Earlier this year, lead archaeologist, Dr. Mike Johnson, wrote up a progress report of the archaeological work that has been done at the Mill to date. We’re excited to present the final section of the paper, Part 3 of his “Thoroughfare Gap Archaeology News” below (Click HERE for Part 1 and Click HERE for Part 2).
The rest of this newsletter will focus on the prehistoric aspects of Thoroughfare Gap archeology, which is Johnson’s research interest. However, Johnson will continue to provide preliminary assessments of historic results as appropriate.
Currently, the excavation levels are below the historic artifact zone, with a possible exception of a disturbance in the northeast corner of Square 2 (N960E3476). No evidence of a cellar or historic pits have been detected in the three test squares. As a result it is likely that any prehistoric occupations have not been disturbed by historic period activity.
This is supported by a discovery on September 3 that what was originally thought to be evidence of a shallow relic stream bed from when Broad Run was running across the feature, many thousands of years ago, was actually a prehistoric artifact. Figure 8 shows the large, water rolled boulder after it was cleaned off at the bottom of level 105 in Square 3. The inset image shows that the boulder was discolored from burning and it has a battered area (arrow) that was from using it as an anvil stone, probably from splitting high quality stream cobbles. Level 105 also produced the highest concentration of worked quartz artifacts yet recovered from any excavation level on the site. Figure 9 shows a clear quartz biface fragment and a large quartz unifacial core fragment. These artifacts located on the same level; in an isolated context, and in proximity to an “immovable” object, the anvil, strongly suggest that the excavation has encountered a relatively undisturbed surface.
Figure 8. Plan view of Sq. 3, level 105 with large anvil stone.
Figure 9. Clear quartz biface (1) and quartz unifacial quartz core fragment (2) from Sq. 3, level 105.
Recently, two possible Middle Archaic, Morrow Mountain-like points were recovered from the other two squares (Figure 10). Both were laying relatively flat, indicating minor displacement, and were at approximately the same level. Morrow Mountain points date to approximately 7,000 to 7,500 years ago (B.P). It is possible that the two points could be Late Archaic (4,500-3,700 B.P.), Savannah River knife/saw-like tools. However, the use of quartz in Savannah River points is rare. On the other hand, hornfels was commonly used in the Savannah River period. The unusually high number of meta-volcanic artifacts from both squares suggests the Morrow Mountain age.
Figure 10. Hornfels Morrow Mountain-like point (1) from Sq. 1, Level 105, and quartz Morrow Mountain point (2) from Sq. 2, Level 104.
As stated above, the meta-volcanic stone occurring on this site probably comes from geological formations located south of the James River. Major prehistoric meta-volcanic quarries occurred at Morrow Mountain in central North Carolina, where the stone was commonly used during that cultural period. Unlike Savannah River artifacts, Morrow Mountain artifacts are uncommon in Northern Virginia, which makes the resolution of this question important to the major prehistoric research question about the use of water gaps as places where people came periodically from great distances to meet.
These are preliminary evaluations of recent data, only just uncovered in the last few weeks. With the recent discoveries, especially of potentially minor disturbance to the prehistoric components, it is possible that the site has good stratigraphic integrity. That would make the site’s prehistoric components extremely rare in an interior upland context. Most stratified sites have been found along major waterways, such as rivers and estuaries, where large volumes of loose sediment/sand are available for both water and wind transport.