Brook Run, located in the piedmont region of northern Virginia in a grove of cedar trees near the Rapidan River, contains important evidence of rock quarrying by some of the earliest human residents of the region. The Brook Run site consists of at least two hearths dated between 10,000 and 9,400 years before the present, perched on either side of a vertical vein of high quality jasper rock.
Jasper is a crypto-crystalline silica rock type (like chert and quartz), with a high iron content giving it a distinctive reddish-brown coloration. The jasper was forced upward through the siltstone bedrock by volcanic action hundreds of thousands of years before. It was sought by the choosy, nomadic Early Archaic people, because of its waxy luster and fine texture, making jasper easy to work into sharp stone tools such as projectile points, scrapers, or knives.
Mining Jasper at Brook Run
Beginning about 10,000 years ago, people came to work the two-foot-wide jasper vein, using stone tools to bang out nodules, some as large as bowling balls. The nodules were broken into smaller pieces and then the pieces were taken away to living camps, where stone tools were made. For the next 600 years, the two shaft pits into the jasper seam were excavated deeper and deeper, until the mine was some fourteen feet below what is now the surface and only 18 inches wide. At the bottom of the seam archaeologists found six digging tools and a hammer stone.
The site was a complete surprise to the archaeologists, who found it in 1996 while digging small test holes along Route 3 when they stumbled on an abundance of jasper flakes where there was no outcrop to be seen. Since the occupation at Brook Run, the detritus of the mining activities and natural erosion has filled in the mine and covered the area up to six feet in thickness. The archaeologists were at a loss to explain the presence of jasper at the site until they had dug more than 14 feet down, and found what was left of the quarry.
In addition to the hearths, Early Archaic Kirk points of rhyolite and quartz, dated between 10,750-8000 years before the present.
As many as 700,000 stone artifacts have been recovered from the Brook Run site, weighing nearly two tons; the few tools recovered were biface fragments, blades, retouched flakes, hammerstones and anvils.
Monaghan, G. William, Daniel R. Hayes, S.I. Dworkin, and Eric Voigt. 2004. Geoarchaeology of the Brook Run site (44CU122): an Early Archaic jasper quarry in Virginia, USA. Journal of Archaeological Science 31 (2004) 1083-1092
Thanks to Eric Voigt for information about Brook Run.