Publications

In order to determine whether it is desirable to quantify mineral-deposit models further, a test of the ability of a probabilistic neural network to classify deposits into types based on mineralogy was conducted. Presence or absence of ore and alteration mineralogy in well-typed deposits were used to train the network. To reduce the number of minerals considered, the analyzed data were...

Base- and precious-metal deposits in the central Wasatch Mountains southeast of Salt Lake City were mined for more than 100 years beginning in 1868. Deposits present in the Park City, Little Cottonwood, and Big Cottonwood mining districts include Ag-Pb-Zn ± Cu ± Au replacements and veins, a low-grade porphyry Cu-Au deposit, Cu-bearing skarns, a quartz monzonite-type (low F) porphyry Mo...

Today's field trip examines late Eocene and Oligocene granitoid intrusions, cogenetic volcanic rocks (Keetley Volcanics), and associated hydrothermally altered and mineralized rocks in the central Wasatch Mountains. Because of late Cenozoic tilting related to Basin and Range extension, a continuum of mid-Tertiary paleodepths is exposed that ranges from about 11 km on the west side of the...

Tephra layers in the ~323-m-deep Owens lake drill hole OL-92 correlate to tephra layers that have been identified and dated elsewhere in the western United States. Tephra layers identified are the Bishop ash bed (758 ka) at 309.2–298.6 m; the Dibekulewe (ash) bed (ca. 470 ka to ca. 610 ka) at ~224 m; and one of several ash beds in Walker Lake (ca. 60 ka to ca. 80 ka) at ~50.7 m. Other...

Surface and ground waters of the Central Valley of California (e.g., rivers, dams, off-stream storage reservoirs, pumping facilities, irrigation and drinking water supply canals, agricultural drainage canals) are part of a hydrologic system that makes up a complex ecosystem extending from the riparian wetlands of the Sacramento and San Joaquin Rivers through the San Francisco Bay/Delta...

Mining of mineral deposits in the Rocky Mountains has left a legacy of acidic inflows to otherwise pristine upland watersheds. Since 1986, the U.S. Geological Survey has studied physical, chemical, and biological processes that affect the transport and transformation of metals in St. Kevin Gulch, an acidic, metal-rich stream near Leadville, Colorado. Well-known chemical processes have...

No abstract available.

No abstract available.

This Open-File report is a digital geologic map database. This pamphlet serves to introduce and describe the digital data. There is no paper map included in the Open-File report. This digital map database is compiled from previously published sources combined with some new mapping and modifications in nomenclature. The geologic map database delineates map units that are identified by...

Introduction This digitally compiled map includes geology, geologic provinces, and oil and gas fields of Europe including Turkey. The maps are part of a worldwide series of maps on CD-ROM released by the U.S. Geological Survey's World Energy Project. The goal of the project is to assess the undiscovered, technically recoverable oil and gas resources of the world. For data management...

No abstract available.

The Little Piute Mountains Digital database contains digital geologic and geographic information for the study area. The geology was mapped at a scale of 1:8,000, and the topographic information was input from the Little Piute Mountains, CA 1:24,000 quadrangle. The accuracy of the spatial information is limited to the input scale. Postscript files, originally published in paper format as...