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Geology topics

William H. Langer

Publications and source records attributed to William H. Langer.

At least 55 records · Page 3Linked to original sources
USGS1990

Reconnaissance study of the thickness of the unsaturated zone in the western conterminous United States

In 1984, the U.S. Geological Survey began a study of the geologic and hydrologic characteristics of the unsaturated zone in the western conterminous United States. The study area extends from the eastern edge of the Rocky Mountains westward and includes all or parts of the 12 westernmost conterminous States. The goal of the study is to characterize unsaturated flow systems to aid in identifying environments in the western United States that may merit further study for isolation of hazardous waste, including high- and low-level radioactive waste and other toxic waste. The major physiographic areas discussed in this report (see index map below thickness map) are: (1) Rocky Mountain System consisting of the Southern, Middle, and Northern Rocky Mountains, and the Wyoming Basin; (2) Intermontane Plateaus consisting of the Basin and Range province, and the Colorado and Columbia Plateaus; and (3) Pacific Mountain System (Fenneman, 1946). Two of these areas, the Colorado and Columbia plateaus, exhibit a variety of geohydrologic conditions, and therefore are further subdivided in the discussions that follow. Outstanding features peculiar to the mountainous area of the Rocky Mountain and the Pacific Mountain Systems are the high rugged mountains and steep relief. These mountains receive greater precipitation than do the lower parts of the otherwise dry western United States. Generally moisture-laden air masses move eastward across the continent, and the mountains force them to higher, cooler altitudes. As the air cools, moisture condenses and precipitates. As a result, the Rocky Mountain and Pacific Mountain Systems have annual precipitation in excess of 30 in. The Wyoming Basin of the Rocky Mountain System and the Basin and Range province, Colorado Plateaus, and Columbia Plateaus of the Intermontane Plateaus generally have lower altitudes and less relief than do the mountainous areas. The climate throughout most of these provinces generally is semiarid to arid. Annual precipitation is generally less than 16 in. throughout most of the area, and is less than 4 in. in some parts. The mean annual free-water-surface evaporation ranges from 20 to 100in. A large part of the study area is subject to a water deficit because potential evapotranspiration exceeds precipitation. As a consequence of the large water deficit, ground-water recharge generally is small, surface runoff is small, perennial streams and lakes are few, and the depth to ground water commonly is large. The generalized thickness of the unsaturated zone (the depth to ground water), in the western conterminous United States is presented on the map.

Hydrologic Atlas↗
USGS1989

Studies of geology and hydrology in the Basin and Range Province, Southwestern United States, for isolation of high-level radioactive waste - Basis of characterization and evaluation

The geologic and hydrologic factors in selected regions of the Basin and Range province were examined to identify prospective areas for further study that may provide isolation of high-level radioactive waste from the accessible environment. The six regions selected for study were characterized with respect to the following guidelines: (1) Potential repository media; (2) Quaternary tectonic conditions; (3) climatic change and geomorphic processes; (4) ground-water conditions; (5) ground-water quality; and (6) mineral and energy resources. The repository medium will function as the first natural barrier to radionuclide travel by virtue of associated slow ground-water velocity. The principal rock types considered as host media include granitic, intermediate, and mafic intrusive rocks; argillaceous rocks; salt and anhydrite; volcanic mudflow (laharic) breccias; some intrusive rhyolitic plugs and stocks; partially zeolitized tuff; and metamorphic rocks. In the unsaturated zone, the permeability and hydrologic properties of the rocks and the hydrologic setting are more important than the rock type. Media ideally should be permeable to provide drainage and should have a minimal water flux The ground-water flow path from a repository to the accessible environment needs to present major barriers to the transport of radionuclides. Factors considered in evaluating the ground-water conditions include ground-water traveltimes and quality, confining beds, and earth materials favorable for retardation of radionuclides. Ground-water velocities in the regions were calculated from estimated hydraulic properties of the rocks and gradients. Because site-specific data on hydraulic properties are not available, data from the literature were assembled and synthesized to obtain values for use in estimating ground-water velocities. Hydraulic conductivities for many rock types having granular and fracture permeability follow a log-normal distribution. Porosity for granular and very weathered crystalline rock tends to be normally distributed; porosity of fractured crystalline rock probably follows a log-normal distribution. The tectonic setting needs to prevent an increase in radionuclides to the accessible environment. Data on historic seismicity and heat flow, Quaternary faults, volcanism, and uplift were used to assess the tectonic conditions. Long-term late Cenozoic rates of vertical crustal movement in the Basin and Range province range from less than 2 meters per 104 years to greater than 20 meters per 104 years. Shortterm rates of vertical movement may be more than an order of magnitude greater, based on geodetic leveling. Changes in tectonic and climatic processes may potentially cause changes in hydrologic conditions and geomorphology that could affect the integrity of a deep, mined repository either adversely or beneficially. The transition from a full-glacial climate to the current interglacial condition has occurred within the past 15,000 years. Reconstructions of the last full-glacial climate indicate that, at that time, there was greater water availability for runoff and vegetation growth than there is now. Based on the increased water availability and depending on seasonal distribution of precipitation, on soil characteristics, on topography, and on other characteristics, ground-water recharge during the full-glacial climate is estimated to have been possibly 2 to 10 or more times the modern rate. During the full-glacial climate, more than 100 lakes occupied closed basins in the province. Any increase in ground-water recharge and refilling of Pleistocene lakes will tend to decrease the distance of ground-water flow and its time of travel. The unsaturated zone this zone is considered a potential host medium where the thickness is greater than 150 m will be decreased by these changes. In contrast, incision of streams and other geomorphic, tectonic, or climatically induced changes that lower the ground-water discharge level will tend to increase the thickness of the unsaturated zone. Aggradation in basinal troughs may either decrease or increase the thickness of the unsaturated zone. Aggradation in basins that causes the ground-water discharge level to rise will tend to decrease the thickness of unsaturated zone in the adjacent uplands; aggradation in basins where the ground-water discharge level remains the same or is lowered will increase the unsaturated thickness of basin fill. Records show that, throughout late Cenozoic time in the Basin and Range province, continued vertical crustal movements have tended to maintain mountain ranges and closed basins, whereas aggradation of the basins and erosion of the mountain ranges have tended to decrease the topographic relief. Maximum rates of denudation for small basins in areas climatically similar to the Basin and Range province are about 2 meters per 104 years. For sites unaffected by stream incision and scarp retreat, a conservative estimate of erosion affecting long-term changes in depth of burial would appear to be 2 meters per 104 years, or, equal to the long-term rate of vertical crustal movement where greater than 2 meters per 104 years. The response of the ground-water conditions to climatic and geomorphically induced boundary conditions is significant from the points of: (1) The potential maximum change in the ground-water flow system; (2) the time of response of the ground-water system; and (3) the present state of the ground-water system as a result of past changes. Effects of longterm climatic and tectonic changes on hydrologic and geomorphic conditions differ from area to area, and rates of change of geomorphic and hydrologic conditions may vary significantly. Therefore, sitespecific studies need to be made to assess the long-term integrity of deep, mined repositories.

Arizona, California, Idaho, Nevada, New Mexico, Te↗
USGS1988

Natural aggregates of the conterminous United States

Crushed stone and sand and gravel are the two main sources of natural aggregates. These materials are commonly used construction materials and frequently can be interchanged with one another. They are widely used throughout the United States, with every State except two producing crushed stone. Together they amount to about half the mining volume in the United States. Approximately 96 percent of sand and gravel and 77 percent of the crushed stone produced in the United States are used in the construction industry. Natural aggregates are widely distributed throughout the United States in a variety of geologic environments. Sand and gravel deposits commonly are the results of the weathering of bedrock and subsequent transportation and deposition of the material by water or ice (glaciers). As such, they commonly occur as river or stream deposits or in glaciated areas as glaciofluvial and other deposits. Crushed stone aggregates are derived from a wide variety of parent bedrock materials. Limestone and other carbonates account for approximately three quarters of the rocks used for crushed stone, with granite and other igneous rocks making up the bulk of the remainder. Limestone deposits are widespread throughout the Central and Eastern United States and are scattered in the West. Granites are widely distributed in the Eastern and Western United States, with few exposures in the Midwest. Igneous rocks (excluding granites) are largely concentrated in the Western United States and in a few isolated localities in the East. Even though natural aggregates are widely distributed throughout the United States, they are not universally available for consumptive use. Some areas are devoid of sand and gravel, and potential sources of crushed stone may be covered with sufficient unconsolidated material to make surface mining impractical. In some areas many aggregates do not meet the physical property requirements for certain uses, or they may contain mineral constituents that react adversely when used as concrete aggregate. In areas where suitable natural aggregate is not available or accessible, it may become necessary to improve the quality of existing aggregate, to import aggregate from outside the area, or to substitute artificial aggregate for natural aggregate. In most cases, all of these alternatives add substantially to the cost of the final product. Even though an area may be blessed with an abundance of aggregate suitable for the intended purpose, existing land uses, zoning, or regulations may preclude commercial exploitation of the aggregate. This report also discusses the aggregate industry in general terms, including exploration, mining, and processing, as well as aggregate production rates. Proper long-range planning based on an understanding of the aggregate industry can help assure adequate supplies of aggregate.

conterminous United States↗
USGS1984

Maps showing ground-water levels, springs, and depth to ground water, Basin and Range Province, Southern California

This report on ground-water levels, springs and depth to ground water in the Basin and Range province of southern California (see index map) was prepared as part of a program of the U.S. Geological Survey to identify prospective regions for further study relative to isolation of high-level nuclear waste (Bedinger, Sargent, and Reed, 1984), utilizing program guidelines defined in Sargent and Bedinger (1984). Also included in this report are selected references on pertinent geologic and hydrologic studies of the region. Other map reports in this series contain detailed data on ground-water quality, surface distribution of selected rock types, tectonic conditions, areal geophysics, Pleistocene lakes and marshes, and mineral and energy resources.

California↗
USGS1984

Maps showing ground-water levels, springs, and depth to water, Basin and Range Province, Nevada

This report on ground-water levels, springs and depth to ground water in the Basin and Range province of Nevada (see index map) was prepared as part of a program of the U.S. Geological Survey to identify prospective regions for further study relative to isolation of high-level nuclear waste (Bedinger, Sargent, and Reed, 1984), utilizing program guidelines defined in Sargent and Bedinger (1984). Also included in this report are selected references on pertinent geologic and hydrologic studies of the region. Other map reports in this series contain detailed data on ground-water quality, surface distribution of selected rock types, tectonic conditions, areal geophysics, Pleistocene lakes and marshes, and mineral and energy resources.

Nevada↗
USGS1984

Maps showing ground-water levels, springs, and depth to water, Basin and Range Province, Oregon

This report on ground-water levels, springs and depth to ground water in the Basin and Range province of Oregon (see index map) was prepared as part of a program of the U.S. Geological Survey to identify prospective regions for further study relative to isolation of high level nuclear waste (Bedinger, Sargent, and Reed, 1984), utilizing program guidelines defined in Sargent and Bedinger (1984). Also included in this report are selected references on pertinent geologic and hydrologic studies of the region. Other map reports in this series contain detailed data on ground-water quality, surface distribution of selected rock types, tectonic conditions, areal geophysics, Pleistocene lakes and marshes, and mineral and energy resources.

Oregon↗
USGS1978

Relationship of landslides to fractures in Potomac Group deposits, Fairfax County, Virginia

Landsliding is a common problem in eastern Fairfax County, an area underlain by Potomac Group (Lower Cretaceous) Coastal Plain deposits of silt and clay interbedded and interfingered with sand and gravel. The slides commonly are present in clay and silt that, on the basis of laboratory tests, appear to be much too strong to have failed. However, the very plastic silt and clay deposits are commonly cut by long continuous to short discontinuous high-angle and subhorizontal joints, shears, and faults. These fractures can contribute to sliding. Failure along faults and shears takes place because the relative movement has greatly weakened and softened the clay and silt. The mechanism for failure along the joints is less obvious but may be related to infilling along joints, slight movement due to erosional unloading, swelling of clays, and softening along joints. Field investigations suggest that the three best developed high-angle joint sets in eastern Fairfax County have trends in the northeast quadrant. Lineaments plotted on a lineament map prepared from Landsat imagery also trend northeast parallel to the regional joint orientation. This regional orientation suggests that some of the fractures are tectonic in origin. Therefore, they should be anticipated in a broad zone many miles wide in the vicinity of the Fall Line. In addition, fractures of unknown origin contributing to landsliding, have been observed in massive Potomac Group clay and silt deposits. Irrespective of origin, these fractures require careful investigation and engineering to prevent slope failure at critical locations during and after major excavation.

Virginia↗
USGS1977

Map showing texture of unconsolidated materials, Connecticut Valley urban area, central New England (north and south sheets)

This map shows the areal distribution of unconsolidated materials which are composed of loose rock particles deposited predominantly through the action of glacier ice and glacial meltwater. These materials vary greatly in thickness, mineral composition, and in particle-size distribution. Each map unit characterizes the mixture of particle-sizes (texture) in the unconsolidated material to a depth of at least 3 feet a meter) beneath the soil layer. The block diagram below shows the typical three-dimensional relationship between bedrock and unconsolidated materials in the Connecticut Valley Urban Area. Bedrock is overlain in Lost places by unconsolidated material; surface exposuresof bedrock occur throughout the map area, but mainly in the upland till areas; bedrock outcrops are not shown on this map.

Connecticut Valley, New England↗