Search Results

No abstract available....

A three-dimensional finite-difference model of groundwater flow was used to estimate the hydraulic conductivity of riverbed and aquifer material in a 1-square-mile valley-fill aquifer system near a large river in which induced infiltration due to pumping cannot be measured directly. The aquifer consists of a 30- to 70-foot thickness of...

Major world resources of niobium and tantalum are described in this summary report of information in the International Strategic Minerals Inventory (ISMI). ISMI is a cooperative data-collection effort of earth-science and mineral-resource agencies in Australia, Canada, the Federal Republic of Germany, the Republic of South Africa, the United Kingdom, and...

Current activities of the Pennsylvania District of the USGS are described and include information on current projects, such as project objectives, approach, progress and plans, project location, cooperators, period of project, and project chief. Basic-data programs for surface water, ground water, and quality of water also are described. Also included...

Oxygen-isotope compositions of authigenic-layer silicates (<2-micrometer fraction) extracted from Mississippian and Pennsylvanian sandstones in the Lower Peninsula of Michigan were determined. Petrographic and scanning-electron-microscope examinations, and X-ray diffractograms show that chlorite and kaolinite are the most common authigenic-layer silicates in Mississippian sandstones. The range of oxygen-isotope compositions of chlorite and...

Bastnaesite, monazite, and xenotime are currently the most important rare-earth minerals. Bastnaesite occurs as a primary mineral in carbonatites. Monazite and xenotime also can be found in primary deposits but are recovered principally from heavy-mineral placers that are mined for titanium or tin. Each of these minerals has a different...

Ten low-flow hydrologic areas were defined for North Carolina by relating topography, geology, mean annual runoff, and other features to low-flow frequency characteristics for 122 continuous-record streamflow stations and 396 partial-record streamflow stations. Regression equations relating low-flow characteristics to mean annual discharge were developed for five of the hydrologic areas...

Data collected at 152 sampling sites during 1970-79 were used to characterize fluvial sediment in North Carolina streams. On the basis of predominant land use in individual basins, sites were categorized into one of five groups: forested (7 sites), forested and affected by minor development (7 sites), rural affected by...

Water samples from 167 wells and 12 surface-water sites at and near the Idaho National Engineering Laboratory were analyzed for a suite of as many as 23 trace elements in 1988-91. The samples were collected and analyzed as a continuation of a water-quality program initiated in 1987 and as part...

Volcanic eruptions are renowned for their violence and destructive power. This power comes ultimately from the heat and pressure of molten rock and its contained gases. Therefore we rarely consider the possibility that meteoric phenomena, like rainfall, could promote or inhibit their occurrence. Yet from time to time observers have...

No abstract available. ...

Sedimentary rocks of Late Cambrian through Early Cretaceous age in Kansas are part of a regional flow system of hydraulically connected aquifers and confining units. Future demands for water require that these deeply buried rocks be studied to describe hydrologic properties and ground-water-flow conditions and to provide information that will...

No abstract available....

GKS-PC is a Graphical Kernel System for the family of microcomputers compatible with the IBM-PC/MS-DOS standard. This library of functions allows an application program to control a computer graphics display conforming to a variety of graphics display standards.GKS-PC contains a subset of the GKS system of graphics primitive functions. GKS...

Selected basin characteristics and water-quality dam for the Minnesota River Basin are presented in this report as 71 maps, 22 graphs, and 8 tables. The data were compiled as part of a four-year study to identify non-point sources of pollution and the effect of this pollution on water quality. The...

No abstract available....