New Mexico Geological Society Annual Spring Meeting — Abstracts

A full mineralogical characterization of the rock pile material at Molycorp’s Questa molybdenum mine in Taos County, New Mexico required several techniques. This is due to the heterogeneity created by several rock types, supergene alteration, hypogene alteration and recent weathering since rock pile emplacement. Soil petrography was the primary tool used for characterizing samples. Electron microprobe analysis provided micro-scale observations and thin section analysis proved useful for select samples. X-ray diffraction was used to obtain relative clay abundances. Finally, x-ray fluorescence provided whole sample chemistry. Normative mineralogy calculations used the XRF data to acquire overall mineral abundances to supplement other techniques. Using a combination of all tools gave a comprehensive view of the rock pile mineralogy and lithologies.