New Mexico Geological Society Annual Spring Meeting — Abstracts

Rare earth elements (REE) and critical minerals (CM) have become of great economic interest because of the advent of new technologies and recent geopolitical unrest affecting the supply of resources. With the continuous development of extracting REE and CM from secondary and non-conventional sources such as coal and its related strata, there is a push to study the relationship between coal, REE, and CM. Extracting REE and CM from coal and coal ash could become feasible because of the large volumes of coal burned for electricity and the resulting storage facilities of coal ash. The San Juan Basin in northern New Mexico is a structural basin that contains coal and related stratigraphic units with elevated concentrations of REE and CM. This basin is being assessed geochemically through whole-rock and coal ash analysis to determine if there is REE and CM enrichment. The San Juan Basin contains three major coal-bearing sequences, ascending in oldest to youngest stratigraphic order: Crevasse Canyon, Menefee, and Fruitland formations. There are 22 individual coalfields within the San Juan basin, eight are Crevasse Canyon formation coalfields, 11 are Menefee formation coalfields, and four are Fruitland formation coalfields. 23 individual holes of legacy drill core from the San Juan Basin have been logged and photographed. They have been logged to record basic geological characteristics of the coal seams and related strata observed. Samples of coalbeds, coal seams, overlying, and underlying rock units continue to be collected and characterized to determine any economic viability. Coal ash samples from the San Juan Basin have shown a greater than 200 ppm total REE, which is considered enriched for these rocks. CM in coal samples from the Salt Lake and Star Lake coalfields show Li and Zr having slightly elevated concentrations when compared to the other San Juan Basin coal samples and average crustal abundance. Historic data has been collected and compiled into a new comprehensive coal geochemical database with the new chemical analyses. This database will grow with additional analysis and serves as the dataset for this project. To determine the economic viability, the coal volume resource potential has been calculated using estimated resource figures defined by NMBGMR and USGS. REE and CM have been applied to these calculations to estimate the resource potential in the San Juan Basin.