A Brief Distributional Assessment of Metavolcanic Artifacts and Sources
in the Long Cane District of the Sumter National Forest
or
Let There Be (Rhyo-) Light
Paper presented by Bobby Southerlin
at the Annual Conference of the Archaeological Society of South Carolina
Columbia, SC 2012
Abstract
The South Carolina Piedmont is a quartz-rich region, with quartz artifacts often accounting for over 90 percent of the lithic artifacts at Piedmont sites. Metavolcanic materials (rhyolite, dacite, etc.) typically come in at a distant second place in Piedmont lithic assemblages, and are often thought to have come from sources in the North Carolina Piedmont. Recent investigations in the Long Cane Ranger District of the Sumter National Forest suggest that exploitation of local metavolcanic sources have likely been underestimated. This paper presents a preliminary assessment of sites bearing metavolcanic artifacts in the Long Cane Ranger District, pointing out that while there may be movement of these materials from North Carolina to South Carolina, most of the metavolcanic artifacts recovered from sites in the South Carolina Piedmont may be from local sources.
Introduction
Over the last decade, ACC, Inc. has had the good fortune to work on a number of surveys in the Long Cane District of the Sumter National Forest (SNF). Through this experience, we have become familiar with many research topics in the region. This paper focuses on only one of the numerous research avenues for Native American sites: lithic material procurement and distribution.
Research Avenues
Geologic map of the Carolinas showing significant quarry areas
The Long Cane Ranger District is in the Piedmont physiographic province. This is a quartz-rich environment, with quartz averaging about 80 to 90 percent of all lithic artifacts from sites in the SNF (Benson 2006). However, anyone familiar with the area also knows that metavolcanic artifacts (i.e., rhyolite, dacite, etc.) are also common in the region. It is a common assumption that much of the rhyolite recovered in the South Carolina Piedmont is an exotic material. Only a decade or two ago, most rhyolite/metavolcanic artifacts (at least those of good quality) in South Carolina were off-handedly linked to the major sources in the Uwharries region of North Carolina.
Geologic map of Long Cane Ranger District showing quarry clusters
In recent years, Forest Service Archaeologist James Bates has brought to light a number of quarries in the Sumter National Forest which exhibit extensive labor in extracting knappable metavolcanic material for prehistoric tool production. These include the Little Mountain Creek Quarry (38SA64), the Roadside Quarry (38SA81/131), the Hillside Quarry (38SA132), and the Spring Branch Quarry (38SA133) in Saluda County. The Cyper Creek quarries (38ED675, 38ED683, 38ED740, and 38ED741) are in Edgefield County. Quarries in Saluda County are referred to as the Spring Branch Quarry Cluster. Those in Edgefield County are called the Cyper Creek Quarry Cluster.
I am trying to understand the distribution of metavolcanic materials present at archaeological sites in the Long Cane Ranger District of the SNF. First, I have examined the location and quantification of metavolcanic material (using count, not weight) using data from projects we have conducted and similar projects in the vicinity.
Lithographic Map of Long Cane Ranger District
Second, I am using the geologic and archaeological data to identify “hot spots” linked to suspected source areas. This approach has the potential to identify unknown source areas in the vicinity. The simple premise is that greater quantities of material will be located closer to source areas.
Data
Forest Service Archaeologist James Bates was the first to identify and document metavolcanic quarries in the Long Cane Ranger District, recording the first such site in 1988 (Little Mountain Creek quarry). I have incorporated his data with that gathered by ACC during the course of several archaeological surveys conducted in the district (O’Neal et al. 2010, 2011, and 2012; Reid et al. 2010). In addition, data from modern surveys with similar field methods conducted in the project vicinity were incorporated into the research database (Benson 2007, 2010; Keith and Keith 2002; Keith et al. 2007), as was data from James Bates’s and Daniel Elliott’s work.
Sample of site with metavolcanic artifacts in the Long Cane Ranger District
The database consists of all sites with metavolcanic artifacts (n=252) in the targeted survey areas; the total area surveyed in these studies is about 18,000 acres. These sites were then ranked based on the quantity of “metavolcanic” artifacts identified, and these rankings were plotted on a series of geologic and Forest Service maps.
The area of interest is part of the Carolina Slate Belt. Feiss et al. (1991) describe the “thick sequences of undifferentiated felsic and mafic metavolcanic rocks” in the Carolina Slate Belt. The Carolina Slate Belt is referred to as the Uwharrie Formation in North Carolina, the Persimmon Fork Formation in central South Carolina, and the Little River Series along the South Carolina-Georgia border. These formations are the result of similar volcanic episodes. The mafic to felsic rocks range from basalt to andesite to dacite to rhyolite.
Scott Jones (2007) visited sites at both the Spring Branch and Cyper Creek quarries and examined the natural and cultural attributes of the materials:
“In general, raw material occurs in rectilinear blocky pieces. Fractures or jointing present in some material results in rhomboid or triangular cross-section, the joints intersecting at an angle of about 60 degrees. Weathered surfaces of some pieces exhibit banding. On fresh surfaces, banding is often faint or absent. Although on some specimens banding corresponds to qualitative differences.”
Flaking on tested pieces “is executed in a way consistent with bifacial production. This suggests that prehistoric quarrying was an intensive and highly selective process geared towards the procurement of specific grades of raw material.”
Jones (2007) identified three broad categories of material:
1. Dark, almost cherty material with slightly grainy surface. Thin flakes have translucent edges. This material seems to have been the most favored.
2. Light blue-gray to tan grainy material. Has abundant small pyrite crystals
3. Dull purplish to pale gray grainy opaque material – poorer grades look like concrete.
Spring Branch Quarry Cluster
Quarry debris exposed along the roadside at site 38SA131
The Spring Branch Quarry Cluster is in western Saluda County. These sites were recorded by Bates and a number of them were revisited by ACC during a recent survey. All of these sites have large pits that were excavated into the ground and bedrock to expose and extract desirable material. Large dense (diabase?) hammer stones are often associated with these pits.
Mittwede (1988) has referred to the metavolcanic material in extreme western Saluda County as Spring Branch Rhyolite. This is generally a blue-gray fine grained (aphanitic) material. The rhyolite formation that Mittwede discusses is bordered on the west by hydrothermally altered rhyolite rocks (alv) and felsic and intermediate metavolcanic rocks of the Persimmon Fork Formation. To the east is metamudstone and metasiltstone (arg) of the Richtex Formation; a Mesozoic diabase dike (db) is shown within this formation.
Quarry debris at site 38SA133
Cyper Creek Quarry Cluster
This cluster consists of four to six sites. At least one site has extraction pits. Very dense lithic debris litters the creek and its associated side slope. The majority of the Cyper Creek rhyolite appears to be banded. Intensive survey conducted by Benson (2007) provides details on these sites.
Discussion and Future Efforts
Recent investigations in the Long Cane Ranger District of the Sumter National Forest suggest that exploitation of local metavolcanic sources have been underestimated. Geologic data reflects relatively large areas with potential for extraction of metavolcanic raw materials by Native Americans. Archaeological data presented in this paper indicates that intensive quarrying of metavolcanic materials occurred in the Long Cane Ranger District. While there may have been movement of these materials from North Carolina to South Carolina, most of the metavolcanic artifacts recovered from sites in the South Carolina Piedmont are likely from local sources. Below are a few lines of inquiry for future research.
Metavolcanic projectile points from the Long Cane Ranger District
Consistent terminology and material identification
One of the problems associated with this type of research is that the terminology and material identification can vary from researcher to researcher. This region geologically should be rich in both metavolcanic and metasedimentary (mudstone, siltstone, argillite), but the metasedimentary material is infrequently identified. Is it being missed or mis-classified as metavolcanic? Macroscopically, it can be very difficult to accurately identify these different lithic materials, particularly if they are highly weathered.
Assessment of central and eastern region of Carolina Slate Belt in South Carolina
The Carolina Slate Belt is a large area spanning eastern Georgia through central North Carolina. The abundance of surveys in the Long Cane district is presenting a picture of the western portion of the slate belt; however, central and eastern South Carolina suffer from a lack of large-scale surveys. Based on our geologic assessment, we would expect to find metavolcanic quarries across the state unless there is quality variability along the slate belt. Furthermore, this paper only presents data on a small portion of the Long Cane Ranger District and much inquiry remains to be done here.
Artifact Sourcing
One area of confusion is identifying the source of these materials. We have been dealing with assumptions that high quality metavolcanic material (rhyolite) in the Uwharries in North Carolina have been working their way into western South Carolina. Recent research by Mark Brooks and Chris Moore and Al Goodyear and Chris Young are beginning to address this issue through the use of petrographic analyses. But there is a long way to go.
Chronological Assessment
Research in the region indicates a strong association between use of metavolcanic lithic material and Late Archaic sites. Diagnostic artifacts from quarry sites tend to be Late Archaic (James Bates 2010, personal communication; Benson 2006; O’Neal et al. 2010b; Sassaman 2006). Therefore, relatively high proportions of metavolcanic material may be an indicator of a Late Archaic association whether diagnostics are found or not. It may be that any long distance movement of high grade rhyolite from North Carolina into South Carolina is more likely linked to the Paleoindian and Early Archaic periods, with their presumed more mobile settlement patterns.
