The South Branch or Shawnee-Oldfields site (18AG20) describes a pair of Late Woodland villages located on the rich alluvial floodplain on a low terrace of the Potomac River.  The site is located approximately half a mile downstream of the mouth of the South Branch.

Archaeological Investigations

Site 18AG20 is listed on the National Register of Historic Places.  The site has been subject to episodic surface collecting.  Tested in 2009/201 during a Phase I survey by the Louis Berger Group, Inc.  Long thought to be the site of an eighteenth-century Shawnee occupation, the Berger Groups’s excavation, assessment of surface finds and radiocarbon dates confirm a Keyser (AD 1450-1500) occupation at the villages. 

Two auger borings revealed approximately 1.5 feet of modern alluvium over an historic plowzone.  A weak B-horizon and a buried A-horizon were also identified over deeply bedded Pleistocene gravels.

Three lines of shovel test pits at 50-foot intervals were dug across the entire site from northwest to southeast in transects spaced 100 feet apart.  91 of 103 STP’s were positive.  Recovered artifacts include debitage, small triangular points, and prehistoric pottery.  A minimum of two ceramic types were identified.  Both are cordmarked, relatively thin, and probably Late Woodland in origin.  Dark rock and shell tempers are represented.  The shell-tempered ceramic type appears to be Keyser ware (AD 1400-1550).  The rock-tempered pottery suggests earlier ceramic types.

A series of test units were excavated within areas identified as being central to both villages.  Four test units excavated with the East Village identified partially stratified deposits, a predominance of Keyser ceramics overlying older rock-tempered wares.  Five test units within the West village were located near STP’s that produced high artifact counts.  A Late Woodland pit (Feature 1) was identified within Unit 10, which was placed with help from a magnetometer survey.  Feature 1 was roughly circular, 3.5 feet in diameter, and 0.6 to 0.9 feet below the plowzone.  A rich array of artifacts was recovered, including daub, antler, 234 pieces of chert debitage, FCR, three triangular projectile points, and bone (deer, turtle).

Archeobotanical Studies

Two hand-collected carbon samples and a six liter flotation sample were collected during the Berger Group’s excavation of Feature 1 and from non-feature cultural contexts.  The hand-collected carbon samples totaled 24.81 grams (inclusive of sediment) and produced 10.11 grams of charcoal measuring greater than or equal to 2mm in diameter.  Wood charcoal and nutshells were recovered.  Wood fragments totaled 126 fragments weighing 8.71 grams.  Of this total, 21 fragments (a maximum of 20 fragments per sample) were randomly selected for identification.    Hickory was the most abundant wood type identified, followed by white oak, with pine and red oak.  Thick-walled hickory nutshells (eight fragments weighing 1.4 grams) were recovered from the Feature 1 sample.

The flotation sample yielded 5.355 grams of carbonized plant macro-remains.  A variety of economically-important plants were represented in the sample.  Wood charcoal (dominated by white oak and hickory species), thick-walled hickory nutshell, maize (cupule and cupule fragments), sumac seed and amorphous carbon were identified.


Bedell, John, Jason Shellenhamer, and Charles LeeDecker
2011  Archaeological Identification and Evaluation Study, Section III, Chesapeake & Ohio Canal, National Historical Park.  The Louis Berger Group, Inc., for the National Park Service.
McKnight, Justine
2010 Report on the Analysis of Flotation-recovered and Hand-collected Archeobotanical Remains from Three
Sites (18AG19, 1 8AG20, and 18AG262), C&O Canal Park, Allegeny County, Maryland. Appendix E in
Archaeological Identification and Evaluation Study, Section III, Chesapeake & Ohio Canal,
National Historical Park.
Volume III. The Louis Berger Group, Inc., for the National Park Service.

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