Research Geologist
Email:
jcolgan@usgs.gov
Office Phone:
303-236-1021
Fax:
303-236-5601
ORCID:
0000-0001-6671-1436
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This digital map shows the areal extent of surficial deposits and rock stratigraphic units (formations) as compiled by Trimble and Machette from 1973 to 1977 and published in 1979 under the Front Range Urban Corridor Geology Program. Trimble and Machette compiled their geologic map from published geologic maps and unpublished geologic mapping having varied map unit schemes. A convenient feature of the compiled map is its uniform classification of geologic units that mostly matches those of companion maps to the north (USGS I-855-G) and to the south (USGS I-857-F). Published as a color paper map, the Trimble and Machette map was intended for land-use planning in the Front Range Urban Corridor. This map recently (1997-1999)...
Tags: Adams County,
Arapahoe County,
Arapahoe Formation,
Colorado,
Colorado Front Range, All tags...
Colorado Piedmont,
Cretaceous rocks,
Dawson Formation,
Denver,
Denver County,
Denver Creek granodiorite,
Denver Formation,
Douglas County,
Economic Geology,
Elbert County,
Front Range Urban Corridor,
GeMS,
Geography,
Geologic Map Schema,
Geologic map,
Glaciology,
Golden,
Golden Fault,
Jefferson County,
Land Use Change,
Mineral Resources,
NCGMP,
NGS,
National Cooperative Geologic Mapping Program,
National Geologic Synthesis Project,
Oligocene bedrock,
Paleocene bedrock,
Paleozoic rocks,
Pierre Shale,
Precambrian rocks,
Quaternary deposits,
Silver Plume quartz monzonite,
Stratigraphy,
Structural Geology,
US GeoFramework Initiative,
USA,
USGI,
USGS Science Data Catalog (SDC),
United States of America,
Wall Mountain Tuff,
aggregate,
alluvial gravel,
eolian sand,
geologic hazard,
land-use planning,
landslide deposit,
mine subsidence,
urban growth,
urban zoning,
windblown sand, Fewer tags
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This dataset captures in digital form the results of previously published U.S. Geological Survey (USGS) Water Mission Area studies related to water resource assessment of Cenozoic strata and unconsolidated deposits within the Mississippi Embayment and the Gulf Coastal Plain of the south-central United States. The data are from reports published from the late 1980s to the mid-1990s by the Gulf Coast Regional Aquifer-System Analysis (RASA) studies and in 2008 by the Mississippi Embayment Regional Aquifer Study (MERAS). These studies, and the data presented here, describe the geologic and hydrogeologic units of the Mississippi embayment, Texas coastal uplands, and the coastal lowlands aquifer systems, south-central...
Tags: 3D,
Alabama,
Arkansas,
Cane River Formation,
Carrizo Sand, All tags...
Cenozoic,
Claiborne Group,
Coastal lowlands aquifer system,
Cockfield Formation,
Cook Mountain Formation,
Eocene,
Geography,
Jackson Group,
Kentucky,
Laredo Formation,
Louisiana,
Lower Claiborne confining unit,
Lower Wilcox aquifer,
McNairy-Nacatoch aquifer,
Memphis Sand,
Middle Claiborne aquifer,
Middle Claiborne confining unit,
Middle Wilcox aquifer,
Midway Group,
Midway confining unit,
Miocene,
Mississippi,
Mississippi River Valley alluvial aquifer,
Mississippi River Valley alluvial aquifer,
Mississippi embayment aquifer system,
Missouri,
NCGMP (National Cooperative Geologic Mapping Program),
National Cooperative Geologic Mapping Program,
National Geologic Synthesis Project,
Oklahoma,
Oligocene,
Paleocene,
Pliocene,
Quaternary,
Regional Aquifer System Analysis,
Sparta Sand,
Tennessee,
Tertiary,
Texas,
Texas coastal uplands aquifer system,
US GeoFramework Initiative,
USGI,
USGS Science Data Catalog (SDC),
United States GeoFramework Initiative,
Upper Claiborne Aquifer,
Upper Wilcox aquifer,
Vicksburg Group,
Wilcox Group,
Yegua Formation,
alluvial,
borehole,
elevation,
elevation,
environment,
hydrogeologic,
marine shale,
sandstone,
stratigraphic thickness,
structure contours,
thickness,
three dimensional, Fewer tags
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This data release presents geologic map data for the bedrock geology of the Blanca Peak, Walsenburg, Trinidad, and Alamosa 30' x 60' quadrangles, Colorado. Geologic mapping incorporates new interpretive contributions and compilation from published geologic map data sources primarily ranging from 1:24,000 to 1:50,000 scale. Much of the geology incorporated from published geologic maps is adjusted based on digital elevation model and natural-color image data sources to improve spatial resolution of the data. Spatial adjustments and new interpretations also eliminate mismatches at source map boundaries. This data set represents only the bedrock geology; deposits of unconsolidated, surficial materials that are typically,...
Categories: Data;
Tags: Colorado,
Espanola Basin,
Geography,
Laramide orogeny,
Mazatzal terrane, All tags...
New Mexico,
Rio Grande Rift,
San Juan Basin,
San Juan Mountains,
San Luis Valley,
Southern Rocky Mountains,
Southern Rocky Mountains volcanic field,
Taos Plateau volcanic field,
USGS Science Data Catalog (SDC),
Western Interior Basin,
Yavapai terrane,
faulting,
geologic maps,
igneous rocks,
metamorphic rocks,
sedimentary rocks, Fewer tags
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Note: this data release has been deprecated. Please see new data release here: https://doi.org/10.5066/P9F0X0YF. This dataset captures in digital form the results of previously published U.S. Geological Survey (USGS) Water Mission Area studies related to water resource assessment of Cenozoic strata and unconsolidated deposits within the Mississippi Embayment and the Gulf Coastal Plain of the south-central United States. The data are from reports published from the late 1980s to the mid-1990s by the Gulf Coast Regional Aquifer-System Analysis (RASA) studies and in 2008 by the Mississippi Embayment Regional Aquifer Study (MERAS). These studies, and the data presented here, describe the geologic and hydrogeologic...
Tags: 3D,
Alabama,
Arkansas,
Cane River Formation,
Carrizo Sand, All tags...
Cenozoic,
Claiborne Group,
Coastal lowlands aquifer system,
Cockfield Formation,
Cook Mountain Formation,
Energy Resources,
Eocene,
Jackson Group,
Kentucky,
Laredo Formation,
Louisiana,
Lower Claiborne confining unit,
Lower Wilcox aquifer,
McNairy-Nacatoch aquifer,
Memphis Sand,
Middle Claiborne aquifer,
Middle Claiborne confining unit,
Middle Wilcox aquifer,
Midway Group,
Midway confining unit,
Miocene,
Mississippi,
Mississippi River Valley alluvial aquifer,
Mississippi River Valley alluvial aquifer,
Mississippi embayment aquifer system,
Missouri,
NCGMP (National Cooperative Geologic Mapping Program),
Oklahoma,
Oligocene,
Paleocene,
Pliocene,
Quaternary,
Regional Aquifer System Analysis,
Sedimentology,
Sparta Sand,
Stratigraphy,
Tennessee,
Tertiary,
Texas,
Texas coastal uplands aquifer system,
US GeoFramework Initiative,
USGI,
United States GeoFramework Initiative,
Upper Claiborne Aquifer,
Upper Wilcox aquifer,
Vicksburg Group,
Water Resources,
Wilcox Group,
Yegua Formation,
alluvial,
borehole,
elevation,
elevation,
environment,
hydrogeologic,
marine shale,
sandstone,
stratigraphic thickness,
structure contours,
thickness,
three dimensional, Fewer tags
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This dataset is the assembled analytical results of geochemical, petrographic, and geochronologic data for samples, principally those of unmineralized Tertiary volcanic rocks, from the Tonopah, Divide, and Goldfield mining districts of west-central Nevada. Much of the data presented here for the Tonopah and Divide districts are for samples collected by Bonham and Garside (1979) during geologic mapping in and around those districts, whereas much of that for samples from the Goldfield district were obtained by Ashley (1974; 1979; 1990). Additional data were derived from samples collected between 2012–2017, as part of the U.S. Geological Survey Mineral Resources Program funded project titled: “Magmatic-tectonic history...
Categories: Data;
Tags: Ar,
Divide mining district,
Economic Geology,
Esmeralda County,
Fraction Tuff, All tags...
GGGSC,
Geochemistry,
Geology, Geophysics, and Geochemistry Science Center,
Goldfield mining district,
Heller Tuff,
ICP–AES,
ICP–MS,
LA-ICPMS,
MRP,
Mineral Resources,
Mineral Resources Program,
Nevada,
New Mexico Geochronology Research Center,
Nye County,
Pb,
SHRIMP-RG,
Sensitive High Resolution Ion Microprobe with Reverse-Geometry,
Siebert Tuff,
Tonopah mining district,
U,
U.S. Geological Survey,
USGS,
USGS Science Data Catalog (SDC),
Walker Lane geologic province,
argon,
geochemistry,
geochronology,
geoscientificInformation,
inductively coupled plasma—atomic emission spectrometry,
inductively coupled plasma—mass spectrometry,
laser ablation inductively coupled plasma—mass spectrometry,
lead,
petrography,
precious metal deposits,
uranium,
volcanic rocks,
wavelength dispersive X-ray fluorescence spectrometry, Fewer tags
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