North-Central Section - 49th Annual Meeting (19-20 May 2015)

Paper No. 6
Presentation Time: 10:00 AM

AN UNUSUAL OCCURRENCE OF MINOR PRECIOUS METALS IN BREATHITT COUNTY, KENTUCKY


BARRETT, Heather1, KREKELER, Mark P.S.2, CLARK, Cameron2, FLETT, Lonnie2 and ARMENTROUT, David2, (1)Geology & Environmental Earth Science, Miami University, 114 Shideler Hall, Oxford, OH 45056, (2)Geology & Environmental Earth Science, Miami University-Hamilton, 1601 University Blvd., Hamilton, OH 45011, barretha@miamioh.edu

Breathitt County, Kentucky is an economically disadvantaged region that has a history of resource extraction. The region is dominated by the Pennsylvanian Breathitt sandstone group which represents a fluvial - deltaic - marine system with extensive coal deposits. Mineralogical investigations of these sandstones in the region indicate that muscovite, biotite, kyanite, and zircon are common detrital grain constituents. Little work has been done in the area in the context of mineral exploration as the geology does not fit classical exploration models for numerous mineral resources. The Wyatt property located in Breathitt County has a history of multiple uses including minor coal mining, oil and gas production and logging. Family history indicates that valuable metals were found on the property in the late 1800’s. Recent investigations of stream sediments by bulk chemical analyses and scanning electron microscopy indicate that silver is common, occurring at concentrations of 0.4 to 1.7 ppm, and a as flake. Based on refined family information a site was identified as a potential source of precious metal. SEM data from sediment from new limited exploration pits have found silver flake in soils. This silver flake is similar in texture to that observed from previous work. SEM work also found a single occurrence of a euhedral gold crystal that is 35 micrometers in diameter. The texture of this crystal suggests that the gold crystallized locally. A possible explanation for the origin of the silver and gold is provenance ultimately from central Virginia where rocks from the central gold belt were eroded and then deposited during the Pennsylvanian. Minor detrital silver and gold in sandstones may be remobilized by the organic materials in either deep geologic time or by soil processes similar to suspected authigenic gold in Venezuela and Africa. This work justifies future detailed provenance studies and geochemical exploration of the area.