Stream Sediment Samples from 1070s Re-analyzed to establish new baseline

The Wyoming State Geological Survey (WSGS) released geochemical data, as Open File Report 2020-7, from a reanalysis of archived stream-sediment samples originally collected under a federal uranium exploration program. The new data will help to establish modern baseline geochemistry for future studies of mineral systems and deposits across Wyoming.

The uninterpreted “raw” data are available as received from the laboratory, providing geologists and the mineral industry with the opportunity to use the data for research and exploration purposes.

The geochemical results are provided as Excel spreadsheets that accompany a short report detailing the sampling methodology, available as a free download from the WSGS website.

The original stream-sediment samples were collected in the 1970s under the National Uranium Resource Evaluation (NURE) program, established by the U.S. Atomic Energy Commission to identify uranium resources throughout the United States. The program focused on the collection and subsequent geochemical analyses of these samples for uranium as well as 47 other elements. More than 18,000 samples were collected in Wyoming, analyzed at multiple laboratories, and stored at the U.S. Geological Survey’s National Geochemical Sample Archive.

In 2019, WSGS Open File Report 2019-2 used the original 1970s data to model the regional distribution of known and potential mineralization across Wyoming, with results summarized spatially in the WSGS’s online Mines and Minerals Map.

However, Open File Report 2019-2 highlighted the limitations of the historic NURE dataset, and subsequently the Wyoming Legislature appropriated funding to reanalyze the samples using modern analytical techniques with the intention of providing updated data for research into critical and economic minerals.

“As the United States searches for domestic sources of critical and strategic minerals, Wyoming has an opportunity to explore for and potentially develop new resources,” says Dr. Erin Campbell, state geologist and director of the WSGS. “Funding from the state legislature has allowed us to further advance our interpretation of the distribution of those elements and minerals across the state.”

Funding allowed for analyses of 159 archived samples, which were chosen using a variety of criteria focused on high concentrations of critical and economic elements, such as uranium, vanadium, titanium, platinum group elements, and rare earth elements.

“The samples were reanalyzed using modern techniques performed at a single laboratory, allowing for standardized results that can be compared across the dataset,” says David Lucke, manager of the WSGS technical analysis and data division.

This project was a cooperative effort with the U.S. Geological Survey, who is also working with the mining industry to reprocess samples from other western states.

“Although this new dataset will allow researchers to further investigate areas of anomalous elemental values, the data will be most useful as a way to understand the reliability of the original NURE dataset, which is much larger and more statistically robust,” says Lucke.

More information about critical minerals, including critical minerals of highest potential in Wyoming, is available on the WSGS website.