A geochemical survey of ferrous and selected base metals in the eastern half of the Capitan Mountains, Lincoln County, New Mexico
Scott T. Ellinger and Joseph C. Cepeda
Anomalous amounts of ferrous and base metals, including Cu, Fe, Mg, Mn, Mo, Pb and Zn, have been detected in bulk and panned-concentrate stream sediment samples collected from major drainages extending from the Capitan Mountains. The highest concentrations were detected near magnetite-rich skarn mineralization near the contact of the Capitan pluton and the Permian sedimentary section, or in some cases, downstream from the contact where iron-rich alluvium enters stream channels. In bulk samples, Fe concentrations range from 13,600 to 217,200 ppm, Mn ranges from 100 to 1825 ppm, and Mg ranges from 475 to 220,325 ppm. In panned-concentrate samples, Fe and Mn concentrations increase while Mg decreases. Mo, Pb, and Zn concentrations range from 25 to 2550 ppm in panned concentrate. Erosion has removed most of the skarn deposits that formed at the margin of the pluton. Metals formerly contained in these deposits are now incorporated in the alluvial blanket surrounding the range. National Uranium Resource Evaluation anomalies of Ce, La, Nb and Y coincide with Fe and Mn anomalies of this study. Rare-earth-element mineralization may be present within the pluton and as alluvial concentrations of REE-bearing minerals such as sphene or bastnaesite.
- Ellinger, Scott T.; Cepeda, Joseph C., 1991, A geochemical survey of ferrous and selected base metals in the eastern half of the Capitan Mountains, Lincoln County, New Mexico, in: Geology of the Sierra Blanca, Sacramento and Capitan Ranges, New Mexico, Barker, James M.; Kues, Barry S.; Austin, George S.; Lucas, Spencer, G., New Mexico Geological Society, Guidebook, 42nd Field Conference, pp. 299-304.