Bringing Science to Bear at the Cinnabar Mine

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At USGS, although the rocks we study are millions of years old, our scientific methods are cutting edge! Here's just one example of how we use creative problem-solving to help crystalize a solution to a complex issue.

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JoAnn Holloway, biogeochemist with the USGS Mineral Resources Program, explains how interdisciplinary science can help better inform the conditions of a complex ecosystem. Videographer: Jacob Massey, USGS (Public domain.)

Mining activity in the 19th to 20th century was one of the drivers of western expansion in the United States. However, as those mines played out and miners moved on, the mines themselves remained. In fact, the Bureau of Land Management estimates up to a half-million abandoned mine lands exist in the United States.  Of these, the Government Accountability Office estimates 131,000 are abandoned hardrock, or base metal (e.g., gold, silver, copper) mines in the western United States, with approximately 33,000 sites resulting in the degradation of environmental quality. 

Few of these sites have been evaluated to determine potential for continued environmental impacts, or exacerbated environmental impacts resulting from shifting land-use, including urbanization, road construction, or a resurgence in mining.  Evaluating environmental impacts of abandoned hardrock mines is most effective if conducted using teams of multi-disciplinary scientists, including hydrologists, geologists, geochemists, and ecologists. 

Image shows remnants of an abandoned mine in a hilly, forested area
Mine tailings from the abandoned Cinnabar Mine in Idaho.(Credit: JoAnn Holloway, USGS. Public domain.)

The East Fork South Fork Salmon River watershed in central Idaho is at the headwaters of the South Fork Salmon River, a spawning area for Chinook Salmon, and part of Nez Perce Tribe ceded lands.  Cinnabar Creek, a tributary to this stream, flows through the Cinnabar mine site, an inactive mercury mining site.  This site is being evaluated for remediation by the U.S. EPA due to elevated metal concentrations, including  mercury and arsenic, associated with mine tailings, sediment and water. 

An interdisciplinary team of U.S. Geological Survey scientists are evaluating the Cinnabar mine site and the East Fork South Fork Salmon River watershed to quantify environmental impacts.  A geological background for mercury and arsenic has been established using rock, stream sediment and water chemistry outside of the historical mining area.  Transportation of rock from mine tailings to downstream sediments s being evaluated using a combination of geochemistry and mercury isotopes.  Mercury and arsenic transfer from the stream to the biota is being evaluated by ecologists who study insects, spiders and fish. 

Image shows a wide forested landscape with mountains in the distance
The Cinnabar Creek watershed in Idaho. The region is an important spawning area for Chinook Salmon, and part of Nez Perce Tribe ceded lands.(Credit: JoAnn Holloway, USGS. Public domain.)

This work is being conducted in cooperation with the Nez Perce Tribal Fisheries Resources Program, the U.S.D.A. Payette National Forest, the U.S. EPA, with site access being provided by Midas Gold Corporation.  Our data and our interpretations are being used to help inform a better-informed effort towards remediating the Cinnabar Mine site, with the goal of improving the quality of this salmon fishery. 

Learn more about this project here, and learn more about other USGS minerals research in the Yellowpine area here.