January 25, 2023

RESTON, Va. — The U.S. Geological Survey (USGS) and the Colorado Geological Survey are investing $300,000 to map four 7.5-minute quadrangles (Rampant Hills, La Plata, Monument Hills, and Thompson Park) in the historic La Plata mining district along the southwest edge of the San Juan Mountains and eastern portion of the Colorado Plateau in southwestern Colorado. The study area is southwest of the San Juan volcanic field and consists of marine and non-marine sedimentary rocks of Late Paleozoic to Late Mesozoic age. Past mineral production in the district included gold, silver, copper, lead and zinc; critical minerals are associated with these precious and base metal deposits. Potential critical minerals in the project area: palladium, platinum, tellurium, vanadium and zinc. The grants for the geologic mapping come from a$74 million investment allocated earlier this year to the USGS Mineral Resources Program’s Earth Mapping Resources Initiative (Earth MRI), provided through annual appropriations and investments from the Administration’s Bipartisan Infrastructure Law. Overall, the Infrastructure Law is providing an appropriated \$510.7 million investment to the USGS to advance scientific innovation and map critical minerals.

The objectives of this project are to complete new mapping, at a scale of 1:24,000, or more detailed; fill in data gaps among previous maps that partially cover the study area; and provide higher resolution in areas where existing mapping is generalized or unclear. Concurrent geochemical and mineralogical studies are also being conducted. The goal is to better define the surface geology associated with mineral deposits in the La Plata polymetallic district.

The new geologic maps will refine our understanding of the geologic framework of mineral areas of interest. In addition to helping identify mineral potential, these maps also support both decisions about the use of land, water, energy and minerals, and understanding the potential impact of geologic hazards on communities.

Earth MRI is a partnership between the USGS and state geological surveys across America to modernize our understanding of the Nation’s fundamental geologic framework and mineral resources through new geologic maps, geophysical and topographic surveys, and geochemical sampling. The 2022 Bipartisan Infrastructure Law provided additional funding that has accelerated this new mapping in areas with potential for hosting critical mineral resources both still in the ground and in mine wastes.