Map Releases

No abstract available.

Significant quantities of recoverable natural gas resources are estimated to be in the regionally extensive Lower Silurian Medina Group and “Clinton” sandstone of the Appalachian Basin (Gautier and others, 1995; Ryder and others, 1996; Ryder, 1998). In order to assess these accumulations of natural gas more accurately, the U.S. Geological Survey (USGS) has investigated the Silurian stratigraphy al

On February 2 and 3, 1998, a rainstorm generated by the 1997-98 El Nino moved through the San Francisco Bay region of California triggering widespread slope failures. In the Walpert Ridge area of Alameda County 531 debris flows were triggered by the storm. These data depict the debris flows and landslides as polygons. The landslide polygons were mapped from 1:30,000 aerial photography using a PG2

This digital geologic map compilation presents new polygon (i.e., geologic map unit contacts), line (i.e., fault, fold axis, and structure contour), and point (i.e., structural attitude, contact elevations) vector data for the Jasper 7 1/2' quadrangle in northern Arkansas. The map database, which is at 1:24,000-scale resolution, provides geologic coverage of an area of current hydrogeologic, tect

New 1:24,000-scale geologic map of the Rifle Falls 7.5' quadrangle, in support of the USGS Western Colorado I-70 Corridor Cooperative Geologic Mapping Project, provides new interpretations of the stratigraphy, structure, and geologic hazards in the area of the southwest flank of the White River uplift. Bedrock strata include the Upper Cretaceous Iles Formation through Ordovician and Cambria

This map was prepared as a collaborative effort with the Missouri Division of Geology and Land Survey, the Kansas Geological Survey, and the Nebraska Conservation and Survey Division. Map units and preliminary contacts between units were identified using stereoscopic pairs of high altitude, false color infrared, aerial photographs. Contacts were drawn on twelve USGS 7.5-minute topographic maps, an

The bedrock exposed in the Winona Quadrangle, Missouri, comprises Mesoproterozoic aged volcanic rocks overlain by Late Cambrian and Early Ordovician aged dolomite, sandstone, and chert. The sedimentary rocks are nearly flat-lying except where they drape around knobs of the volcanic rocks or where they are adjacent to faults. The carbonates are karstified and the area contains numerous sinkholes,

This digital map database, compiled from previously published and unpublished data, and new mapping by the authors, represents the general distribution of bedrock and surficial deposits in the mapped area. Together with the accompanying text file (scvmf.ps, scvmf.pdf, scvmf.txt), it provides current information on the geologic structure and stratigraphy of the area covered. The database delineat

No abstract available.

No abstract available.

Map data that predict the varying likelihood of landsliding can help public agencies make informed decisions on land use and zoning. This map, prepared in a geographic information system from a statistical model, estimates the relative likelihood of local slopes to fail by two processes common to an area of diverse geology, terrain, and land use centered on metropolitan Oakland. The model com

No abstract available.