Arnolds Valley jasper, 44RB0323, Rockbridge County, Virginia.
Arnolds Valley jasper, Rockbridge County, Virginia.
Samples collected along East Fork Elk Creek (site 44RB0191) and from site 44RB0323, Rockbridge County, Virginia.
Arnolds Valley jasper is a jasper breccia and was formed along a large thrust fault that moved the Erwin quartzite onto the later carbonate formations of the Shenandoah Valley floor. The jasper breccia contains distinctive pieces of quartzite that appear as phenocrysts in the matrix of jasper. The material has been subjected to a high degree of metamorphosis and the quartzite phenocrysts, while distinctive to sight, have lost their structure and breaks across the grain. Stringers of chalcedony are found within the breccia, probably a result of secondary replacement from a silicate charged groundwater flow. While this jasper occurs in shades of yellow and red, analysis indicated that most of the red colored material are pot lidded, an indication of heat treatment.
Although widely used in Rockbridge County, the distribution of this material is unknown.
The Arnolds Valley jasper breccia was used by Native Americans from the Early Archaic through Late Woodland periods.
Prepared By Tolley 1999
Updated October 22, 2016