U.S. Geological Survey
Rare earth elements (REE) are ubiquitous components of our modern society. Though at the bottom of the periodic table, and out of mind for most people, these elements are in our cell phones, computers, vehicles, and even light bulbs. The uses of REE have only increased through time, and they are now playing a key role in the renewable energy revolution. Domestic sources of REE are scarce, with only one operational mine in the country, the Mountain Pass REE mine in southeastern California. It takes unusual geologic conditions to make an REE deposit. Mountain Pass owes its REE abundance to magmas that formed 1.4 billion years ago. A very rare type of magma, called carbonatite, crystallized exotic minerals that concentrated REE to economic grade. Research by the U.S. Geological Survey (USGS) is delineating the physical and chemical paths by which this geologically unique and economically important REE deposit formed. This work builds on USGS research extending back to the deposit’s discovery in the early 1950s. The focus of this lecture will be on the past, present, and future of the Mountain Pass mine through a geologist’s lens.
Central Oregon Geoscience Society
P.O. Box 2154, Bend, Oregon 97709