Paper No. 4
Presentation Time: 9:00 AM-6:00 PM

UTILIZING DOWN TO EARTH FIELD MAPPING TECHNIQUES TO DECIPHER THE STRATIGRAPHY AND STRUCTURE OF THE RIDGEWAY GOLD DEPOSITS, SC (Invited Presentation)


GILLON, Kenneth A., Haile Gold Mine, Inc, 7283 Haile Gold Mine Road, Kershaw, SC 29067, kgillon@romarco.com

Rio Tinto’s Kennecott Ridgeway Gold Mine (KRGM), located in the Carolina Terrane (CT) of South Carolina, operated from Dec. 1988 through Nov.1999. The KRGM mined low grade disseminated gold ore from the North and South pits, located 1 mile apart, and poured 1.44mm oz of Au and 850k oz of Ag.

A team of KRGM geologists and technicians labored over 6 years in the field to unravel the complex geology of the these large, low grade Au (~1g/t) ore deposits prior to the mine’s opening in 1988. The deposits were weathered to depths ranging from surface to nearly 100 feet, making it difficult to decipher stratigraphic and structural aspects. The solution to this problem was the excavation and detailed mapping, sampling, photographing of thousands of feet of trenches, and the integration of these data with several hundred thousand feet of core and reverse circulation drillhole data. The field tools used include sharpened garden hoes, machetes, knives, drafting mylar, polymerized lead pencils, magic markers, spray paint, brooms, and pressure washers. Such work led to the development of a cohesive stratigraphy and ore deposit model that served well throughout the subsequent 11 years of open pit mining. Periodic visits to the mine to observe its progress and compare one’s initial understanding of the deposits based on surface work, with those at depth (ultimately to 450 feet of depth in both N and S pits) was a geologist’s dream, and further enhanced understanding of the evolution of this portion of the CT. This poster provides pictorial and map examples of the field and lab techniques utilized during the exploration and mining phase of these deposits. The purpose of this poster is to acquaint geologists with these techniques and demonstrate that field geologic relationships can be deciphered here in the southeast USA Appalachians in spite of the deep weathering, cover vegetation and critters.