GIS Data

This geologic map of the Kings Mountain and Grover 7.5-min quadrangles, N.C.-S.C., straddles a regional geological boundary between the Inner Piedmont and Carolina terranes. The Kings Mountain sequence (informal name) on the western flank of the Carolina terrane in this area includes the Neoproterozoic Battleground and Blacksburg Formations. The Battleground Formation has a lower part consisting o

This historic trail map of the La Junta quadrangle contains all or part of eight Colorado and Kansas counties. Many of the historic trails in the La Junta quadrangle were used by Indians long before the white man reached the area. The earliest recorded use of the trails by white men in the quadrangle was in the 1820s when traders brought goods from St. Louis for barter with the Indians and for com

The Salinas alluvial fan area has historically been one of the most intensively used agricultural areas in the South Coastal Plain of Puerto Rico. Changes in agricultural practices and land use in the Salinas alluvial fan have also caused changes in the geographic distribution of ground-water withdrawals from the alluvial aquifer. As a result, the ground-water balance and ground-water flow pattern

This 1:100,000-scale digital geologic map details the complex Early Proterozoic granitic rocks, Early Proterozoic supracrustal metamorphic rocks, and Archean crystalline basement of the Black Hills. The granitic rocks host pegmatite deposits renowned for their feldspar, mica, spodumene, and beryl. The supracrustal rocks host the Homestake gold mine, which produced more than 40 million ounces of go

A ground-water level synoptic survey of the limestone aquifer in the Arecibo to Manati area, Puerto Rico, was conducted from November 27 through December 1, 2006 by the U.S. Geological Survey in cooperation with the Puerto Rico Department of Natural and Environmental Resources. The purpose of the study was to define the spatial distribution of the potentiometric surface of the upper and lower aqui

The Floridan aquifer system consists of the Upper and Lower Floridan aquifers separated by the middle confining unit. The middle confining unit and the Lower Floridan aquifer in west-central Florida generally contain highly mineralized water. The water-bearing units containing fresh water are herein referred to as the Upper Floridan aquifer. The Upper Floridan aquifer is the principal source of wa

The conodont color alteration index (CAI) introduced by Epstein and others (1977) and Harris and others (1978) is an important criterion for estimating the thermal maturity of Ordovician to Mississippian rocks in the Appalachian basin. Consequently, the CAI isograd maps of Harris and others (1978) are commonly used by geologists to characterize the thermal and burial history of the Appalachian bas

Warm Spring Canyon is located in the southeastern part of the Panamint Range in east-central California, 54 km south of Death Valley National Park headquarters at Furnace Creek Ranch. For the relatively small size of the area mapped (57 km2), an unusual variety of Proterozoic and Phanerozoic rocks is present. The outcrop distribution of these rocks largely resulted from movement on the east-west-s

The Tok area 1:100,000-scale map, through which the Alaska Highway runs, is in east-central Alaska about 160 km west of the Yukon border. The surficial geologic mapping in the map area is in support of the 'Geologic Mapping in support of land, resources, and hazards issues in Alaska' Project of the USGS National Cooperative Geologic Mapping Program. The Tok map area contains parts of three physiog

The Gold Creek, Nev. area displays important stratigraphic and structural relationships between Paleozoic and early Tertiary sedimentary strata in an area dominated by large intrusive bodies of Mesozoic age and extensive volcanic fields of middle to late Tertiary age. An autochthonous sequence includes the Cambrian and Proterozoic(?) Prospect Mountain Quartzite and the overlying Cambrian and Ordov

The nature and extent of valley-fill aquifers in the Port Jervis Trough was evaluated for a 16 mile section of this valley from the Orange-Sullivan County line near Westbrookville to the village of Napanoch in Ulster County as part of the U.S. Geological Survey's Detailed Aquifer Mapping Program in New York State. The principal aquifer in the Port Jervis Trough is a 50 feet thick outwash aquifer t

This map summarizes the geology of the Boxley 7.5-minute quadrangle in the Ozark Plateaus region of northern Arkansas. Geologically, the area lies on the southern flank of the Ozark dome, an uplift that exposes oldest rocks at its center in Missouri. Physiographically, the Boxley quadrangle lies within the Boston Mountains, a high plateau region underlain by Pennsylvanian sandstones and shales. Va