures allowed the quantification of the browsing influence of wild ungulates. In 1991, initial shrub heights and densities reflected decades of grazing pressure. Mean heights of515 woody plants (14 species) was 47 cm and densities on gravel bars averaged 10.7 plants/100m². After two seasons without livestock grazing, mean crown volumes of willows (Salix spp.) increased 550% inside of wild ungulate exclosures and 195% outside, black cottonwood (Populus trichocarpa) 773% inside and 808% outside, and thin-leaf alder (Almis incana) 1046% inside and 198% outside, respectively. Willows were significantly impeded (p<0.Ol) mule deer and Rocky Mountain elk, alder samples were too small to statistically test, and cottonwood was not significantly impeded. However, impacts by deer and elk may be exaggerated due to high densities and the ungulate density-dynamics unique within the 77 km² Starkey Experimental Forest big-game enclosure surrounding the study site. Establishment rates are low at this time, i.e., only 10% of previously suppressed willows produced catkins. Although in transects densities increased by 5 new woody plants/lOOm² (50m of streambank). Other non-anthropogenic factors influencing the recovery of shrubs, included beaver which removed mainstems from 20% of willows, 11% of thin-leaf alder, and 4% of black cottonwood, and active insect defoliation which was noted on 16% of willows, 7% of thin-leaf alder, and 0% of black cottonwood. Crude protein levels measured in willow and alder leaves was relatively high (16.1 to 16.3%) helping to explain their palatability and use by wild and domestic herbivores. Few studies have quantified biomass, structure and composition of headwater riparian ecosystems. Data such as this are important given their dominant roles in ecosystem biodiversity, and aquatic function. To document relatively intact forested headwater ripanan conditions in the Upper Grande Ronde Basin, the biomass, structure and composition along six headwater reaches was quantified. Sampling was done using a nested belt transect/plot arrangement along 500 meter reaches. Total aboveground biomass (TAGB) ranged from 203 to 261 Mg/ha, with overstory conifers contributing 101 to 177 Mg/ha. Living understory components (saplings, seedlings, shrubs, and herbs) comprised 5 to 18 Mg/ha (2 to 9% of TAGB), while forest floor detrital accumulations comprised 65 to 101 Mg/ha (29 to 42% of TAGB). Average shade per day for July, 1993 ranged between 53% and 75%, reducing the unshaded solar energy potential of 2390 Mj/day to between 680 and 1280 Mj/day striking each m² of stream surface. This baseline reference information can serve in multi-disciplined research, as well as, be a basis for long term studies of natural systems responding to changing climate and different resource management scenarios. Close

• 16. [Article] Oregon State Game Commission bulletin; Vol.22 No.6 (November-December 1967)

  Contents: Senate Bill 8 Becomes Law - p.2; Can You Tell Me? [Receiving inquiries about fishing and hunting regulations] - p.3, 7-8; Steelhead Fishing Grande Ronde River - p.4-5; Cougar [Photos] - p.6; ...

  Citation × Citation Citation Abstract Copy Title: Oregon State Game Commission bulletin; Vol.22 No.6 (November-December 1967) Author: Oregon. State Game Commission Contents: Senate Bill 8 Becomes Law - p.2; Can You Tell Me? [Receiving inquiries about fishing and hunting regulations] - p.3, 7-8; Steelhead Fishing Grande Ronde River - p.4-5; Cougar [Photos] - p.6; The California Murre - p.8 Title: Oregon State Game Commission bulletin; Vol.22 No.6 (November-December 1967) Author: Oregon. State Game Commission Contents: Senate Bill 8 Becomes Law - p.2; Can You Tell Me? [Receiving inquiries about fishing and hunting regulations] - p.3, 7-8; Steelhead Fishing Grande Ronde River - p.4-5; Cougar [Photos] - p.6; The California Murre - p.8 Close

• 17. [Article] Results of trip to Snake River : 28 September -- 4 October 1957

  The mail boat trip was taken from Lewiston to Hells Canyon and return. Bathythermograph observations were made in deep holes at Buffalo Eddy, Nez Perce Dam site, and near Mountain Sheep Dam site. Thermograph ...

  Citation × Citation Citation Abstract Copy Title: Results of trip to Snake River : 28 September -- 4 October 1957 Author: Oregon State College. School of Science, Burt, Wayne V., U.S. Fish and Wildlife Service The mail boat trip was taken from Lewiston to Hells Canyon and return. Bathythermograph observations were made in deep holes at Buffalo Eddy, Nez Perce Dam site, and near Mountain Sheep Dam site. Thermograph sites on the Grande Ronde River were evaluated. A number of lakes, reservoirs, and dams were visited enroute to Lewiston. Title: Results of trip to Snake River : 28 September -- 4 October 1957 Author: Oregon State College. School of Science, Burt, Wayne V., U.S. Fish and Wildlife Service The mail boat trip was taken from Lewiston to Hells Canyon and return. Bathythermograph observations were made in deep holes at Buffalo Eddy, Nez Perce Dam site, and near Mountain Sheep Dam site. Thermograph sites on the Grande Ronde River were evaluated. A number of lakes, reservoirs, and dams were visited enroute to Lewiston. Close

• 18. [Article] Ecology of woody riparian vegetation in tributaries of the Upper Grande Ronde River basin, Oregon

  Two studies on Catherine Creek and Meadow Creek of the Upper Grande Ronde River basin, quantified several physical and biotic influences on woody riparian community composition and structure. The Catherine ...

  Citation × Citation Citation Abstract Copy Title: Ecology of woody riparian vegetation in tributaries of the Upper Grande Ronde River basin, Oregon Author: Lytjen, Danna J. Two studies on Catherine Creek and Meadow Creek of the Upper Grande Ronde River basin, quantified several physical and biotic influences on woody riparian community composition and structure. The Catherine Creek study examined the association of woody riparian species with elevational and geomorphic gradients. The Meadow Creek study examined the influence of mammal herbivory on composition and abundance of woody riparian species. At Catherine Creek, twenty nine plots were established at 50 m intervals of elevation from near the stream origin at 2207 m in the Wallowa Mountains to the foothills of the Grande Ronde Valley at 988 m. Woody plant community composition was associated with the dominant environmental variable, elevation. Distribution of dominant riparian species was strongly associated with fluvial surfaces. Black cottonwood (Populus balsamifera) was associated with gravel and cobble bars proximal to the stream channel, and along with ponderosa pine (Pinus ponderosa) was also associated with elevated boulder bars. Alders (A. incana and A. viridis) and willows (Salix bebbiana, S. boothii, S. exigua, S. lucida, S. melanopsis, S. prolixa, and S. sitchensis) were associated with annual floodplains. At Meadow Creek, grazing by cattle was ended in 1991 on the entire study reach and three deer and elk exclosures were built within the reach adjacent to the creek. Inside deer/elk exclosures from 1991 to 1995, mean heights of tagged cottonwoods, willows, and alders increased by 86% to 180%. Outside exclosures, mean heights of cottonwoods and alders increased 109% and 99% respectively, but willows showed little change in height. Both inside and outside of exclosures mean crown volume of cottonwoods increased over 1000% and mean crown volume of alders increased over 600%. Willow volume inside exclosures increased 376% in root sprouting (clonal) species and 528% in crown sprouting (non-clonal) species, while outside of exclosures volume increased 79% and 144% respectively. On both sides of exclosure fences, beaver herbivory had a significant effect on cottonwood height growth in 1994 and 1995, and on height and crown volume growth of willows in 1995. Over 50% of stem density increase on transects was attributable to expansion within two large clones of Salix melanopsis inside exclosures. Excluding these two clones, overall woody plant density increased by 72% from 3.7 plants per 100 m² of transect in 1991 to 6.3 plants per 100 m² of transect in 1995. Title: Ecology of woody riparian vegetation in tributaries of the Upper Grande Ronde River basin, Oregon Author: Lytjen, Danna J. Two studies on Catherine Creek and Meadow Creek of the Upper Grande Ronde River basin, quantified several physical and biotic influences on woody riparian community composition and structure. The Catherine Creek study examined the association of woody riparian species with elevational and geomorphic gradients. The Meadow Creek study examined the influence of mammal herbivory on composition and abundance of woody riparian species. At Catherine Creek, twenty nine plots were established at 50 m intervals of elevation from near the stream origin at 2207 m in the Wallowa Mountains to the foothills of the Grande Ronde Valley at 988 m. Woody plant community composition was associated with the dominant environmental variable, elevation. Distribution of dominant riparian species was strongly associated with fluvial surfaces. Black cottonwood (Populus balsamifera) was associated with gravel and cobble bars proximal to the stream channel, and along with ponderosa pine (Pinus ponderosa) was also associated with elevated boulder bars. Alders (A. incana and A. viridis) and willows (Salix bebbiana, S. boothii, S. exigua, S. lucida, S. melanopsis, S. prolixa, and S. sitchensis) were associated with annual floodplains. At Meadow Creek, grazing by cattle was ended in 1991 on the entire study reach and three deer and elk exclosures were built within the reach adjacent to the creek. Inside deer/elk exclosures from 1991 to 1995, mean heights of tagged cottonwoods, willows, and alders increased by 86% to 180%. Outside exclosures, mean heights of cottonwoods and alders increased 109% and 99% respectively, but willows showed little change in height. Both inside and outside of exclosures mean crown volume of cottonwoods increased over 1000% and mean crown volume of alders increased over 600%. Willow volume inside exclosures increased 376% in root sprouting (clonal) species and 528% in crown sprouting (non-clonal) species, while outside of exclosures volume increased 79% and 144% respectively. On both sides of exclosure fences, beaver herbivory had a significant effect on cottonwood height growth in 1994 and 1995, and on height and crown volume growth of willows in 1995. Over 50% of stem density increase on transects was attributable to expansion within two large clones of Salix melanopsis inside exclosures. Excluding these two clones, overall woody plant density increased by 72% from 3.7 plants per 100 m² of transect in 1991 to 6.3 plants per 100 m² of transect in 1995. Close

• 19. [Article] Revegetation with Carex nebrascensis and Carex utriculata following reconstruction in a NE Oregon meadow stream

  Riparian vegetation is an essential component for the maintenance and/or repair of channel stability and function. Sedges within low-gradient riparian systems provide the structure necessary for sediment ...

  Citation × Citation Citation Abstract Copy Title: Revegetation with Carex nebrascensis and Carex utriculata following reconstruction in a NE Oregon meadow stream Author: Quistberg, Sarah E. Riparian vegetation is an essential component for the maintenance and/or repair of channel stability and function. Sedges within low-gradient riparian systems provide the structure necessary for sediment trapping leading to channel narrowing through bank building processes. Planting success in riparian restoration projects has often failed due to inappropriate species selection, planting locations and/or methodologies. Stream restoration efforts utilizing channel reconstruction methods are increasing in number across the West thus emphasizing the need for knowledge on revegetation methods. Planting success in a recently constructed channel is essential because the lack of vegetation makes the channel highly susceptible to erosion. Sedges play an important role in the stability of low gradient, fine-textured stream channels. Two native sedges, Carex nebrascensis (Nebraska sedge) and Carex utriculata (beaked sedge) are often used in riparian restoration within the West because they have extensive root systems that can provide bank stability in fine-sediment channels. Survival and vegetative reproduction were evaluated on greenhouse grown plugs of these two sedge species following transplanting within a reconstructed NE Oregon meadow stream. Sedge plugs were planted on two fluvial surfaces along the stream: depositional (point bars) and erosional surfaces (straight) at or below bankfull level. A second study was performed to evaluate the effect of Cirsium arvense (Canada thistle) presence on sedge transplant survival and vegetative reproduction. This was performed only on erosional planting locations. Depths to groundwater and soil moisture were also recorded at each planting location. Survival at the end of the first growing season in the first study was the same for both species, but shoot numbers were greater for Carex nebrascensis (98 shoots/m²) compared with Carex utriculata (84 shoots/m²). No differences were observed between shoot numbers by species at the end of the second growing season. Greater shoot numbers also occurred on depositional planting locations (117 and 165 shoots/m²) compared to erosional planting locations (65 and 59 shoots/m²) at the end of the first and second growing seasons. Transplant loss due to scour from high flows was greater at erosional planting locations (48%) than at depositional planting surfaces (19%). Sedge transplant loss from scour during high flows was greater for Carex utriculata transplants (44%) than for Carex nebrascensis transplants (23%). Presence of Cirsium arvense was observed to be associated with a reduction in vegetative reproduction during the first growing season but not at the end of the second growing season. Carex nebrascensis produced more shoots than Carex utriculata regardless of thistle presence for both growing seasons probably due to depth to groundwater. Transplant loss due to scour from high flows was greater for Carex utriculata (55%) compared to Carex nebrascensis (28%). These results suggested that revegetation success will be increased if sedges are planted on depositional geomorphic surfaces within reconstructed meadow channels. Cirsium arvense may be controlled following sedge transplanting during the first growing season to increase vegetative growth. These results also suggested that Carex nebrascensis is an appropriate species for transplanting at sites with water tables deeper than 30 cm. Title: Revegetation with Carex nebrascensis and Carex utriculata following reconstruction in a NE Oregon meadow stream Author: Quistberg, Sarah E. Riparian vegetation is an essential component for the maintenance and/or repair of channel stability and function. Sedges within low-gradient riparian systems provide the structure necessary for sediment trapping leading to channel narrowing through bank building processes. Planting success in riparian restoration projects has often failed due to inappropriate species selection, planting locations and/or methodologies. Stream restoration efforts utilizing channel reconstruction methods are increasing in number across the West thus emphasizing the need for knowledge on revegetation methods. Planting success in a recently constructed channel is essential because the lack of vegetation makes the channel highly susceptible to erosion. Sedges play an important role in the stability of low gradient, fine-textured stream channels. Two native sedges, Carex nebrascensis (Nebraska sedge) and Carex utriculata (beaked sedge) are often used in riparian restoration within the West because they have extensive root systems that can provide bank stability in fine-sediment channels. Survival and vegetative reproduction were evaluated on greenhouse grown plugs of these two sedge species following transplanting within a reconstructed NE Oregon meadow stream. Sedge plugs were planted on two fluvial surfaces along the stream: depositional (point bars) and erosional surfaces (straight) at or below bankfull level. A second study was performed to evaluate the effect of Cirsium arvense (Canada thistle) presence on sedge transplant survival and vegetative reproduction. This was performed only on erosional planting locations. Depths to groundwater and soil moisture were also recorded at each planting location. Survival at the end of the first growing season in the first study was the same for both species, but shoot numbers were greater for Carex nebrascensis (98 shoots/m²) compared with Carex utriculata (84 shoots/m²). No differences were observed between shoot numbers by species at the end of the second growing season. Greater shoot numbers also occurred on depositional planting locations (117 and 165 shoots/m²) compared to erosional planting locations (65 and 59 shoots/m²) at the end of the first and second growing seasons. Transplant loss due to scour from high flows was greater at erosional planting locations (48%) than at depositional planting surfaces (19%). Sedge transplant loss from scour during high flows was greater for Carex utriculata transplants (44%) than for Carex nebrascensis transplants (23%). Presence of Cirsium arvense was observed to be associated with a reduction in vegetative reproduction during the first growing season but not at the end of the second growing season. Carex nebrascensis produced more shoots than Carex utriculata regardless of thistle presence for both growing seasons probably due to depth to groundwater. Transplant loss due to scour from high flows was greater for Carex utriculata (55%) compared to Carex nebrascensis (28%). These results suggested that revegetation success will be increased if sedges are planted on depositional geomorphic surfaces within reconstructed meadow channels. Cirsium arvense may be controlled following sedge transplanting during the first growing season to increase vegetative growth. These results also suggested that Carex nebrascensis is an appropriate species for transplanting at sites with water tables deeper than 30 cm. Close

• 20. [Article] The geology of the Nicolai Mountain-Gnat Creek area, Clatsop County, northwestern Oregon

  Twelve rock units, from upper Eocene to middle Miocene are exposed in the Nicolai Mountain-Gnat Creek area. They are, from oldest to youngest: Pittsburg Bluff Formation; Oswald West mudstone; Big Creek ...

  Citation × Citation Citation Abstract Copy Title: The geology of the Nicolai Mountain-Gnat Creek area, Clatsop County, northwestern Oregon Author: Murphy, Thomas M. Twelve rock units, from upper Eocene to middle Miocene are exposed in the Nicolai Mountain-Gnat Creek area. They are, from oldest to youngest: Pittsburg Bluff Formation; Oswald West mudstone; Big Creek sandstone, upper Silver Point mudstone, and Pipeline mudstone members of the Astoria Formation; Depoe Bay Basalt; Grande Ronde Basalt; Cape Foulweather Basalt; and sandstone correlative to the Vantage Member of the Ellensburg Formation; Frenchman Springs Member of the Wanapum Basalt; Clifton, Formation (defined by author); and Pomona Member of the Saddle Mountains Basalt. Upper Eocene Pittsburg Bluff Formation is a fine-grained sandstone and laminated siltstone deposited in an inner to middle continental shelf environment. Concordant onlapping by the upper Oligocene, middle shelf to upper slope glauconitic Oswald West mudstone, establishes a tie between the northeastern and northwestern Oregon Coast Range stratigraphies. The lower to middle Miocene Astoria Formation represents another marine onlap sequence, beginning with the fine-grained cross-bedded inner shelf Big Creek sandstone member. The overlying laminted upper Silver Point and Pipeline mudstone members were deposited in a deepening middle shelf to upper slope environment. The middle Miocene tholeiitic basalts extruded from two sources. Grande Ronde, Frenchman Springs, and Pomona basalts of the Columbia River Group erupted from fissures east of the Cascades and flowed down an ancestral Columbia River valley entering the sea in the study area. Simultaneously, petrologically similar but less voluminous Depoe Bay and Cape Foulweather are correlative to the low MgO Grande Ronde and Frenchman Springs in the study area. Abundant dikes and sills and the bathyal mudstone interbeds suggest that the coastal pillow basalts extruded locally onto the sea floor. Subaerial plateau-derived flows are associated with cross-bedded, fluvial to shallow marine arkosic sandstone interbeds. Some of these subaerial lavas flowed into the sea, forming "lava deltas" of foreset pillow palagonite and possibly "invasive" sills. The basalt stratigraphy allows a nearly flow by flow correlation of Grande Ronde and Frenchman Springs units from the Clackamas River area (Western Cascades) into this study area. The presence of Pomona Member in this area is the first substantiated recognition of this petrologically and chemically distinctive subaerial flow in northwestern Oregon. The 200-meter thick Clifton formation (previously called the Pliocene (?) sandstone at Clifton) is now dated by diatom assemblages and stratigraphic position as middle Miocene in age. Three lithofacies are recognized. Facies 1, at the base and top of the unit, is an arkosic, fine- to coarse- grained sandstone with cross-bedding, vertical Rosselia burrows, lignitic coal beds, and rare molluscan shells. It represents a river mouth and shallow marine offshore bar deposit. Facies 2, in the middle of the formation, consitst of well-laminated diatom-bearing carbonaceous and micaceous shelf/slope siltstones with thin fine-grained turbidite sandstones. Facies consists of channelized siltstone breccias, chaotic debris flows, thick amalgamated arkosic grain flows, structureless sandstones, and minor volcanic pebble conglomerates. These lithologies suggest a canyon head and slump deposit formed as a submarine channel cut into the shelf/slope siltstones of Facies 2. Sandstone petrography and grain size analyses indicate that the detritus of the Clifton and other sandstones in the area was derived from acid igneous, metamorphic, and intermediate volcanic provenances similar to those drained by the Columbia River today. Despite high measured permeabilities, breaching limits the reservoir potential of the sandstone. Mudstone units are immature to mature hydrocarbon source rocks. A potential for gas exists in the Cowlitz or its equivalent in the subsurface and in the Clifton channel sandstones projected into the offshore area. Title: The geology of the Nicolai Mountain-Gnat Creek area, Clatsop County, northwestern Oregon Author: Murphy, Thomas M. Twelve rock units, from upper Eocene to middle Miocene are exposed in the Nicolai Mountain-Gnat Creek area. They are, from oldest to youngest: Pittsburg Bluff Formation; Oswald West mudstone; Big Creek sandstone, upper Silver Point mudstone, and Pipeline mudstone members of the Astoria Formation; Depoe Bay Basalt; Grande Ronde Basalt; Cape Foulweather Basalt; and sandstone correlative to the Vantage Member of the Ellensburg Formation; Frenchman Springs Member of the Wanapum Basalt; Clifton, Formation (defined by author); and Pomona Member of the Saddle Mountains Basalt. Upper Eocene Pittsburg Bluff Formation is a fine-grained sandstone and laminated siltstone deposited in an inner to middle continental shelf environment. Concordant onlapping by the upper Oligocene, middle shelf to upper slope glauconitic Oswald West mudstone, establishes a tie between the northeastern and northwestern Oregon Coast Range stratigraphies. The lower to middle Miocene Astoria Formation represents another marine onlap sequence, beginning with the fine-grained cross-bedded inner shelf Big Creek sandstone member. The overlying laminted upper Silver Point and Pipeline mudstone members were deposited in a deepening middle shelf to upper slope environment. The middle Miocene tholeiitic basalts extruded from two sources. Grande Ronde, Frenchman Springs, and Pomona basalts of the Columbia River Group erupted from fissures east of the Cascades and flowed down an ancestral Columbia River valley entering the sea in the study area. Simultaneously, petrologically similar but less voluminous Depoe Bay and Cape Foulweather are correlative to the low MgO Grande Ronde and Frenchman Springs in the study area. Abundant dikes and sills and the bathyal mudstone interbeds suggest that the coastal pillow basalts extruded locally onto the sea floor. Subaerial plateau-derived flows are associated with cross-bedded, fluvial to shallow marine arkosic sandstone interbeds. Some of these subaerial lavas flowed into the sea, forming "lava deltas" of foreset pillow palagonite and possibly "invasive" sills. The basalt stratigraphy allows a nearly flow by flow correlation of Grande Ronde and Frenchman Springs units from the Clackamas River area (Western Cascades) into this study area. The presence of Pomona Member in this area is the first substantiated recognition of this petrologically and chemically distinctive subaerial flow in northwestern Oregon. The 200-meter thick Clifton formation (previously called the Pliocene (?) sandstone at Clifton) is now dated by diatom assemblages and stratigraphic position as middle Miocene in age. Three lithofacies are recognized. Facies 1, at the base and top of the unit, is an arkosic, fine- to coarse- grained sandstone with cross-bedding, vertical Rosselia burrows, lignitic coal beds, and rare molluscan shells. It represents a river mouth and shallow marine offshore bar deposit. Facies 2, in the middle of the formation, consitst of well-laminated diatom-bearing carbonaceous and micaceous shelf/slope siltstones with thin fine-grained turbidite sandstones. Facies consists of channelized siltstone breccias, chaotic debris flows, thick amalgamated arkosic grain flows, structureless sandstones, and minor volcanic pebble conglomerates. These lithologies suggest a canyon head and slump deposit formed as a submarine channel cut into the shelf/slope siltstones of Facies 2. Sandstone petrography and grain size analyses indicate that the detritus of the Clifton and other sandstones in the area was derived from acid igneous, metamorphic, and intermediate volcanic provenances similar to those drained by the Columbia River today. Despite high measured permeabilities, breaching limits the reservoir potential of the sandstone. Mudstone units are immature to mature hydrocarbon source rocks. A potential for gas exists in the Cowlitz or its equivalent in the subsurface and in the Clifton channel sandstones projected into the offshore area. Close