Research Geophysicist
Geology, Geophysics, and Geochemistry Science Center
Email:
anne@usgs.gov
Office Phone:
303-236-1397
Fax:
303-236-1425
ORCID:
0000-0001-5574-9201
Supervisor:
Paul A Bedrosian
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Regional geophysical data grid files (provided in Grid eXchange File format) were used to study crustal architecture beneath the Southern Midcontinent (USA) by McCafferty and others (2019). The study covered a rectangular, multi-state area of 924 by 924 kilometers centered on Missouri, and a corresponding volume extending from the topographic surface to a depth of 50 kilometers below sea level. The observed geophysical data grids (Bouguer gravity anomaly and reduced-to-pole (RTP) aeromagnetic anomaly) were used in 3D inversions, and the calculated geophysical data grids were produced by the inversions. All grids are sampled at a 2,000 by 2,000 meter grid interval.
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The Mohorovicic discontinuity or 'Moho' maps the boundary between the earth's crust and mantle and is defined by an abrupt change in seismic velocity due to changes in the density of rocks between the crust and mantle. GeoTIFF grids that map depth to Moho (crustal thickness) for the United States and Canada, and for Australia are provided in this report and were used as evidential layers in developing prospectivity models for basin-hosted Pb-Zn mineralization (Lawley and others, 2022). A composite grid of Moho depths across the United States and Canada was created using data from Shen and Ritzwoller (2016) for the conterminous United States, from Zhang and others (2019) for Alaska, and from Schetselaar and Snyder...
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Australia,
CMMI,
Canada,
Critical Minerals Mapping Initiative,
Exploring for the Future Program, All tags...
GA,
GGGSC,
GSC,
Geological Survey of Canada,
Geology, Geophysics, and Geochemistry Science Center,
Geoscience Australia,
MRP,
Mineral Resources Program,
Moho,
Mohorovičić discontinuity,
TGI,
Targeted Geoscience Initiative,
U.S. Geological Survey,
USGS,
United States,
critical minerals,
crustal structure,
crustal thickness,
depth to Moho,
geophysics,
geoscientificInformation,
lead,
magnetic field (earth),
mantle,
mantle (earth),
maps and atlases,
metallic mineral resources,
mineral resources,
zinc, Fewer tags
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Several evidential layers calculated from the national-scale gravity anomaly map of Australia (Geophysical Acquisition and Processing Section, 2020) are provided here. This directory includes GeoTIFF grids of Bouguer gravity, the horizontal gradient magnitude of the Bouguer gravity, the Bouguer gravity upward continued 30 km, and the horizontal gradient magnitude of the upward continued gravity, The directory also includes shapefiles of locations that trace the maxima of the horizontal gradient magnitude of the gravity and of the maxima of the horizontal gradient magnitude of the upward continued gravity. Otherwise known as “worms”, the points tracking the maxima mark the edges of shallow density sources (in the...
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Australia,
Bouguer gravity,
CMMI,
Critical Minerals Mapping Initiative,
Exploring for the Future Program, All tags...
GA,
GGGSC,
GSC,
Geological Survey of Canada,
Geology, Geophysics, and Geochemistry Science Center,
Geoscience Australia,
MRP,
Mineral Resources Program,
TGI,
Targeted Geoscience Initiative,
U.S. Geological Survey,
USGS,
critical minerals,
geophysics,
geoscientificInformation,
gravity,
gravity anomaly,
ground gravity,
horizontal gradient magnitude,
horizontal gradient magnitude maxima,
lead,
maps and atlases,
metallic mineral resources,
mineral resources,
zinc, Fewer tags
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This publication provides digital flight line data for a high-resolution horizontal magnetic gradient and radiometric survey over an area of southeast Missouri and western Illinois. The survey represents the first airborne geophysical survey conducted as part of the U.S. Geological Survey (USGS) Earth Mapping Resource Initiative (Earth MRI) effort (Day, 2019). Earth MRI is a cooperative effort between the USGS, the Association of American State Geologists, and other Federal, State, and private sector organizations to improve our knowledge of the geologic framework of the United States. Data for this survey were collected by Terraquest, Ltd. under contract with the USGS using a fixed wing aircraft with magnetometers...
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Earth Mapping Resources Initiative,
EarthMRI,
GGGSC,
Geology, Geophysics, and Geochemistry Science Center,
Illinois, All tags...
Ironton,
MRP,
Mineral Resources Program,
Missouri,
USGS Science Data Catalog (SDC),
aeromagnetic surveying,
aeroradiometric surveying,
airborne geophysical survey,
economy,
geophysics,
geoscientificInformation,
geospatial datasets,
horizontal magnetic gradiometry,
none,
potassium,
thorium,
uranium, Fewer tags
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Airborne radiometric data are provided here as part of the data release "Airborne magnetic and radiometric survey, western Arkansas, 2022." This website includes the processed radiometric data, with and without spectra, provided in ASCII .csv files and geoTIFF images showing the total count (K, U, Th), percent potassium (%K), equivalent uranium (eU), and equivalent thorium (eTh).
Categories: Data;
Types: Downloadable,
GeoTIFF,
Map Service,
Raster;
Tags: AASG,
Arkansas,
Association of State Geologists,
Dardanelle,
Dardanelle Lake, All tags...
Earth MRI,
Earth Mapping Resources Initiative,
GGGSC,
Garland,
Geology, Geophysics, and Geochemistry Science Center,
Johnson,
Logan,
MRP,
Mineral Resources Program,
NCGMP,
National Cooperative Geologic Mapping Program,
Ouachita National Forest,
Petit Jean,
Pope,
Saline,
Scott,
U.S. Geological Survey,
USA,
USGS,
United States,
United States of America,
Yell,
aeromagnetic surveying,
aeroradiometric surveying,
airborne geophysical survey,
critical minerals,
economic geology,
economy,
geophysics,
geoscientificInformation,
geospatial datasets,
potassium,
structural geology,
thorium,
uranium,
west-central Arkansas,
western Arkansas,
western Arkansas, Fewer tags
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