Geology topics
Research about Idaho
Source-linked reports with geographic coverage including Idaho.
Hydrology of subsurface waste disposal, National Reactor Testing Station, Idaho: Annual progress report for 1964
The principal purpose of the past research program on geohydrology at the NRTS has been to acquire information on the physical and geochemical environment of the station. This requires a knowledge of the composition and structure of the earth materials underlying the plain, the inventory of the water resources, the dynamics of natural and man-produced changes in the hydrologic regimen, details of the hydrologic cycle, and relevant geochemical processes. The Geological Survey in the course of its early studies by Nace and others (IDO 22033-34-USGS) obtained, compiled, and analyzed a considerable amount of basic geologic and hydrologic information on these subjects. These basic goals were expanded and carried forward to guide the continuing research work. Jones (IDO 22042-USGS) emphasized the use of borehole geophysics and specialized down-hole techniques. Olmsted (IDO 22043-USGS) made a preliminary appraisal of the nature and distribution of the quality of ground water beneath the Station. Their work has been continued and elaborated upon by Morris and others (IDO 22044-USGS, 46-USGS) and the present report with greater emphasis on the regional geology and hydrology. This involved some procurement of needed information but, for the most part, involved a continued evaluation and refinement of data and results that had been acquired in the past. The Geological Survey also encouraged a more comprehensive study of the regional geologic structure including the use of aeromagnetic, gravity, and seismic geophysical techniques and cosponsored a seminar on it in 1964. Along with this investigation and study of the regional geology and of hydrologic principles operative in the basalt environment, and made possible because of it, research continues on the-hydrologic aspects of the disposal of low-level aqueous waste to the environment.
Aeromagnetic map of part of the Lanes Creek quadrangle, Caribou County, Idaho
No abstract available.
Aeromagnetic map of the Pocatello-Soda Springs area, Bannock and Caribou Counties, Idaho
No abstract available.
Waterpower resources of Idaho
There are 46 developed waterpower projects having a total installed generating capacity of 1,472 megawatts (1 MW equals 1,000 kilowatts) in Idaho or on the State boundary line. When sites affecting two or more States are divided equally with the adjoining State, Idaho's allotment is 44 plants with an installed capacity of 1,025 megawatts. The gross theoretical capacity of the developed sites is 1,396 megawatts and of the undeveloped sites is 9,279 megawatts or a total of 10,675 megawatts. Power was computed for gross head, 100 percent efficiency, and average discharge. Grouped by magnitude of capability, there are 781 megawatts at 122 sites with individual capabilities of 1 to 4.99 megawatts, 2,744 megawatts at 120 sites with capabilities between 5 and 19.99 megawatts, and 7,150 megawatts at 63 sites with capabilities greater than 20 megawatts. The Snake River and its tributaries drain about 87 percent of Idaho's total area and contain 94 percent of its potential waterpower. The greatest areal concentration of waterpower, except for isolated reaches of the Snake River, is in the Clearwater River basin with about 264 kilowatts of theoretical potential per square mile. The gross theoretical power of the Salmon River basin, 3,326 MW, is the greatest of all Idaho rivers including the main stem of the Snake River. The first hydroelectric plant in Idaho was placed in operation in 1881. Waterpower has played an important part in the economy of Idaho since that time, and the State is in ninth place nationally in installed capacity of waterpower plants. Privately-owned plants produce 87.5 percent of the present average annual hydroelectric energy, and publicly-owned plants produce 12.5 percent. The principal producers are Idaho Power Company, Washington Water Power Company, Utah Power and Light Company, the Bureau of Reclamation, and the Corps of Army Engineers. The waterpower resources of Idaho are being actively developed at the present time and indications are that this active development rate will continue or accelerate.
Geology of the Coeur d'Alene district, Shoshone County, Idaho
The Coeur d'Alene district, near the base of the northern panhandle of Idaho, is one of the world's larger lead- zinc and silver-producing areas. The greater part of the dis~rict i~ included within five map areas, from east to west the Pottsville, Mullan, Wallace, Kellogg, and Smelterville, which were geologically mapped during this study. These quadrangles encompass an area about 26 miles long in an east-west direction and about 9 miles wide. The district lies wholly within the Coeur d'Alene Mountains, the part of the Bitterroot Range that is drained by the Coeur d'Alene River. The Bitterroot Range is a rugged, deeply dissected mountain mass which extends on both sides of the Idaho-Montana boundary for more than 200 miles and is a part of the Northern Rocky Mountains; within the district the range has a relief of 3,000-4,000 feet. The westward-flowing South Fork of the Coeur d'Alene River bisects the district, and roads along this river and its major tributaries generally provide easy access to the communities and many mines.
Geology of the Georgetown Canyon-Snowdrift Mountain area, southeastern Idaho
No abstract available.
Reconnaissance petrographic cross section of the Idaho batholith in Adams and Valley Counties, Idaho
No abstract available.
Natural gamma aeroradioactivity of the National Reactor Testing Station area, Idaho
No abstract available.
Review of waterpower withdrawals in Weiser River Basin, Idaho
The Weiser River basin is primarily agricultural and is supported by extensive irrigation. The Geological Survey has initiated withdrawals, or has made powersite classifications of lands having value for reservoir sites and for waterpower production. These withdrawals have been examined to see if they should continue in force or if it is in the public interest to restore them. The 1960 report, "Upper Snake River Basin," by the U.S. bureau of Reclamation, and U.S. Army Corps of Engineers included recommendations conooming potential water resource-development sites in Water River basin. That report furnished much of the information for this review.
Ground water for irrigation in the Snake River Basin in Idaho
The Snake River basin, in southern Idaho, upstream from the mouth of the Powder River in Oregon, includes more than 50 percent of the land area and 65 percent of the total population of the State. More than 2.5 million acres of land is irrigated ; irrigation agriculture and industry allied with agriculture are the basis of the economy of the basin. Most of the easily developed sources of surface water are fully utilized, and few storage sites remain where water could be made available to irrigate lands under present economic conditions. Because surface-water supplies have be come more difficult to obtain, use of ground water has increased greatly. At the present time (1959), about 600,000 acres of land is irrigated with ground water. Ground-water development has been concentrated in areas where large amounts of water are available beneath or adjacent to tracts of arable land and where the depth to water is not excessive under the current economy. Under these criteria, many of the most favorable areas already have been developed; however, tremendous volumes of water are still available for development. In some places, water occurs at depths considered near or beyond the limit for economic recovery, whereas in some other places, water is reasonably close to the surface but no arable land is available in the vicinity. In other parts of the basin large tracts of arable land are without available water supply. Thus the chief tasks in development of the ground-water resources include not only locating and evaluating ground-water supplies but also the planning necessary to bring the water to the land. Irrigation began in the 1860's ; at the present time more than 10 million acre feet of surface water, some of which is recirculated water, is diverted annually for irrigation of more than 2.5 million acres. Diversion of this large quantity of water has had a marked effect on the ground-water regimen. In some areas, the water table has risen more than 100 feet and the discharge of some springs has more than doubled. Large-scale development of ground water began after World War II, and it is estimated that in 1959 about 1,500,000 acre-feet of ground water was pumped for irrigation of the 600,000 acres irrigated wholly with ground water in addition to a substantial amount of ground water pumped to supplement surface-water supplies. Ground water is also the principal source of supply for municipal, industrial, and domestic use. The water regimen in the Snake River basin is greatly influenced by the geology. The rocks forming the mountains are largely consolidated rocks of low permeability; however, a fairly deep and porous subsoil has formed on them by decay and disintegration of the parent rock. Broad intermontane valleys and basins are partly filled with alluvial sand and gravel. The subsoil and alluvial materials are utilized very little as a source of water supply but are important as seasonal ground-water reservoirs because they store water during periods of high rainfall and snowmelt. Discharge from these reservoirs maintains stream flow during periods of surface runoff. Because these aquifers are fairly thin, they drain rapidly and are considerably depleted at the end of each dry cycle. The plain and plateau areas and tributary valleys, on the other hand, are underlain chiefly by rocks of high permeability and porosity. These rocks, mostly basaltic lava flows and alluvial materials, constitute a reservoir which fluctuates only slightly from season to season. Large amounts' of water are withdrawn from them for irrigation and other uses, and discharge from the Snake Plain aquifer is an important part of the total flow of the Snake River downstream from Hagerman Valley. The ultimate source of ground water in the basin is precipitation on the basin. In the mountainous areas, aquifers mostly are recharged directly by precipitation.
Overlapping of late mesozoic orogens in western Idaho
Early formed rocks of the border zone of the Idaho batholith are thrust westward over the low-grade metavolcanic rocks of the Seven Devils Mountains. Late intrusions of the border zone cut out upper plate rocks and contact-metamorphose lower plate rocks. Granitic intrusions in the Seven Devils complex are metamorphosed near the border zone of the Idaho batholith. Such relationships are interpreted in the light of a regional synthesis to indicate the overlapping and oblique truncation of the eastern part of a belt deformed largely during Jurassic time by the western part of a tectonic belt active during early stages of the middle Cretaceous events that produced the Idaho batholith.