Northeastern Section (39th Annual) and Southeastern Section (53rd Annual) Joint Meeting (March 25–27, 2004)

Paper No. 3
Presentation Time: 8:00 AM-12:00 PM

A COMPARISON OF GOLD EXPLORATION TECHNIQUES AND NEW GOLD DISCOVERIES IN DEEPLY WEATHERED ENVIRONMENTS OF THE SOUTHEASTERN UNITED STATES AND SURINAME


LAPOINT, Dennis J., Appalachian Rscs, LLC, P.O. Box 3810, Chapel Hill, NC 27515, dlapoint@mindspring.com

In 2002, a new gold discovery was made in eastern Suriname in a region of no prior bedrock exploration using many of the methods modified from gold exploration in the southeastern US that lead to two new gold discoveries, Buzzard and Rattlesnake, in the mid 1990's.

The Suriname discovery is within an upland rainforest environment that is being disturbed by on going small-scale mining. This mining is not legal and is destructive to the environment, but is important to the local and national economy. The social and environmental setting is similar to descriptions of the first gold rush in the Carolina’s in the 1820's.

Both regions have deep weathering with minimal surface exposures. Saprolitic weathering extends to depths of 80 to 100 meters in Suriname versus 10 to 20 meters in the southeast. Mapping is limited to saprolitic exposures from mine workings and creeks. Geologists trained in exploration from the southeast US demonstrate good interpretative skills in mapping these weathered rocks.

Geophysics, in particular magnetic surveys, are useful to define lithologies, alteration and structural trends, but geochemical methods play the most critical exploration role. Panning, augering, trenching and saprolitic drilling techniques modified from the southeast are applied to Suriname. Panning has been the most useful tool for reconnaissance exploration in the SE. In Suriname because of on going mining and disruption of drainages, it is less useful. In Suriname, bucket auger sampling to a depth of 2 meters along ridgecrests to locate and define a gold trend of over 12 km in length and up to 1 km wide. Sampling ridgecrests at this sample depth better defines primary gold targets instead of chemically and mechanically transported gold targets. Multi-element chemistry is useful, but gold is still the best indicator of gold.

To locate drill sites for diamond core drilling and to define a gold resource, saprolite core drilling, trenching, deep auger sampling into saprolite on a grid and mapping and sampling small scale mining sites are used. In both Suriname and North and South Carolina, new discoveries have been made with these exploration methods.