GEOMORPHOLOGICAL CONTROLS AFFECTING THE CREATION AND PRESERVATION OF A BURIED WETLAND ENVIRONMENT DURING THE PLEISTOCENE/HOLOCENE TRANSITION: A GEOARCHAEOLOGICAL PERSPECTIVE

Geoarchaeological investigations within the White River Valley in south-central Indiana revealed the controlling geomorphological factors that led to the formation and preservation of a buried wetland environment just prior to, and throughout the Younger Dryas. Coring transects within a local segment of the West Fork of the White River were used to analyze the subsurface sediments, identify paleosurfaces, and correlate the fluvial landforms along the White River. In one local river segment, late Wisconsin river meanders eroded into outwash terraces and left abandoned channels that infilled with organic debris after 13kBP. By 10kBP, local conditions created a local wetland/peat bog containing preserved organic matter that can be used for paleoenvironmental reconstructions during the Younger Dryas. Subsequently, a wet grassland/prairie developed after 10kBP and lasted until about 4kBP, after which the site was buried and preserved by mid-Holocene alluvium. Major river adjustments related to downcutting and entrenchment altered the extent of the mid-Holocene meander belt, limiting meandering and erosion through the site. Late Pleistocene and early Holocene meander scars at the site provide data important to archaeological site predictive modeling and to understanding where buried and preserved archaeological sites may occur during the Paleoindian (11.5-10kBP) and Early Archaic (10-8kBP) Periods.