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John D Horton

Physical Scientist

Geology, Geophysics, and Geochemistry Science Center

Office Phone: 303-236-1921
Fax: 303-236-1425
ORCID: 0000-0003-2969-9073

Box 25046, Denver Federal Center, Mail Stop 973
Denver , CO 80225-0046

Supervisor: Carma A San Juan
The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States ( represents a seamless, spatial database of 48 State geologic maps that range from 1:50,000 to 1:1,000,000 scale. A national digital geologic map database is essential in interpreting other datasets that support numerous types of national-scale studies and assessments, such as those that provide geochemistry, remote sensing, or geophysical data. The SGMC is a compilation of the individual U.S. Geological Survey releases of the Preliminary Integrated Geologic Map Databases for the United States. The SGMC geodatabase also contains updated data for seven States and seven entirely new State geologic...
Categories: Data; Types: ArcGIS REST Map Service, ArcGIS Service Definition, Downloadable, Map Service; Tags: Alabama, Arizona, Arkansas, California, Colorado, All tags...
The mineral pyrrhotite, which is an unstable sulfide mineral, was present in crushed stone aggregate used in concrete foundations of homes in Connecticut and Massachusetts, many of those foundations are failing as the mineral weathers. Because of the substantial costs of lifting homes and replacing their foundations, in 2019 the U.S. Congress directed the U.S. Geological Survey’s (USGS) Mineral Resources Program to help assess the national risk of pyrrhotite in aggregate. The data presented here help form a map that shows where pyrrhotite may occur across the conterminous United States, which can help inform risk assessments. Pyrrhotite occurs in some mineral deposits, and it also forms from pyrite during metamorphism,...
Version 5.0 of these data are part of a larger U.S. Geological Survey (USGS) project to develop an updated geospatial database of mines, mineral deposits, and mineral regions in the United States. Mine and prospect-related symbols, such as those used to represent prospect pits, mines, adits, dumps, tailings, etc., hereafter referred to as “mine” symbols or features, are currently being digitized on a state-by-state basis from the 7.5-minute (1:24,000-scale) and the 15-minute (1:48,000 and 1:62,500-scale) archive of the USGS Historical Topographic Map Collection (HTMC), or acquired from available databases (California and Nevada, 1:24,000-scale only). Compilation of these features is the first phase in capturing...
Categories: Data; Types: ArcGIS REST Map Service, ArcGIS Service Definition, Downloadable, Map Service; Tags: Alabama (AL), Arizona (AZ), Arkansas (AR), California (CA), Colorado (CO), All tags...
This data release consists of point data digitized from structural geologic orientation symbols consisting of mostly foliations and lineations. The data comes from primarily Proterozoic aged rocks in the eastern-central Rocky Mountain Front Range of Colorado. Compilation of the data is from twenty-three geologic maps published by the U.S. Geological Survey and the Colorado Geological Survey between 1964 and 2009, primarily using 7.5-minute, 1:24,000 scale quadrangles. Structural geologic orientation data of planar features (e.g., foliations) and linear features (e.g., fold axes), both with associated attribute values of strike and trend, dip and plunge, location, elevation, and geologic unit were captured for more...
The dataset comprises analyses of core and surface samples collected in and around the Red Mountain porphyry Cu-Mo deposit, Santa Cruz County, Arizona. The dataset includes: analyses for 13 minerals in 245 core samples (Appendix 1); analyses for 44 elements in 818 core samples (Appendix 2); analyses for 54 elements in 122 rock samples (Appendix 3); analyses for 55 elements in 119 soil samples (Appendix 4); and analyses for percent ash and 66 elements in 57 mesquite ash (Appendix 5), 68 oak ash (Appendix 6), and 68 juniper ash (Appendix 7) samples, respectively. The samples were collected and analyzed between 1980 and 2000.
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