NEWS RELEASE: WY Geological Survey Provides Results of Study on Rare Earth Elements

 Wyoming Geological Survey Provides Results of Statewide 
Study on Rare Earth Elements

Wyoming’s mineral wealth may soon include rare earth elements (REEs) – used in numerous high-tech devices – with mining operations planned for the Bear Lodge Mountains in Crook County and the potential for additional REE deposits in the state. 

The Wyoming State Geological Survey (WSGS) recently completed a Report of Investigations on the state’s REEs – from sampling and mapping their locations, to measuring and recording their abundances. The full-color report titled “Rare Earth Elements in Wyoming” includes maps and analyses, and is available via the WSGS Online Store as well as in a downloadable pdf format, along with an online database and interactive map of the sample sites.

“With this scientific study our agency has confirmed rare earth elements occur in a variety of geologic settings across Wyoming,” says Tom Drean, director of the WSGS. 

“I commend the Wyoming Legislature for taking another positive step in evaluating the natural resources of the state.” The Legislature allocated $200,000 of Abandoned Mine Lands Reclamation funds for the WSGS to conduct the statewide study. 

Knowledge of REEs is the first step in the process of commercial exploration, says Drean. “If rare earth elements are found in high enough quantities in Wyoming, mining could be economically feasible in the future, placing the United States once again in the competitive global market for the production of rare earth materials,” he says.

WSGS collected 289 samples from known or potential host rocks of REEs and other minerals, and analyzed these along with another 67 previously collected samples. 

The samples were then sent to a lab and analyzed for REEs and other potential economic metals or elements.

“Although rare earth elements are relatively abundant in the earth’s crust, they are rarely concentrated into mineable ore deposits,” says Wayne Sutherland, WSGS gems and minerals geologist. “Certain concentrations of elements can be clues that other economic deposits exist in the same area,” he says. “For example, an abundance of arsenic in some geological settings is considered a pathfinder for gold.” 

In addition to the report, WSGS also developed the Wyoming Database of Geology (Wyo-DOG), cataloguing the sampling results, and while developed for this project the database will also be used for other geological investigations. One query of the database indicated that samples containing at least five times the average crustal abundance of REEs, a measurement suggestive of the potential for further exploration, showed 20 sites in Wyoming at or above this amount. The database includes all elemental analyses along with brief write-ups and photographs of most samples and sites, according to Sutherland, lead geologist of the project. 

“Wyo-DOG makes the results of this study available to a wide audience,” says Sutherland. Data from Wyo-DOG can be displayed in several formats, including ArcGIS and Google Earth. A map of the sample sites is available at www.wsgs.uwyo.edu/Research/Minerals/Wyo-Dog.aspx. 

REEs are a group of 17 chemical elements that occur together in the periodic table. Sixteen of these occur in nature and are typically found in varying proportions in the same ore deposits. The group consists of yttrium and 15 lanthanide elements. Scandium is found in most rare earth element deposits and is sometimes classified as a rare earth element. These elements are used in many devices that people use every day, such as computer memory, DVDs, rechargeable batteries, and cell phones. Europium is used in florescent lamps; samarium and neodymium are used in magnets, and samarium for precision-guided weapons. 

China currently dominates the supply and export of REE worldwide (approximately 97 percent). The country exported more than 40,000 metric tonnes of rare earth metals in 2012. Up until 1996 the United States and China produced equal quantities of rare earths. Since then mining of rare earths in the United States has been on the decline because of the cost and time involved in pre-mining efforts. According to the U.S. Geological Survey, deposits of REE-bearing ore exist in California (Molycorp Mountain Pass mine), Nebraska, Colorado, New Mexico, Texas, New York, Alaska, and Wyoming.

Molycorp’s Mountain Pass mine in California is currently the only active mine in the United States. Near Sundance, Wyoming, the Bear Lodge deposit (owned by Rare Element Resources, Ltd.) is considered one of the largest potential sources of the minerals in North America. 

The total reserves of rare earths in the world are estimated to be around 99 million tonnes; China controls most of these reserves. REEs are also produced in Australia, India, Malaysia, Russia, and Thailand. Kazakhstan, Mongolia and Afghanistan have also announced plans to bring new supplies to market. 

“With this knowledge that rare earths occur in Wyoming, some of these sites may be worthy of further investigation, which in the future could add to Wyoming’s mineral resource portfolio,” says Drean. 

For additional information, log on to the WSGS website on Wyoming Rare Earth Elements, at www.wsgs.uwyo.edu/research/minerals/Rare-Earths.aspx.

Photomicrograph of allanite in plane-polarized light.
Sample from Holiday Place pegmatite near Tie Siding, Wyoming. 

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