USGS Science⌕ Search

SEARCH · USGS Science

Results for “Oregon Geology”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 397 records · Page 22Linked to original sources
USGS2007

Questions and Answers About the Effects of Septic Systems on Water Quality in the La Pine Area, Oregon

Nitrate levels in the ground-water aquifer underlying the central Oregon city of La Pine and the surrounding area are increasing due to contamination from residential septic systems. This contamination has public health implications because ground water is the sole source of drinking water for area residents. The U.S. Geological Survey, in cooperation with Deschutes County and the Oregon Department of Environmental Quality, studied the movement and chemistry of nitrate in the aquifer and developed computer models that can be used to predict future nitrate levels and to evaluate alternatives for protecting water quality. This fact sheet summarizes the results of that study in the form of questions and answers.

Fact Sheet↗
USGS1998

Major-ion, nutrient, and trace-element concentrations in the Steamboat Creek basin, Oregon, 1996

In September 1996, a water-quality study was done by the U.S. Geological Survey, in coordination with the U.S. Forest Service, in headwater streams of Steamboat Creek, a tributary to the North Umpqua River Basin in southwestern Oregon. Field measurements were made in and surface-water and bottom-sediment samples were collected from three tributaries of Steamboat Creek--Singe Creek, City Creek, and Horse Heaven Creek--and at one site in Steamboat Creek upstream from where the three tributaries flow into Steamboat Creek. Water samples collected in Singe Creek had larger concentrations of most major-ion constituents and smaller concentrations of most nutrient constituents than was observed in the other three creeks. City Creek, Horse Heaven Creek, and Steamboat Creek had primarily calcium bicarbonate water, whereas Singe Creek had primarily a calcium sulfate water; the calcium sulfate water detected in Singe Creek, along with the smallest observed alkalinity and pH values, suggests that Singe Creek may be receiving naturally occurring acidic water. Of the 18 trace elements analyzed in filtered water samples, only 6 were detected--aluminum, barium, cobalt, iron, manganese, and zinc. All six of the trace elements were detected in Singe Creek, at concentrations generally larger than those observed in the other three creeks. Of the detected trace elements, only iron and zinc have chronic toxicity criteria established by the U.S. Environmental Protection Agency (USEPA) for the protection of aquatic life; none exceeded the USEPA criterion. Bottom-sediment concentrations of antimony, arsenic, cadmium, copper, lead, mercury, zinc, and organic carbon were largest in City Creek. In City Creek and Horse Heaven Creek, concentrations for 11 constituents--antimony, arsenic, cadmium, copper, lead, manganese (Horse Heaven Creek only), mercury, selenium, silver, zinc, and organic carbon (City Creek only)--exceeded concentrations considered to be enriched in streams of the nearby Willamette River Basin, whereas in Steamboat Creek only two trace elements--antimony and nickel--exceeded Willamette River enriched concentrations. Bottom-sediment concentrations for six of these constituents in City Creek and Horse Heaven Creek--arsenic, cadmium, copper, lead, mercury, and zinc--also exceeded interim Canadian threshold effect level (TEL) concentrations established for the protection of aquatic life, whereas only four constituents between Singe Creek and Steamboat Creek--arsenic, chromium, copper (Singe Creek only), and nickel--exceeded the TEL concentrations.

Oregon↗
USGS1974

Some implications of late Cenozoic volcanism to geothermal potential in the High Lava Plains of south-central Oregon

Stratigraphic and volcanologic data obtained during reconnaissance mapping along the Brothers fault zone in the High Lava Plains of south-central Oregon (Walker and others, 1967; Greene and others, 1972) suggest a progressive decrease in age of eruption of silicic magmas from the Harney Basin westward to Newberry volcano and possibly beyond into the Cascade Range. South of the Brothers fault zone a separate, less well defined, parallel zone of silicic domes and flows extends westward from Beatys Butte; this zone also appears to show a decrease in age westward, although the time span apparently is shorter and the age decrease not as well documented. The apparent age progression and the obvious very young age and character of some of the silicic volcanic rocks at the western end of the zone is important in geologic evaluations of the geothermal potential of eastern Oregon. It suggests that igneous heat sources sufficiently young to have retained significant magmatic heat are most likely to occur at the western end of the zone. Geothermal energy associated with silicic volcanism is being explored or developed in several other parts of the world (White, 1965; Muffler and White, 1972; Grose, 1972). In areas of known geothermal potential, such as in New Zealand, Italy, Japan, and in North America at Yellowstone, the Jemez Mountains (N. Mex.), and probably the Geysers area of California, the age of silicic volcanism is very young, mostly less than a million years and commonly only a few tens or hundreds of thousands of years old, and the volume of silicic volcanism generally is large, in many places measured in terms of many cubic kilometers of magma. Because some domal masses at the west end of the Brothers fault zone are very young and some of the silicic volcanism along the zone was volumetrically large, the potential for magmatitic heat sources seems promising. To test the concept of an age progression in and along the Brothers fault zone, as determined from field geologic evidence, and to establish the absolute ages of some of the silicic volcanic rocks in and near this zone, several potassium argon ages have been determined on crystalline phases from rhyolitic, rhyodacitic, and dacitic domes and associated flows, on rhyolitic obsidian from chilled selvages on several domes and flows, and on crystals and glass from basal vitrophyre of small and large volume ash-flow tuffs erupted from centers spatially and probably genetically related to the Brothers fault zone.

Oregon↗
USGS2008

Environmental settings of selected streams sampled for mercury in Oregon, Wisconsin, and Florida, 2002-06

From 2002 through 2006, the U.S. Geological Survey National Water-Quality Assessment Program conducted studies investigating mercury biogeochemistry and food-web bioaccumulation in eight streams from three distinct geographic areas of the United States. These streams varied greatly in environmental characteristics, including land-cover, hydrologic, climatic, and chemical characteristics. They ranged from a clear-water, high-gradient, low-percentage wetland stream in the Cascade Mountains of Oregon, to an urban stream near Milwaukee, Wisconsin, to a low-gradient, blackwater stream draining the Okefenokee and Pinhook Swamps along the Georgia-Florida border. This report summarizes the environmental settings of these eight streams.

Florida, Oregon, Wisconsin↗
USGS2020

Black oystercatcher (Haematopus bachmani) population size, use of marine reserve complexes, and spatial distribution in Oregon

The Black Oystercatcher is a large shorebird found along the west coast of North America. Because of their small global population size, low reproductive rate, and dependence on rocky intertidal habitats, they are considered a “species of high conservation concern” and may act as an indicator of intertidal ecosystem health. In 2015, the Audubon Society of Portland initiated a 3-year shore-based population survey in Oregon building upon long-term monitoring previously conducted by the U.S. Geological Survey (USGS) and others. The objectives were to 1) Estimate the current minimum population of breeding Black Oystercatchers in Oregon and to compare that to previous estimates to better understand the population trend; 2) Document oystercatcher abundance adjacent to the Oregon’s system of Marine Reserves and Marine Protected Areas; and 3) Describe spatial distribution of breeding oystercatchers along the coast. We targeted all rocky shoreline habitats along Oregon’s coastline to perform abundance surveys each spring. A total of 75 survey routes were sampled using a standardized protocol. Trained volunteer community scientists conducted the majority of the surveys. We used N-mixture statistical models to estimate oystercatcher population size and probability of detection. Population estimates from the best fitting models were consistent, with estimates ranging from 506 oystercatchers in 2016 (95% credible interval, 463-560) to 629 (548-743) in 2015. These estimates indicated a small but stable population. Probability of detection remained consistent across years (ranging from 0.51 to 0.53). The effect of geographic region corresponded with greater bird density in the southern region of Oregon. Oystercatcher abundance adjacent to MR/MPAs accounted for between 12.4-18.3% of the total population estimate which was lower than expected (~25%). We recommend that subsequent conservation efforts directed on Black Oystercatchers in Oregon balance limiting human disturbance, particularly on the north and central coasts, with ensuring protection of core habitats on the south coast where much of the population resides.

Oregon↗
USGS1979

Water resources data for Oregon, water year 1978

Water resources Data for the 1978 water year for Oregon consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; and water levels and water quality in wells and springs. This report contains discharge records for 278 gaging stations; stage only records for 10 gaging stations; stage and contents for 44 lakes and reservoirs; water quality for 85 gaging stations, and water levels for 95 observation wells. Also included are 91 crest-stage partial-record stations. Additional water data were collected at various sites, not part of the systematic data collection program, and are published as miscellaneous measurements. These data represent that part of the National Water Data System operated by the U.S. Geological Survey and co-operating State and Federal agencies in Oregon.

Oregon↗
USGS2014

Geologic and physiographic controls on bed-material yield, transport, and channel morphology for alluvial and bedrock rivers, western Oregon

The rivers of western Oregon have diverse forms and characteristics, with channel substrates ranging from continuous alluvial gravel to bare bedrock. Analysis of several measurable morphologic attributes of 24 valley reaches on 17 rivers provides a basis for comparing nonalluvial and alluvial channels. Key differences are that alluvial reaches have greater bar area, greater migration rates, and show systematic correlation among variables relating grain size to bed-material transport capacity. We relate these differences between channel types to bed-material transport rates as derived from a coupled regional analysis of empirical sediment yield measurements and physical experiments of clast attrition during transport. This sediment supply analysis shows that overall bed-material transport rates for western Oregon are chiefly controlled by (1) lithology and basin slope, which are the key factors for bed-material supply into the stream network, and (2) lithologic control of bed-material attrition from in-transport abrasion and disintegration. This bed-material comminution strongly affects bed-material transport in the study area, reducing transport rates by 50%–90% along the length of the larger rivers in the study area. A comparison of the bed-material transport estimates with the morphologic analyses shows that alluvial gravel-bed channels have systematic and bounding relations between bed-material transport rate and attributes such as bar area and local transport capacity. By contrast, few such relations are evident for nonalluvial rivers with bedrock or mixed-bed substrates, which are apparently more influenced by local controls on channel geometry and sediment supply. At the scale of western Oregon, the physiographic and lithologic controls on the balance between bed-material supply and transport capacity exert far-reaching influence on the distribution of alluvial and nonalluvial channels and their consequently distinctive morphologies and behaviors—differences germane for understanding river response to tectonics and environmental perturbations, as well as for implementing effective restoration and monitoring strategies.

California, Nevada, Oregon, Washington↗
USGS1982

Reconnaissance geologic map and mineral resource potential of the Gearhart Mountain Wilderness and Roadless Area (6225), Lake and Klamath counties, Oregon

The Gearhart Mountain Wilderness, Lake and Klamath Counties, Oreg., is devoid of mines and mineral prospects and there are no known mining claims within the area. Furthermore, the results of this mineral appraisal indicate that there is little likelihood that commercial deposits of metallic minerals will be found in the area. Commercial uranium deposits, like those at the White King and Lucky Lass mines about 16 mi (~25 km) to the southeast of the wilderness, and deposits of mercury, like those south-southeast of the wilderness, are not likely to be found within the wilderness, even though all of these areas are characterized by middle and late Cenozoic intrusive and extrusive volcanic rocks. Rock of low commercial value for construction purposes is present, but better and more accessible deposits are present in adjacent regions. There is no evidence to indicate that mineral fuels are present in the area. Higher than normal heat floe characterizes the region containing Gerheart Mountain, indicating that it may have some, as yet undefined, potential for the development of geothermal energy. Data are not available to determine whether this higher than normal heat flow is meaningful in terms of a potential energy source or as a guide to possible future exploration; lack of thermal springs or other evidence of localized geothermal anomalies within the Gerhart Mountain suggest, however, that the potential for the development of geothermal energy is probably low.

Oregon↗
USGS2007

GIS data for the Seaside, Oregon, Tsunami Pilot Study to modernize FEMA flood hazard maps

A Tsunami Pilot Study was conducted for the area surrounding the coastal town of Seaside, Oregon, as part of the Federal Emergency Management's (FEMA) Flood Insurance Rate Map Modernization Program (Tsunami Pilot Study Working Group, 2006). The Cascadia subduction zone extends from Cape Mendocino, California, to Vancouver Island, Canada. The Seaside area was chosen because it is typical of many coastal communities subject to tsunamis generated by far- and near-field (Cascadia) earthquakes. Two goals of the pilot study were to develop probabilistic 100-year and 500-year tsunami inundation maps using Probabilistic Tsunami Hazard Analysis (PTHA) and to provide recommendations for improving tsunami hazard assessment guidelines for FEMA and state and local agencies. The study was an interagency effort by the National Oceanic and Atmospheric Administration, U.S. Geological Survey, and FEMA, in collaboration with the University of Southern California, Middle East Technical University, Portland State University, Horning Geoscience, Northwest Hydraulics Consultants, and the Oregon Department of Geological and Mineral Industries. The pilot study model data and results are published separately as a geographic information systems (GIS) data report (Wong and others, 2006). The flood maps and GIS data are briefly described here.

Oregon↗
USGS1999

Summary of the Columbia Plateau Regional Aquifer-System Analysis, Washington, Oregon, and Idaho

This report summarizes the results of the U.S. Geological Survey's Regional Aquifer-System Analysis program study of the Columbia Plateau aquifer system. The report describes the geologic framework, hydraulic characteristics of rock materials that compose the aquifer system, ground-water movement in the aquifer units, estimates of ground-water recharge, estimates of ground-water pumpage, and effects of surface-water irrigation and ground-water pumpage. The construction and use of a numerical ground-water flow model is described. Based on model results, the effects of potential water-development practices are presented. The ground-water quality and geochemistry of the aquifer system is then discussed.

Idaho, Oregon, Washington↗
USGS2006

Seaside, Oregon tsunami pilot study— Modernization of FEMA flood hazard maps

FEMA Flood Insurance Rate Map (FIRM) guidelines do not currently exist for conducting and incorporating tsunami hazard assessments that reflect the substantial advances in tsunami research achieved in the last two decades; this conclusion is the result of two FEMA-sponsored workshops and the associated Tsunami Focused Study. Therefore, as part of FEMA's Map Modernization Program, a Tsunami Pilot Study was carried out in the Seaside/Gearhart, Oregon, area to develop an improved Probabilistic Tsunami Hazard Assessment (PTHA) methodology and to provide recommendations for improved tsunami hazard assessment guidelines. The Seaside area was chosen because it is typical of many coastal communities in the section of the Pacific Coast from Cape Mendocino to the Strait of Juan de Fuca, and because State Agencies and local stakeholders expressed considerable interest in mapping the tsunami threat to this area. The study was an interagency effort by FEMA, U.S. Geological Survey and the National Oceanic and Atmospheric Administration, in collaboration with the University of Southern California, Middle East Technical University. Portland State University, Horning Geosciences, Northwest Hydraulics Consultants, and the Oregon Department of Geological and Mineral Industries. Draft copies and a briefing on the contents, results and recommendations of this document were provided to FEMA officials before final publication.

Oregon↗
USGS2006

Seaside, Oregon, Tsunami Pilot Study— Modernization of FEMA flood hazard maps: GIS data

Introduction: The Federal Emergency Management Agency (FEMA) Federal Insurance Rate Map (FIRM) guidelines do not currently exist for conducting and incorporating tsunami hazard assessments that reflect the substantial advances in tsunami research achieved in the last two decades; this conclusion is the result of two FEMA-sponsored workshops and the associated Tsunami Focused Study (Chowdhury and others, 2005). Therefore, as part of FEMA's Map Modernization Program, a Tsunami Pilot Study was carried out in the Seaside/Gearhart, Oregon, area to develop an improved Probabilistic Tsunami Hazard Analysis (PTHA) methodology and to provide recommendations for improved tsunami hazard assessment guidelines (Tsunami Pilot Study Working Group, 2006). The Seaside area was chosen because it is typical of many coastal communities in the section of the Pacific Coast from Cape Mendocino to the Strait of Juan de Fuca, and because State agencies and local stakeholders expressed considerable interest in mapping the tsunami threat to this area. The study was an interagency effort by FEMA, U.S. Geological Survey, and the National Oceanic and Atmospheric Administration (NOAA), in collaboration with the University of Southern California, Middle East Technical University, Portland State University, Horning Geoscience, Northwest Hydraulics Consultants, and the Oregon Department of Geological and Mineral Industries. We present the spatial (geographic information system, GIS) data from the pilot study in standard GIS formats and provide files for visualization in Google Earth, a global map viewer.

Oregon↗