14-6 EarthMRI-Supported Geologic Mapping and Geochemical Investigations in Colorado Critical Mineral Focus Areas

Session: Linking Mineral Resources and the Geologic Framework of North America: The USGS Earth Mapping Resources Initiative (Earth MRI) and Related Activities

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The Colorado Geological Survey (CGS), in partnership with the U.S. Geological Survey (USGS), is conducting Earth Mapping Resources Initiative (EarthMRI) projects across multiple Colorado critical mineral focus areas (focus areas). These efforts include geologic mapping, geochemical sampling, and USGS-led airborne geophysical surveys to advance critical mineral research and exploration. In the Wet Mountain area of south-central Colorado, USGS EarthMRI- and CGS-supported geologic compilation mapping and new geochemical investigations have produced detailed surficial maps and an updated geochemical data set for rock types in several focus areas. These products aid in the interpretation of recent USGS geophysical survey data, confirm elevated critical mineral concentrations in carbonatites and other associated rocks, and contribute to ongoing CGS studies as well as recently published research.

In southwestern Colorado, recent USGS EarthMRI- and CGS-supported geologic mapping and geochemical studies in the La Plata polymetallic focus area are providing new 1:24,000-scale maps and geochemical data sets to refine local rock type classification and clarify the region’s intrusive history. This investigation will provide insight into the ore deposits and critical mineral potential of the area while aiding in the interpretation of recent USGS geophysical data and local exploration activities.

An EarthMRI-supported CGS reconnaissance of historic mine waste identified elevated concentrations of critical minerals, base metals, and precious metals in waste rock and tailings from several select focus areas and historic mining districts. These findings provide new geochemical data to support future economic assessments and further investigation of mine waste for potential critical mineral recovery and waste management. This investigation also enhances our understanding of the concentration of critical minerals in deposit types with limited geochemical data. Additional EarthMRI projects include the reanalysis of archived USGS sediment samples from the Paradox Basin focus area using modern laboratory methods to generate an updated geochemical dataset.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-8249

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