Ultramafic Rocks of the Appalachian Piedmont
Base and precious metal stream-sediment geochemistry related to mafic-ultramafic bodies in the Alabama and adjacent Georgia Inner Piedmont
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Published:January 01, 1989
The Alabama and adjacent Georgia Inner Piedmont consists of a complex suite of metasedimentary and metavolcanic units that could have associated syndepositional hydrothermal systems. To evaluate the potential presence of such systems, a preliminary reconnaissance (silt and heavy minerals stream sediment) geochemical survey, consisting of 553 sites, was conducted. Silts were analyzed for Cu, Pb, and Zn; panned concentrates, for Au. Measured geochemical averages and the corresponding standard deviations for the samples are 16 ± 10 ppm Cu, 9 ± 6 ppm Pb, 37 ± 17 ppm Zn, 61 ± 29 ppm combined Cu-Pb-Zn, and 0.128 ± 0.751 ppm Au. Moderate correlation is shown among Cu, Pb, and Zn, but Au is statistically independent of the base metals.
Streams draining the well-documented mafic-ultramafic bodies of the Doss Mountain, Slaughters, and Easton areas exhibit low base and precious metal values. However, the generally similar areas of the Boyds Creek synform and the West Point mélange have anomalously high Cu-Pb-Zn and Au signatures that coincide locally with zones of tourmalinite, iron formation, gossan, and altered ultramafic bodies. These data suggest that hydrothermal systems were associated with the development of the ophiolitic suites of the Boyds Creek synform and nearby West Point mélange, and that stream-sediment geochemical anomalies within these areas may locally reflect mineralization related to such metal-rich systems.
- Alabama
- Appalachians
- base metals
- chemically precipitated rocks
- clastic sediments
- copper
- economic geology
- geochemical methods
- Georgia
- gold
- gossan
- heavy minerals
- iron formations
- lead
- metal ores
- metals
- metamorphic rocks
- metasedimentary rocks
- metavolcanic rocks
- mineral exploration
- mineralization
- North America
- ophiolite
- Piedmont
- precious metals
- sedimentary rocks
- sediments
- silt
- stream sediments
- United States
- zinc
- Easton
- Doss Mountain
- West Point Melange
- Boyds Creek Synform
- Slaughters