Over the past couple of weeks the Castle Museum Archaeology Team has once again found itself waist-deep in the poison ivy fields of the Shiawassee National Wildlife Refuge. Throw in some nearly impossible-to-screen clay soils, clouds of mosquitoes, and an occasional drenching downpour and you’ve got all the makings of a spa-like Summer retreat! Conditions may be difficult, but we get to do fieldwork, so no complaints here!
We have been shovel-testing between two previously documented archaeological sites, 20SA315 and 20SA214, near the Shiawassee River. During the Spring of 2014, we conducted a surface survey of a portion of 20SA315. That work is briefly discussed here. 20SA315 is multi-component but appears to date predominately from the Late Woodland time period. A guess, based on highly fragmented ceramics, puts a likely date in the AD 1000-1200 range. 20SA214 is a site we began monitoring in 1999. It, too, is a multi-component site and a number of biface types spanning the Late Archaic through the Late Woodland have been recovered. It no doubt temporally overlaps 20SA315, but the majority of the occupation debris appears to be a bit earlier – likely Middle to early Late Woodland.
Our current project has two goals. The first is to test the area between the known distribution of artifacts at 20SA214 and 20SA315 to determine site boundaries. The second is to test for the presence of intact archaeological deposits below the plowzone. So far our shovel-test pits (STPs) have revealed a very thin scatter of prehistoric artifacts in the area between the two sites. Three of our eight 50cm X 50cm STPs have yielded single bayport chert flakes. One of the three also contained a few possible quartzite flakes and/or FCR. So, it looks like, while 20SA315 and 20SA214 have definite artifact concentrations, the area between them is not completely sterile.
The stratigraphy has been fairly consistent in each of the STPs. A dark, 25-30cm, silty clay plowzone is followed by a mottled, but mostly dark, 10-20cm thick zone of silty clay and clay. This is followed by a mottled, progressively lighter-colored zone of clay and silty clay. In a couple of the STPs small pockets (<3-4cm) of silty fine sand are intermixed with the clay in the lower mottled zone. In STP 6, the water table was encountered at about the 70 cm level. The other STPs were not dug deeper than 60 cm. Artifacts were found in the plowzone in STPs 6 and 8 and below the plowzone in STPs 3 and 6. Although no distinct former land surfaces are visible in the sediment profiles, the presence of artifacts below the plowzone leaves open the possibility for stratified archaeological deposits and intact features. The heavy mottling is likely due to bioturbation (mixing caused by roots and animal burrows).