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Research about Idaho

Source-linked reports with geographic coverage including Idaho.

At least 667 records · Page 37Linked to original sources
USGS1991

Geologic map and profiles of the north wall of the Snake River Canyon, Thousand Springs and Niagara quadrangles, Idaho

The Snake River Plain is a broad, arcuate region of low relief that extends more than 300 mi across southern Idaho. The Snake River enters the plain near Idaho Falls and flows westward along the southern margin of the eastern Snake River Plain (fig. 1), a position mainly determined by the basaltic lava flows that erupted near the axis of the plain. The highly productive Snake River Plain aquifer north of the Snake River underlies most of the eastern plain. The aquifer is composed of basaltic rocks that are interbedded with fluvial and lacustrine sedimentary rocks. The top of the aquifer (water table) is typically less than 500 ft below the land surface but is deeper than 1,000 ft in a few areas. The Snake River has excavated a canyon into the nearly flat lying basaltic and sedimentary rocks of the eastern Snake River Plain aquifer, which discharges from the northern canyon wall as springs of variable size, spacing, and altitude. Geologic controls on springs are of importance because nearly 60 percent of the aquifer's discharge occurs as spring flow along the describes the geologic occurrence of springs along the northern wall of the Snake River canyon. This report is one of several that describes the geologic occurrence of springs along the northern wall of the Snake River canyon from Milner Dam to King Hill. To understand the local geologic controls on springs, the Water Resources Division of the U.S. Geological Survey initiated a geologic mapping project as part of their Snake River Plain Regional Aquifer System-Analysis Program. Objectives of the project were (1) to prepare a geologic map of a strip of land immediately north of the Snake River canyon, (2) to map the geology of the north canyon wall in profile, (3) to locate spring occurrences along the north side of the Snake River between Milner Sam and King Hill, and (4) to estimate spring discharge from the north wall of the canyon.

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USGS1991

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 data in table 1 were used to compile the seismicity map; these data are a corrected, expanded, and updated (through 1987) 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. The latitude and longitude coordinates of each epicenter were rounded to the nearest tenth of a degree and sorted so that all identical locations were grouped and counted. These locations are represented on the map by a triangle. The number of earthquakes at each location is shown on the map by the Arabic number to the right of the triangle. A Roman numeral to the left of a triangle is the maximum Modified Mercalli intensity (Wood and Neumann, 1931) of all earthquakes at that geographic location. The absence of an intensity value indicates that no intensities have been assigned to earthquakes at that location. The year shown below each triangle is the latest year for which the maximum intensity was recorded.

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USGS1991

Water resources data, Idaho, water year 1990

Water resources data for the 1990 water year for Idaho consist of records of stage, discharge, and water quality of streams; stage, contents, and water quality of lakes and reservoirs; discharge of irrigation diversions; and water levels and water quality of ground water. This report contains discharge records for 202 stream-gaging stations and 41 irrigation diversions; stage only records for 2 stream-gaging stations; stage only for 6 lakes and reservoirs; contents only for 21 lakes and reservoirs; water quality for 50 stream-gaging stations, 97 wells, and 1 lake; daily totals for 1 precipitation gage; and water levels for 473 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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USGS1991

Depth to water in the eastern Snake River Plain and surrounding tributary valleys, southwestern Idaho, calculated using water levels from 1980 to 1988

The vulnerability of ground water to contamination in Idaho is being assessed by the IDHW/DEQ (Idaho Department of Health and Welfare, Division of Environmental Quality), using a modified version of the Environmental Orotection Agency DRASTIC methods (Allers and others, 1985). The project was designed as a technique to: (1) Assign priorities for development of ground-water management and monitoring programs; (2) build support for, and public awareness of, vulnerability or ground water to contamination; (3) assist in the development of regulatory programs; and (4) provide access to technical data through the use of a GIS (geographic information system) (C. Grantha,, Idaho Department of Health and Welfare, written commun., 1989). A digital representation of first-encountered water below land surface is an important element in evaluating vulnerability of ground water to contamination. Depth-to-water values were developed using existing data and computer software to construct a GIS data set to be combined with a sols data set developed by the SCS (Soil Conservation Service) and IDHW/WQB (Idaho Department of Health and Welfare/Water Quality Bureau), and a recharge data set developed by the IDWR/RSF (Idaho Department of Water Resources/Remote Sensing Facility). The USGS (U.S. Geological Survey) developed digital depth-to-water values for eleven 1:100,000-scale quadrangles on the eastern Snake River Plain and surrounding tributary valleys.

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USGS1991

Depth to water in the western Snake River Plain and surrounding tributary valleys, southwestern Idaho and eastern Oregon, calculated using water levels from 1980 to 1988

The vulnerability of ground water to contamination in Idaho is being assessed by the ISHW/DEQ (Idaho Department of Health and Welfare, Division of Environmental Quality), using a modified version of the Environmental Protection Agency DRASTIC methods (Allers and others, 1985). The project was designed as a technique to: (1) Assign priorities for development of ground-water management and monitoring programs; (2) build support for, and public awareness of, vulnerability of ground water to contamination; (3) assist in the development of regulatory programs; and (4) provide access to technical data through the use of a GIS (geographic information system) (C. Grantham, Idaho Department of Health and Welfare, written commun., 1989). Digital representation of first-encountered water below land surface is an important element in evaluating vulnerability of ground water to contamination. Depth-to-water values were developed using existing data and computer software to construct a GIS data set to be combined with a soils data set developed by the SCS (Soul Conservation Service) and the IDHW/WQB (Idaho Department of Health and Welfare/Water Quality Bureau), and a recharge data set developed by the IDWR/RSF (idaho Department of Water Resources/Remote Sensing Facility). The USGS (U.S. Geological Survey) has developed digital depth-to-water values for eleven 1:100,00-scale quadrangles on the eastern Snake River Plain and surrounding tributary valleys.

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USGS1991

Surgical removal of a tracheal foreign body from a whooping crane (Grus americana)

The left wing of a whooping crane (Grus americana) was amputated for treatment of severe nonunion and malunion fractures of the radius and ulna. During the postoperative convalescent period, the bird aspirated a corn kernel and subsequently suffered episodic bouts of dyspnea. The bird was anesthetized with tiletamine-zolazepam. Attempts to deliver the kernel through the glottis with endoscopic instruments were unsuccessful. The corn kernel was retrieved via a tracheotomy incision. Endoscopy of the trachea 2 mo postoperatively showed complete healing of the tracheal incision. Mucosal integrity had been reestablished, and tracheal lumen diameter was not compromised. The bird continues in good health 2.5 yr after surgery, shows no sign of respiratory disease, and currently is in a captive breeding program.

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USGS1990

Chapter 21: Neodymium, strontium, and trace-element evidence of crustal anatexis and magma mixing in the Idaho batholith

Variations in initial 143 Nd/ 144 Nd in Late Cretaceous plutonic rocks along the South Fork of the Clearwater River (SFCR) supplement results of Sr and O studies, which demonstrate large-scale mixing in magmas forming the western margin of the Idaho batholith. These marginal or border phases of the batholith span the terrane boundary between Proterozoic crust of North America and late Paleozoic-Mesozoic intraoceanic arc terranes (WSD terranes), delineated by the Western Idaho suture zone (or WISZ). ɛ Nd (t) values in Early Cretaceous and older, pre-accretionary plutons of the WSD range from +3 to +7.6, and average +5.7. Proterozoic orthogneisses and metasedimentary rocks range from -7.4 to -13.7 and -10.45 to -15.7, respectively. ɛ Nd (t) in Late Cretaceous plutons of the SFCR decreases abruptly from west to east near the WISZ, varying inversely with ɛSr (t) . Although Sr isotopic evidence (Fleck and Criss, 1985) is consistent with a binary mixing model, Sm-Nd results modify those conclusions, suggesting that SFCR plutons may be divided into three groups. Group 1 plutons occur in a narrow zone (<4 km width) along the suture zone (WISZ). These bodies probably represent at least three-component mixtures of very high-Sr, arc-type magmas, one or more Proterozoic crustal components that may include lower crust, and a high-Nb, high-Zr component. Group 2 plutons are characterized by high ɛSr (t) .and nearly constant, low ɛNd (t) . These bodies are thought to represent mixtures of deep-seated partial melts of two different Proterozoic lithospheric types, possibly representing upper and lower crust. Plutons belonging to Group 3 have ɛNd (t) .values <-14 and probably incorporated substantial amounts of Proterozoic metasedimentary rocks, but mixing components are poorly defined. Trace-element variations in SFCR rocks also reflect the arc terrane-continental crustal boundary as Nb, Zr, and Nd increase dramatically, whereas Sr, Rb/Nb, and Sm/Nd exhibit coincident decreases east of the WISZ. Modeling of these variations with the isotopic variations in Nd and Sr supports mixing, but precludes contamination-bulk-assimilation models. Correlated ɛNd, ɛSr, and δ 18 O within the SFCR favors mixing of crustal and subcrustal magmas rather than derivation of the melts entirely from subcontinental lithosphere.

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USGS1990

Oxygen isotope map of the giant metamorphic-hydrothermal system around the northern part of the Idaho batholith, U.S.A.

Determinations of δ 18 O values from 100 outcrops of Belt Supergroup (Wallace Fm.) metasedimentary rocks in the Idaho panhandle reveal a regular regional pattern that was produced by pervasive fluid infiltration and isotopic exchange. Low grade argillites at large distances (60 km) from the Idaho batholith have high δ 18 O values +15, compatible with their probable primary values. Pelitic rocks with anomalously low δ 18 O values of + 8.7 to + 12.7‰ occur in the following zones: (1) in a 5000 km 2 zone of schist and gneiss peripheral to the Idaho batholith, generally coincident with high-grade (sillimanite-bearing) assemblages; (2) in high-grade metasedimentary roof pendants within the Idaho batholith; (3) peripheral to small Cretaceous stocks; and (4) within and near the scapolite-bearing zone south-west of St. Regis. On δ 18 O−δ 18 O plots, data from coexisting minerals define trends with unit slopes, indicating that the reductions in 18 O occurred under high-grade metamorphic conditions. This metamorphism culminated in the emplacement of the Idaho batholith, probably as a consequence of profound crustal thickening associated with the Cretaceous accretion of the Wallowa-Seven Devils arc terranes with North America. The huge low- 18 O region is bounded by a “steep” δ 18 O gradient (0.1–0.5‰/km) that occurs in low-grade rocks along and near the Lewis and Clark Line, well below the biotite isograd. This boundary zone may be analogous to, but is not nearly as sharp as, those of meteoric-hydrothermal systems in many regions. The important ore deposits of the Coeur d'Alene district are located in this peripheral zone, suggesting that the metamorphic-hydrothermal system may have been intimately involved in their formation. In addition, the metamorphic-hydrotermal system in Idaho is larger, deeper and higher in temperature than typical meteoric-hydrothermal systems, and it involved fluids with much higher δ 18 O values that were probably dominantly derived from formation waters. Accordingly, this system produced rocks with δ 18 O values similar to those of the Idaho batholith, and mineral assemblages that approach isotopic equilibrium under high temperature conditions.

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USGS1990

Geologic map and profiles of the north wall of the Snake River Canyon, Bliss, Hagerman, and Tuttle quadrangles, Idaho

The Snake River Plain is a broad, arcuate region of low relief that extends more than 300 mi across southern Idaho. The Snake River enters the plain near Idaho Falls and flows westward along the southern margin of the eastern Snake River Plain (fig. 1), a position mainly determined by the basaltic lava flows that erupted near the axis of the plain. The highly productive Snake River Plain aquifer north of the Snake River underlies most of the eastern plain. The aquifer is composed of basaltic rocks that are interbedded with fluvial and lacustrine sedimentary rocks. The top of the aquifer (water table) is typically less than 500 ft below the land surface, but is deeper than 1,000 ft in a few areas. The Snake River has excavated a canyon into the nearly flat-lying basaltic and sedimentary rocks of the eastern Snake River Plain between Milner Dam and King Hill (fig. 2), a distance of almost 90 mi. For much of its length the canyon wall as springs of variable size, spacing, and altitude. Geologic controls on springs are of importance because nearly 60 percent of the aquifer's discharge occurs as spring flow along this reach of the canyon. This report is one of several that describes the geologic occurrence of springs along the northern wall of the Snake River canyon from Milner Dam to King Hill (fig. 1). To understand the local geologic controls on springs, the Water Resources Division of the U.S. Geological Survey initiated a geologic mapping project as part of their Snake River Plain Regional Aquifer System-Analysis Program. Objectives of the project were (1) to prepare a geologic map of a strip of land immediately north of the Snake River canyon, (2) to map the geology of the north canyon wall in profile, (3) to locate spring occurrences along the north side of the Snake River between Milner Dam and King Hill, and (4) to estimate spring discharge from the north wall of the canyon.

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