Alluvial stratigraphy and geoarchaeology in the Big Fork River Valley, Minnesota: Human response to Late Holocene environmental change

The Late Quaternary geomorphology and stratigraphy of the Big Fork River valley, within the Rainy River basin of northern Minnesota, reveals evidence of prehistoric human interaction with late Holocene riverine environments. By 11 000 ¹⁴C BP, deglaciation made the region inhabitable by human groups using Clovis artefacts. Human habitation would also have been possible during the Moorhead low-water stage of glacial Lake Agassiz, starting at 10 500 ¹⁴C BP. Near its confluence with the Rainy River, the valley floor of the Big Fork valley consists of a floodplain complex and two terraces. The multi-component stratified Hannaford site is situated within the active floodplain. Overbank deposits contain artefacts in primary context, whereas artefacts within the point bar deposits are in secondary archaeological context; these deposits are associated with changing alluvial settings as the river moved eastward. Aggradation of the valley fill beneath the lowest surface (T₀, floodplain complex) began by 3000 years ago and is associated with human activities focused on seasonal fishing and the use of riparian resources from 1300 to 650 ¹⁴C BP.