Volcanic rocks

A generally finely crystalline or glassy igneous rock resulting from volcanic action at or near the earth's surface, either ejected explosively or extruded as lava. The term includes near-surface intrusions that form a part of the volcanic structure.
This category is also used for lava, pyroclastic, tuff, and volcanic ash.
Subtopics:
(none)


Results listed by similarity [list alphabetically]
A geochemical isotopic (Nd-Pb) comparison of volcanic rocks erupted during the last 3,550 yrs. B.P. of interplinian activity of Somma-Vesuvius Volcano, southern Italy

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.

Info
Petrology of volcanic rocks associated with silver-gold (Ag-Au) epithermal deposits in the Tonopah, Divide, and Goldfield Mining Districts, Nevada

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

Info
Geochronology and correlation of Tertiary volcanic and intrusive rocks in part of the southern Toquima Range, Nye County, Nevada

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.

Info
Bedrock geologic map of the Ashland and the northern part of the Ironwood 30 min X 60 min quadrangles, Wisconsin and Michigan

Info
Geochronology of Cenozoic rocks in the Bodie Hills, California and Nevada

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.

Info
Geophysical, geochemical, mineralogical, and enivronmental data for rock samples collected in a mineralized volcanic environment, upper Animas River watershed, Colorado

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.

Info
Net acid production, acid neutralizing capacity, and associated mineralogical and geochemical characteristics of Animas River watershed igneous rocks near Silverton, Colorado

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

Info
Regional mapping of hydrothermally altered igneous rocks along the Urumieh-Dokhtar, Chagai, and Alborz Belts of western Asia using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data and Interactive Data Language (IDL) logical oper

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.

Info
Alaska Geochemical Database (AGDB)-Geochemical data for rock, sediment, soil, mineral, and concentrate sample media

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.

Info
Alaska Geochemical Database Version 3.0 (AGDB3)—Including “Best Value” Data Compilations for Rock, Sediment, Soil, Mineral, and Concentrate Sample Media

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

Info
Alaska Geochemical Database, v2

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

Info
Alaska Geochemical Database, Version 2.0 (AGDB2)--including "best value" data compilations for rock, sediment, soil, mineral, and concentrate sample media

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.

Info
Bedrock geologic map of the Port Wing, Solon Springs, and parts of the Duluth and Sandstone 30 X 60 minute quadrangles, Wisconsin

Info
Geochemical and petrographic data for intrusions peripheral to the Big Timber Stock, Crazy Mountains, Montana

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

Info
Geochronology and geology of late Oligocene through Miocene volcanism and mineralization in the western San Juan mountains, Colorado

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

Info
Geologic and mineralogic controls on acid and metal-rich rock drainage in an alpine watershed, Handcard Gulch, Colorado

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.

Info
Geologic map of the Bodie Hills, California and Nevada

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.

Info
Geologic map of the east half of the Lime Hills 1:250,000-scale quadrangle, Alaska

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.

Info
Porphyry copper assessment of Central America and the Caribbean Basin

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.

Info
Porphyry copper assessment of eastern Australia

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.

Info
Porphyry copper assessment of northeast Asia: Far East Russia and northeasternmost China

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.

Info
Rare earth element mineralogy, geochemistry, and preliminary resource assessment of the Khanneshin carbonatite complex, Helmand Province, Afghanistan

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

Info
Reconnaissance geologic map of the Kuskokwim Bay region, southwest Alaska

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.

Info