Geology and mineral resources of the Laughlin Peak mining district, Colfax County, New Mexico
V. T. McLemore
The Laughlin Peak district in the Laughlin Peak-Chico Hills igneous complex is in the southern portion of the younger Raton-Clayton volcanic field, southeast of Raton in northeastern New Mexico, along the Jemez Lineament, and is part of the North American Cordilleran alkaline-igneous belt that extends from Alaska and British Columbia southward into New Mexico and eastern Mexico. The Laughlin Peak-Chico Hills complex was emplaced just before or at the beginning of Rio Grande rift extension (22–37 Ma). Host rocks in the Laughlin Peak district are alkaline, predominantly ferroan, predominantly metaluminous to peralkaline and plot as A-type granites, WPG (within-plate granites), and active continental margins zone. The igneous rocks exhibit typical light rare earth elements (REE) enriched chondrite-normalized REE patterns of alkaline rocks with no europium anomaly. The alkaline igneous rocks in the district are similar in composition and texture to igneous rocks found in two other REE districts in the North American Cordilleran alkaline-igneous belt (also known as the Great Plains Margin or GPM) in New Mexico, the Gallinas and Cornudas Mountains. Although there has been no mineral production from the Laughlin Peak district, three types of mineral deposits have been identified: (1) carbonatites, (2) breccia pipe deposits, and (3) Th-REE hydrothermal veins. Since 1987, only minor exploration of these deposits occurred because of low commodity prices and environmental concerns. However, as the current demand for critical commodities like REE has increased, new exploration programs have encouraged additional research on the geology of these deposits. Thorium, REE and possibly gold are potential commodities in the Laughlin Peak district, but additional drilling is required to fully understand the mineral resource potential. Detailed studies on the mineralogy and paragenesis also are required in the Laughlin Peak district and should be completed before advanced exploration. These studies will greatly enhance exploration efforts. The diversity of igneous rocks and associated mineral deposits along the boundary of the Great Plains with the Southern Rocky Mountain and Basin and Range provinces suggests that this region is characterized by multiple pulses of highly fractionated and differentiated magmas. In the Laughlin Peak-Chico Hills complex, two different chemical trends of phonolite are found that could be a result of differences in fractionation. Both upper mantle and lower crustal source rocks may be involved, although in the Laughlin Peak-Chico Hills complex, a lower crustal source with possible mixing of upper crustal rocks is suggested by geochemical data. Deep-seated fracture systems or crustal lineaments, such as the Jemez Lineament, apparently channeled the magmas and hydrothermal fluids. Once magmas and metal-rich fluids reached shallow levels, the distribution and style of these intrusions, as well as the resulting associated mineral deposits, were controlled by local structures and host rock compositions.
- McLemore, V. T., 2015, Geology and mineral resources of the Laughlin Peak mining district, Colfax County, New Mexico, in: Geology of the Las Vegas Region, , New Mexico Geological Society, Guidebook, 66th Field Conference, pp. 277-288.