Silicified Fault Breccia, Drusy Quartz and Banded Chalcedony
Greenville County, South Carolina
February 19, 2005
By Mike Streeter

From conversations over the years with different rockhounds, I was aware that banded chalcedony and quartz could be found in a wide area within southern Henderson Co., NC and northern Greenville Co., SC. I have been shown rock specimens composed of chert and quartz in what appeared to be some sort of breccia. I was even told about a certain spot where these materials could be found along a creek just south of the NC/SC border. Since I am not a cutter, I am generally not much for chert hunting, so I never followed up on the information . . . until recently . . .

As a geologist, I often employ published geologic maps to prospect for potential rockhounding sites. Such was the case after I recently received a map produced by the United States Geological Survey titled, "Geologic map of the Greenville 1-degree X 2-degree quadrangle, Georgia, South Carolina and North Carolina" by Arthur E. Nelson, J. Wright Horton, Jr., and James W. Clarke. I was studying the map and discovered a series of linear faults in the vicinity of Lake Summit. One fault runs in a southwesterly direction from near Saluda to Greenville County, South Carolina. Associated with the fault is a silicified breccia. The description of the rock from the map key is as follows:

"Silicified Breccia - Cohesive, silicified fault breccia, composed mostly of fine-grained quartz. Vugs lined with drusy quartz crystals are common. Occurs as tabular, steeply dipping bodies."

The proverbial light bulb turned on over my head after reading the description. I took the old and new information with me to the field to see if I could track the fault and locate the associated silicified breccia.

I started near Saluda, NC where I found a trace of the fault near the North Pacolet River. There didn't seem to be any decent rock at this location so I proceeded on. I attempted to trace the fault in a southwesterly direction but was frustrated by private property and the Greenville Watershed where it is illegal to get out of your car unless in an emergency.

Late in the day, I finally found an area in northern Greenville County where silicified fault breccia was plentiful along a creek. I even found an area that appeared to have been frequented by rockhounds, as the creek bank had obviously been disturbed and there were tons of broken rock scattered about. I banged on a few loose rocks and managed to recover some decent specimens with drusy quartz and banded chalcedony in a silicified breccia. The following pictures show the type of material that I dragged home from the site.

Click on each picture below to enlarge

Being an "ist" by no means ensures rockhounding success, but sometimes it helps!