Heavy mineral, beach-placer sandstone deposits at Apache Mesa, Jicarilla Apache Reservation, Rio Arriba County, New Mexico
Cretaceous heavy mineral, beach-placer sandstone deposits are found in the Point Lookout Sandstone on the Jicarilla Apache Reservation, Rio Arriba County, New Mexico. Beach-placer sandstone deposits are characterized by relatively high accumulations of heavy, resistant minerals (i.e., high specific gravity) that form on the upper regions of beaches or in long-shore bars in a marginal-marine environment. They form by mechanical concentration (i.e., settling) of heavy minerals by the action of waves, currents, and winds. Modern examples are found along the Atlantic Coast in the United States, southeastern Australia, and Andhra Pradesh in India, where these deposits are mined for titanium, zircon, and locally, monazite (a Ce-bearing rare earth elements mineral). Other potential commodities include niobium, chromium, thorium, and rare earth elements (REE). The Apache Mesa beach-placer sandstone deposits are similar in origin, texture, mineralogy, and chemical composition to beach-placer sandstone deposits elsewhere in the San Juan Basin and in the world. The Apache Mesa beach-placer sandstone deposit contains only 132,900 short tons (120,564 metric tons) of ore with grades of 3% TiO2, 108 ppm Cr, 46 ppm Nb, 2,187 ppm Zr, 40 ppm Th, and 522 ppm total REE. Modern, economic beach-placer sandstone deposits are typically greater than 10 million short tons of greater than 2% heavy minerals and are mined by open-pit methods. Geologic mapping and drilling indicate that the Apache Mesa beach-placer sandstone deposits are too small and low grade to be economic in today’s market. No further investigation is recommended at this time.
- McLemore, V.T., 2017, Heavy mineral, beach-placer sandstone deposits at Apache Mesa, Jicarilla Apache Reservation, Rio Arriba County, New Mexico, in: The Geology of the Ouray-Silverton Area, Karlstrom, Karl E.; Gonzales, David A.; Zimmerer, Matthew J.; Heizler, Matthew; Ulmer-Scholle, Dana S., New Mexico Geological Society, Guidebook, 68th Field Conference, pp. 123-132.