skip all navigation
skip banner links
skip primary navigation

Carbonatites in the Lemitar Mountains

Masked students are posed on top of a carbonatite (dark brown dike) in the Lemitar Mountains, Socorro County, NM.
(click for a larger version)
Ginger McLemore

Lemitar Mountains, NM
— March 2, 2021

Studying carbonatites in the Lemitar Mountains, north of Socorro, New Mexico during a pandemic! Carbonatites are carbonate-rich rocks containing more than 50% magmatic carbonate minerals, less than 20% SiO2, are of magmatic derivation, and typically found in zoned complexes consisting of alkaline igneous and/or carbonatite stocks, ring dikes, and cone sheets. Carbonatites generally contain high concentrations of rare earth elements (REE), U, Th, Nb, Ta, Zr, Hf, Fe, Ti, V, Cu, Sr, apatite, magnetite, vermiculite, and barite. China currently produces 80-95% of the REE in the world and most of that production is from carbonatites. More than 100 carbonatite dikes intruded a complex Proterozoic granitic and metamorphic terrain in the Lemitar Mountains and consist of greater than 50% calcite and dolomite, 5-15% magnetite, 10-20% biotite, phlogopite, muscovite, and chlorite, 5-10% apatite, and various amounts of accessory minerals (bastnaesite, fluorite, barite). Bastnaesite, apatite, and other accessory minerals contain the REE. Age dating shows that the carbonatites are ~504 Ma. REE are increasingly becoming more important in our technological society and are used in many of our electronic devices, like computers, laptops, cell phones, electric vehicles, wind turbines, solar panels, and many other uses.

— Ginger McLemore, NMBGMR Principar Senior Economic Geologist