The California Geological Survey (CGS) is conducting geochemical reconnaissance sampling for critical minerals in California. This web page contains the results of those reconnaissance efforts.
The goal of the sampling program is to collect data that will support current and future critical-mineral, precious-metal, base-metal, and industrial-mineral activities in California. Critical minerals as defined by the U.S. Department of Interior are mineral resources that are essential to our economy and national security and are at risk for supply disruption.
DR 2026-01 – Geochronology and Geochemistry Data Release for the New York Mountains Earth MRI Project, San Bernardino County, California: U-Pb Radiometric Dating, Luminescence Dating, and Geochemistry
Map showing geochronologic and geochemical sample sites relative to the four topographic quadrangles (black outlines) included in the CGS Mineral Resources Program Earth MRI mapping project for the New York Mountains. The project area is in eastern San Bernardino County, adjacent to the California-Nevada border.
Compiled by Brian J. Swanson (CGS), PG, CEG, David Reioux (CGS), PG, Benjamin M. Parrish (CGS), PG, Matthew J. Towne (CGS), Joshua J. Schwartz (CSUN), and Shannon A. Mahan (USGS)
Summary of DR 2026-01
As part of the CGS Mineral Resources Program Earth MRI mapping project for four quadrangles in the New York Mountains, CGS staff collected samples of rocks ranging in age from Proterozoic to Mesozoic for U-Pb radiometric dating and geochemical analyses. The Proterozoic rocks in the New York Mountains a re closely related to the rocks that host the Mountain Pass Rare Earth Element (REE) deposits in the Clark Range, northwest of the study area. Proterozoic and Mesozoic rocks containing gold and other precious metals also occur within the historic Vanderbilt mining area in the New York Mountains. The U-Pb dating and geochemical analyses can be used to constrain the timing of the Kokoweef and Ivanpah orogenies and identify areas with mineral-resource potential. Samples of older alluvial-fan sediments were collected for Infrared Stimulated Luminescence (IRSL) dating, which can be used to better understand the Quaternary history of the area and help identify areas susceptible to debris flow hazards.
DR 2024-1 - Data Release for the Del Norte Nickel-Cobalt Laterite Geochemical Reconnaissance Project
Map showing location and size of reconnaissance area (black outline), and distribution of sample locations (blue dots). Location: north-central Del Norte County. Size: roughly 15 miles across in all directions. There are approximately 90 sample locations, distributed toward the perimeter of the recon area.
by Ben Parrish, PG and Amy Tuzzolino, PG
Summary of DR 2024-1
The CGS conducted geochemical reconnaissance sampling of laterite and associated ultramafic rocks in Del Norte County as part of its statewide geochemical reconnaissance initiative. The Del Norte County laterite deposits have historically been mined for nickel, cobalt, and chromium. Samples from laterite and ultramafic rocks of the Josephine Ophiolite in Del Norte County were collected for geochemical analyses. Samples were selected to evaluate trace-element signatures and distribution in laterite deposits and compare trace-element concentration in underlying ultramafic rocks. Samples were also selected to evaluate laterite enrichment processes for nickel, cobalt, and chromium in these deposits.
