REE Wyoming Production/Exploration and Current Research
Wyoming has good potential to mine rare earth elements (REE) in the future. Rare earths are found in several different geologic environments across state. However, only one deposit near Sundance, Wyoming is currently under investigation with mining operations planned in the coming years.
Over the last decade Rare Element Resources, Ltd. has been investigating the REE-bearing carbonatite dike complex in the Bear Lodge Mountains; one of the largest deposits in the United States.
The Bear Lodge REE deposit is centered on carbonatite dikes associated with Eocene (46 to 50 Ma) alkalic intrusive rocks. In this deposit, the minerals ancylite and bastnasite contain most of the REE, which are dominated by the Light Rare Earth Element cerium, lanthanum, neodymium, and praseodymium. However, at the Whitetail Ridge deposit and the Carbon target, Heavy Rare Earth Elements-enrichment primarily occurs as elevated yttrium-HREE in parasite and synchysite; at Taylor Ridge and westward, yttrium-HREE enrichment appears to occur within xenotime and an unidentified yttrium-vanadium phosphate. Potential exists in other parts of Wyoming for the discovery of carbonatites that host REE.
Historically, in the 1950s minor amounts of REE-bearing minerals were mined from a Precambrian pegmatite in Carbon County. Over the last three years, the Wyoming State Geological Survey has sampled and analyzed a few of the potential REE host rocks within the state. Prior to this fieldwork, most early investigations identified the potential for occurrences of REE in studies related to uranium and thorium, but did not produce detailed analyses due to high costs related to analytical technology of the time. However, modern technology has significantly reduced these costs. With the completion of the most recent WSGS Mineral Investigation on rare earths, for the first time in the history of this research the state and commercial interests have access to detailed analyses of REE in Wyoming. The WSGS believes these results as well as the online database of sites and samples will be useful to the state Legislature as well as commercial interests interested in further exploration of REE and other mineral commodities.
Map of the Rare Element Resources, Ltd. Bear Lodge Project area.
(John Ray, Rare Element Resources, Inc., 2013.)