THE ARCHAEOLOGICAL GEOLOGY OF A STRATIGRAPHICALLY COMPLEX HOLOCENE SEQUENCE IN THE LOWER OHIO RIVER VALLEY

Extensive geoarchaeological studies a part of the Caesars Archaeological Project near Louisville, Kentucky in the Ohio River flood plain detailed a complex geomorphic and archaeological Holocene sequence. Landforms and associated alluvial and colluvial deposits contained buried archaeological remains that range from 10K to 2K RCYBP based on more than 70 radiocarbon ages.

Sediment units in the project locality encompass a wide range of geomorphic systems, including Ohio River lateral accretion/overbank units, low and higher order tributary stream deposits, and colluvial material that are inset or commingle in a complex fashion. Soil-geomorphic and sedimentological analyses were used to discriminate these landform sediment assemblages. Early and late Holocene units differ in their textural, bedding, and soil weathering properties.

Archaic and Woodland occupations are stratified in these sediment packages to a depth of up to 5 meters. Cultural deposits are differentially affected by various geomorphic and soil processes. Especially in the early Holocene units prehistoric occupations are influenced by processes associated with high energy tributary stream channels that interdigitate with lower energy lateral accretion and overbank deposits laid down by the Ohio River as it formed a point bar and subsequent levee. At the same time Ohio River bar/levee formation resulted in a complex set of sloping paleotopographic surfaces that Archaic hunter-gatherers occupied. The stratigraphic distribution of artifacts, features, and radiocarbon ages are a key to identifying and tracing these surfaces and understanding their stratigraphic relationship.