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Research about Idaho

Source-linked reports with geographic coverage including Idaho.

At least 739 records · Page 41Linked to original sources
USGS1986

Role of replacement in the genesis of anorthosite in the Boehls Butte area, Idaho

In the Boehls Butte area, Idaho, three large and numerous small lenses of layered to massive anorthosite consisting of two, and locally three, types of plagioclase and minor hornblende and micas occur in aluminum silicate-rich garnet mica schist. In most of this anorthosite, andesine megacrysts with bytownite inclusions are embedded in a fine-grained groundmass of bytownite or anorthite. In places labradorite occurs instead of andesine. Some labradorite laths show Carlsbad twinning and rims of andesine around anorthite inclusions. Along the contacts, lenses of fine-grained bytownite anorthosite with some hornblende or garnet and quartz are common. These lenses could represent calcic parent rocks that were changed to two-plagioclase rocks by partial replacement of bytownite by andesine.

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USGS1986

Seismicity map of the state of Idaho

This map is one of a series of seismicity maps produced by the U.S. Geological Survey that show earthquake data of individual states or groups of states at the scale of 1:1,000,000. This map shows only those earthquakes with epicenters located within the boundaries of Idaho, even though earthquakes in nearby states or countries may have been felt or may have caused damage in Idaho. The USGS and the Idaho Geological Survey are continuing to research historical data with the objective of improving the pre-instrumental data listed below. The data in table 1 were used to compile the seismicity map; these data are a corrected, expanded, and updated (through 1983) version of the data used by Algermissen (1969) for a study of seismic risk in the United States. The locations and intensities of some earthquakes were revised and intensities were assigned where none had been before. Many earthquakes were added to the original list from new data sources as well as from some old data sources that had not been previously used. The data in table 1 represent earthquake on the basis of historical and current information. Some of the aftershocks from large earthquake are listed, but not all, especially for earthquakes that occurred before seismic instruments were universally used.

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USGS1986

Compilation of well and ground-water quality data, Groveland-Collins and surrounding areas near Blackfoot, Bingham County, Idaho

Well-construction, geologic, and water level data from 1978 to 1985 were compiled for 163 sites near Blackfoot, Idaho. Groundwater quality data were compiled for 51 sites for the period 1961-83 and for 54 sites for the period 1984-85. Data were collected in support of the hydrologic and water quality components of the U.S. Geological Survey 's groundwater contamination investigation near Blackfoot. Result of the investigation are presented in an interpretive report, published separately.

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USGS1986

Water resources data for Idaho, water year 1985

Water resources data for the 1985 water year for Idaho 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 of ground water. This report contains discharge records for 211 gaging stations; stage only records for 2 gaging stations; stage only for 8 lakes and reservoirs; contents only for 21 lakes and reservoirs; water quality for 19 gaging stations and 85 wells; and water levels for 415 observation wells. Additional water data were collected at various sites, not involved in 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 cooperating State and Federal agencies in Idaho, adjacent States, and Canada.

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USGS1986

Quality of ground water in the Payette River basin, Idaho

As part of a study to obtain groundwater quality data in areas of Idaho were land- and water-resource development is expected to increase, water quality, geologic, and hydrologic data were collected for 74 wells in the Payette River basin, west-central Idaho, from July to October 1982. Historical (pre-1982) data from 13 wells were compiled with more recent (1982) data to define, on a reconnaissance level, water quality conditions in major aquifers and to identify factors that may have affected groundwater quality. Water from the major aquifers generally contains predominantly calcium, magnesium, and bicarbonate plus carbonate ions. Sodium and bicarbonate or sulfate are the predominant ions in groundwater from 25% of the 1982 samples. Areally, groundwater from the upper Payette River basin has proportionately lower ion concentrations than water from the lower Payette River basin. Water samples from wells < 100 ft deep generally have lower ion concentrations than samples from wells > 100 ft deep. Variations in groundwater quality probably are most affected by differences in aquifer composition and proximity to source(s) of recharge. Groundwater in the study area is generally suitable for most uses. In localized areas, pH and concentrations of hardness, alkalinity, dissolved solids, or dissolved nitrite plus nitrate as nitrogen, sulfate, fluoride, iron, or manganese exceed Federal drinking water limits and may restrict some uses of the water.

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USGS1986

Hydraulic properties of rock units and chemical quality of water for INEL-1 — A 10,365-foot deep test hole drilled at the Idaho National Engineering Laboratory, Idaho

A 10,365-ft deep test hole drilled at the INEL (Idaho National Engineering Laboratory) in southeastern Idaho provided hydraulic information for rock units underlying the Snake River Plain aquifer. Four aquifer tests showed that the hydraulic conductivity decreased with depth--from an average of 0.03 ft/day for the interval from 1,511 to 2,206 ft below land surface to an average of 0.002 ft/day for the interval from 4 ,210 to 10,365 ft. In contrast the hydraulic conductivity of the Snake River Plain aquifer ranges from 1 to 100 ft/day. The hydraulic head increased with depth; the head at depth was about 115 ft greater than that for the Snake River Plain aquifer. Water temperature in the test hole increased from 26 C at 600 ft below land surface to 146 C at 9,985 ft. The gradient was nearly linear and averaged about 1.3 C/100 ft of depth. Water from the Snake River Plain aquifer contained 381 mg/L of dissolved solids and had a calcium bicarbonate chemical composition. The dissolved solids concentration in underlying rock units ranged from 350 to 1,020 mg/L and the water had a sodium bicarbonate composition. Hydrologic data for the test hole suggest that the effective base of the Snake River Plain aquifer near the test hole is between 840 and 1,220 ft below land surface. The upward vertical movement of water into the Snake River Plain aquifer from underlying rock units could be on the order of 15,000 acre-ft/year at INEL. (Author 's abstract)

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USGS1986

An overview of environmental surveillance of waste management activities at the Idaho National Engineering Laboratory

The Idaho National Engineering Laboratory (INEL), in southeastern Idaho, is a principal center for nuclear energy development for the Department of Energy (DOE) and the U.S. Nuclear Navy. Fifty-two reactors have been built at the INEL, with 15 still operable. Extensive environmental surveillance is conducted at the INEL by DOE's Radiological Environmental Sciences Laboratory (RESL), and the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), EG&G Idaho, Inc., and Westinghouse Idaho Nuclear Company (WINCO). Surveillance of waste management facilities radiation is integrated with the overall INEL Site surveillance program. Air, warer, soil, biota, and environmental radiation are monitored or sampled routinely at INEL. Results to date indicate very small or no impacts from INEL on the surrounding environment. Environmental surveillance activities are currently underway to address key environmental issues at the INEL.

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USGS1985

Characteristics of the aftershock sequence of the Borah Peak, Idaho, earthquake determined from digital recordings of the events

The U.S. Geological Survey, Menlo Park, deployed and maintained a network of twelve digital instruments over the 2 weeks following the 28 October 1983 Borah Peak, Idaho, earthquake. The network recorded 45 events with M ≧ 3.0, and 6 events with M ≦ 4.0. The epicenters are located in a narrow band which parallels the trace of the surface fauiting up to the Willow Creek summit; the depths of the events range from 5 to 16 km. In the south, the distribution of hypocenters delineate a plane which dips to the southwest at 50°; to the north, the hypocenters dip steeply to the east. Composite focal mechanisms for three groups of events show normal faulting mechanisms; the mechanism of the aftershocks in the north appear rotated in both strike and dip from the aftershocks in the south. The seismic moments of the aftershocks increase with increasing hypocentral depth below 12 km. The dynamic stress drops of the events do not show any systematic variation with depth, however. Most of the events with large stress drops are clustered in the northwest limb of the aftershock distribution; the average stress drop of the southern events is 31 ± 16 bars, while the average stress drop of the events in the northwest limb is 77 ± 52 bars. This clustering of events with large stress drops marks an apparent stress concentration, possibly associated with the arrest of the main shock rupture propagation by a fracture barrier at depth.

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USGS1985

Quaternary tectonic setting of the 1983 Borah Peak earthquake, central Idaho

The 1983 Borah Peak earthquake was accompanied by extensive surface faulting along a part of the Lost River fault that has abundant evidence of latest Quaternary (last 15,000 yr) offset. This fault and two similar range-front normal faults along the Lemhi Range and Beaverhead Mountains lie in an area of basin-and-range structure in central Idaho that is part of a roughly V-shaped belt of latest Quaternary surface faulting that extends from the Wasatch fault, through the Yellowstone area, to the Lost River fault. The position of this belt may be related to the outward migration of a thermal front associated with the northeastward progression of late Cenozoic silicic volcanism along the Yellowstone-Snake River Plain axis. The central segments of the Lost River, Lemhi, and Beaverhead faults have been active more recently, and probably more active throughout Quaternary time, than the southern and northern segments. The main 1983 surface faulting occurred in an area of high structural relief along a central segment of the Lost River fault that has ruptured in latest Quaternary time, which suggests that comparable areas along other range fronts in the area should be regarded as likely sites of future surface faulting. Other perspective of fault behavior suggest additional possible sites, and all segments of the range-front faults are regarded as capable of surface faulting.

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USGS1985

Maps showing selected geology and phosphate resources of the Harrington Peak quadrangle, Bear Lake and Caribou Counties, Idaho

This report summarizes information on the thickness, grade, lateral continuity, phosphate resources, and ownership of phosphate-bearing units in the Meade Park Phosphatic Shale Member of the Phosphoria Formation in the Harrington Peak quadrangle. This report is one of a series of quadrangle reports prepared by the Idaho Bureau of Mines and Geology under U.S. Geological Survey cost-sharing contract #14-08-0001-17925 to calculate phosphate resources in southeastern Idaho (fig. 1).

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