Nd and Pb isotopic analyses from stratigraphic sampling from Somma-Vesuvius volcanic complex, Italy, during the last 3550 years point to contributions from heterogeneous lithosphere, continental crust, and magma mixing.

Miocene calc-alkaline volcanic rocks, part of the southern segment of the ancestral Cascades magmatic arc, are spatially, temporally, and likely genetically associated with precious metal epithermal deposits in the Tonopah, Divide, and Goldfield Districts

40Ar/39Ar dating, electron microprobe analyses and geologic mapping help clarify chronology and correlations of the numerous volcanic and intrusive units exposed in the area and interpret the petrogenesis of a few of the volcanic units.

Whole rock geochemical data for volcanic rocks in this area, both extrusive rocks and hypabyssal dikes. Major oxides and trace elements are included. Data are provided in CSV format.

Presents data for mineral deposits and unaltered and hydrothermally altered volcanic rocks. Data presented were acquired in three USGS labs by three different geochronologists. Analytical methods and data derived from each lab are presented separately.

Data for 90 rock samples collected from 2001 to 2007 for geophysical, geochemical, mineralogical, and environmental rock properties of acid neutralizing capacity and net acid production.

Chemical analysis of altered volcanic rocks to determine their potential for neutralization of acid-rock drainage. Includes magnetic susceptibility measurements as well.

Regional maps of phyllic and argillic hydrothermal alteration are presented on 10 separate plates available in either low or high resolution. A GIS package includes points features for potential porphyry copper sites also provided in tabular form.

Geochemical analyses of rocks, mineral separates, bulk samples from lake and stream sediments, heavy mineral concentrates, and soils collected by USGS from 1962 to 2009.

Geochemical analysis of rock, sediment, soil, mineral, and heavy mineral concentrate samples in Alaska analyzed from 1938 through 2017. Includes best-value chemical element concentrations as well as mineralogical analysis. Data are provided in Microsoft Access and CSV formats.

The Alaska Geochemical Database Version 3.0 (AGDB3) contains new geochemical data compilations in which each geologic material sample has one “best value” determination for each analyzed species, greatly improving speed and efficiency of use. Like the

Geochemical analyses of rock, sediment, soil, mineral, and heavy mineral concentrate samples in Alaska analyzed from 1962 through 2009, with best-value estimates.

Geochemical analyses of rocks, mineral separates, bulk samples from lake and stream sediments, heavy mineral concentrates, and soils collected by USGS from 1962 to 2009.

Nevada is one of the Earth's premier gold producing regions, accounting for approximately 64 percent of the U.S and nine percent of the world total. The impact of these mines on nearby local economies and on our national balance of payments is profound, a

The Paleocene Fort Union Formation hosts a compositionally diverse array of Eocene plugs, dikes, and sills arrayed around the Eocene Big Timber stock in the Crazy Mountains of south-central Montana. The geochemistry and petrography of the sills have no

New age determinations with descriptions of sample locations and analytical details.

Mineralogical data on samples from the surface and from drill cores, with geological observations help to understand the hydrology and effects of geology on acid-rock drainage in a mineralized alpine watershed.

Spatial geologic map with rock type, vents, arcs, landslides, etc. provided in an ESRI geodatabase and KMZ format for Google Earth viewing. Mapsheet with accompanying descriptive pamphlet is provided as a PDF. Petrographic rock summary is also included.

This map, compiled from geologic mapping conducted (1985-1992) by the U.S. Geological Survey as part of the Alaska Mineral Resource Assessment Program, builds upon previous USGS work unraveling the magmatic history of the Alaska-Aleutian Range batholith.

Geochemical data from selected USGS projects from the 1960s-1980s that were previously not published as digital data. Includes geochemical analyses from 36,498 samples of various types using analytical methods and instruments that were current when those studies were carried out. Data are provided in Microsoft Access, shapefile, and CSV formats.

Geochemical analyses of silicate melt inclusions, host quartz phenocrysts, and biotite phenocrysts in samples of these rocks. Data are provided in CSV format.

Study delineated permissive areas for undiscovered porphyry copper deposits, compiled a database of known deposits and significant prospects, estimated undiscovered deposits within those areas and made probabilistic estimates of their metal content.

Delineated permissive areas for undiscovered porphyry copper deposits, compiled a database of known deposits and significant prospects, estimated undiscovered deposits within those areas and made probabilistic estimates of their metal content.

This study delineated permissive areas for undiscovered porphyry copper deposits, compiled a database of known deposits and significant prospects, estimated undiscovered deposits within those areas and made probabilistic estimates of their metal content.

Geological setting, characteristics of the deposit itself, and detailed geochemical analyses of rocks in and around the deposit.

A geologic map constructed primarily from reconnaissance studies from the 1950s to 1990s. The rocks of the map area range from Proterozoic age metamorphic rocks of the Kanektok metamorphic complex to Quaternary age mafic volcanic rocks of Nunivak Island.

Data to determine the distribution of uranium deposits, breccia pipes, and collapse features and define areas permissible for uranium-bearing breccia pipes in northern Arizona and southeast Utah. Data are provided in shapefile format.