All Maps

The Bedrock Geologic Map of Vermont is the result of a cooperative agreement between the U.S. Geological Survey (USGS) and the State of Vermont. The State's complex geology spans 1.4 billion years of Earth's history. The new map comes 50 years after the most recent map of the State by Charles G. Doll and others in 1961 and a full 150 years since the publication of the first geologic map...

Io, discovered by Galileo Galilei on January 7–13, 1610, is the innermost of the four Galilean satellites of the planet Jupiter (Galilei, 1610). It is the most volcanically active object in the Solar System, as recognized by observations from six National Aeronautics and Space Administration (NASA) spacecraft: Voyager 1 (March 1979), Voyager 2 (July 1979), Hubble Space Telescope (1990...

No abstract available.

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 freshwater are herein referred to as the Upper Floridan aquifer. The Upper Floridan aquifer is the principal...

The Gates of the Arctic National Park and Preserve (GAAR) is centered over the central Brooks Range of northern Alaska. To the west, it abuts the Noatak National Preserve; its eastern boundary is the transportation corridor occupied by the Dalton Highway and the Alyeska Pipeline. The GAAR extends northward beyond the northern flank of the Brooks Range into the southern Arctic Foothills...

Most of the subsidence in the Houston-Galveston region has occurred as a direct result of groundwater withdrawals for municipal supply, industrial use, and irrigation that depressured and dewatered the Chicot and Evangeline aquifers causing compaction of the clay layers of the aquifer sediments. This report, prepared by the U.S. Geological Survey, in cooperation with the Harris-Galveston

New geologic mapping within the Sand Creek Pass 7.5 minute quadrangle defines geologic relationships within the northern Front Range of Colorado along the Wyoming border approximately 35 km south of Laramie, Wyo. Previous mapping within the quadrangle was limited to regional reconnaissance mapping; Eaton Reservoir 7.5 minute quadrangle to the east (2008), granite of the Rawah batholith...

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...

This map summarizes the geology of the Maumee 7.5-minute quadrangle in northern Arkansas. The map area is in the Ozark plateaus region on the southern flank of the Ozark dome. The Springfield Plateau, composed of Mississippian cherty limestone, overlies the Salem Plateau, composed of Ordovician carbonate and clastic rocks, with areas of Silurian rocks in between. Erosion related to the...

Digital flood-inundation maps for a 15-mile reach of the Kalamazoo River from Marshall to Battle Creek, Michigan, were created by the U.S. Geological Survey (USGS) in cooperation with the U.S. Environmental Protection Agency to help guide remediation efforts following a crude-oil spill on July 25, 2010. The spill happened on Talmadge Creek, a tributary of the Kalamazoo River near...

The geologic map of the Fraser quadrangle, Grand County, Colo., portrays the geology along the western boundary of the Front Range and the eastern part of the Fraser basin near the towns of Fraser and Winter Park. The oldest rocks in the quadrangle include gneiss, schist, and plutonic rocks of Paleoproterozoic age that are intruded by younger plutonic rocks of Mesoproterozoic age. These...

The bedrock geology of the Montpelier and Barre West quadrangles consists of Silurian and Devonian metasedimentary rocks of the Connecticut Valley-Gaspe synclinorium (CVGS) and metasedimentary, metavolcanic, and metaintrusive rocks of the Cambrian and Ordovician Moretown and Cram Hill Formations. Devonian granite dikes occur throughout the two quadrangles but are more abundant in the...