Metamorphism (geological)

Process by which rocks are altered in composition and texture by extreme heat, high pressure, or the action of chemicals.
Subtopics:
Alteration (11 items)

Results listed by similarity [list alphabetically]
Data to accompany U.S. Geological Survey Fact Sheet 2020-3017: Pyrrhotite distribution in the conterminous United States

Distribution of the mineral pyrrhotite, an unstable sulfide mineral, across the conterminous United States, to help inform risk assessments. Data are provided in Esri file geodatabase, shapefile, and CSV formats.

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Characterization of Geologic Structures and Host Rock Properties Relevant to the Hydrogeology of the Standard Mine in Elk Basin, Gunnison County, Colorado

Geological and borehole geophysical data and observations collected to characterize the basin and its surface and groundwater flow systems with primary focus on the physical characteristics of the fault vein, related mine workings, and surrounding bedrock

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Chemical alteration index values and rare earth element data and expected ranges for regolith overlying the Stewartsville pluton, Virginia

Whole major element geochemical data used to calculate values of the chemical alteration index (CIA), data for Nd, Sm, Y, and total REE and expected ranges for total REE for samples of regolith overlying the Stewartsville pluton, Virginia. Data are provided in CSV format.

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Chemistry, morphology, modal mineralogy, and photomicrographs of amphiboles and other minerals in the Ironwood Iron-Formation, Gogebic Iron Range, Wisconsin, USA

Information related to amphibole and other minerals in order that commercial, regulatory, and other entities may obtain a better understanding of their impact on potential resource development. Data are provided in Microsoft Excel CSV, annotated PDF reports including microphotographs and analytical results, and JPEG formats.

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Comparative mineral mapping in the Colorado Mineral Belt using AVIRIS and ASTER remote sensing data

A multidisciplinary mapping and data integration project focused on long-term resource planning by the mapping and characterization of exposed surface mineralogy, including that related to hydrothermal alteration and supergene weathering of pyritic rocks.

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Digital map of iron sulfate minerals, other mineral groups, and vegetation of the western United States derived from automated analysis of Landsat 8 satellite data

Multispectral remote sensing data acquired by Landsat 8 Operational Land Imager (OLI) sensor were analyzed using an automated technique to generate surficial mineralogy and vegetation maps of the conterminous western United States. Data are provided in ERDAS Imagine format.

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Digital maps of hydrothermal alteration type, key mineral groups, and green vegetation of the western United States derived from automated analysis of ASTER satellite data

Mineral groups identified through automated analysis of remote sensing data acquired by the ASTER system were used to map the type and spatial distribution of hydrothermal alteration, other exposed mineral groups, and green vegetation.

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Geochemical analyses of bauxite and associated rocks from the Arkansas bauxite region, central Arkansas

Major and trace element analytical results of samples of aluminum ore and nearby rocks in order to understand the prevalence of critical minerals there and in similar deposits. Data are provided in Microsoft Excel, CSV, and shapefile formats.

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Geochemical analyses of surface water, groundwater and springs surrounding Mount Emmons near Crested Butte, Colorado (ver. 2.0, September 2020)

Inorganic chemical analysis of surface- and groundwater and springs in this area to understand natural versus anthropogenic inputs from mineralized and hydrothermally altered areas. Data are provided in Esri file geodatabase, CSV, and shapefile formats.

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Hydrothermal Alteration Maps of the Central and Southern Basin and Range Province of the United States Compiled From Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Data

Maps and data showing the geographic distribution of surficial minerals likely produced by hydrothermal alteration, which may indicate areas permissive of gold and copper mineral deposits.

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Lithogeochemistry of mineralized and altered rock samples from the northern Talkeetna Mountains, south-central Alaska

Chemical analysis of 201 samples of rocks thought to be altered or mineralized in an area containing numerous mines.

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Map showing geology, structure, and geophysics of the central Black Hills, South Dakota

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.

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Maps of hydrothermal alteration in the Basin and Range province of the US

Maps and data showing the geographic distribution of surficial minerals likely produced by hydrothermal alteration, which may indicate areas permissive of gold and copper mineral deposits.

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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.

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Sediment-hosted stratabound copper deposit model

This report describes key features; identifies tectonic-sedimentary environments; illustrates geochemical, geophysical, and geoenvironmental characteristics; evaluates deposit formation; presents exploration and assessment guides; and lists knowledge gaps

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U-Pb SHRIMP and 40Ar/39Ar geochronologic data and backscatter electron (BSE) and panchromatic cathodoluminescent (CL) imagery of sample materials for study of dikes, country rock, and alteration systems, Butte, U.S.A.

Geochronological data using several different techniques, for a multidisciplinary study of dikes, country rock, and alteration systems in which mineral deposits may form. Data are provided in Esri file geodatabase, shapefile, Microsoft Excel, and CSV formats.

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