GEOARCHAEOLOGICAL INVESTIGATION WITHIN THE CONNECTICUT RIVER VALLEY BELOW TURNERS FALLS: A GEOMORPHIC RECONSTRUCTION OF THE POST-GLACIAL ALLUVIAL HISTORY OF THE VALLEY

The Tuners Falls Gorge region of the Connecticut River Valley contains extensive late Pleistocene and Holocene deposits as well as an abundance of Pre-Contact archaeological sites spanning the last 12,000 years before present. This paper presents a new study of the geomorphological formation of the post-glacial alluvial landforms in the Turners Falls Gorge region of the Connecticut River Valley using soil and geomorphologic information combined with dating based on radiocarbon samples and temporally diagnostic, cultural artifacts. Previous geoarchaeological studies have focused on landform development in relation to the location of archaeological sites just above the falls; this study focuses on landform and sites below the falls. A synthesis of the modern study with past studies is presented to provide a model of landscape development which can be used to help predict the location and age of archaeological sites both on and buried below the landscape in the region.

The study area focuses on an archaeological site on the west bank of the Connecticut River, in Greenfield, Massachusetts. The study area contains six geomorphic surfaces, ranging in age from the late Pleistocene period to the late Holocene period, which have been formally named in previous publications on the geomorphology the Connecticut River. These are, in order from oldest to youngest, the Lilly Pond Terrace, the High Terrace, Intermediate Terrace, Low Terrace, and Low Floodplain. Similar, correlative, geomorphic landforms to the ones at the study area are seen just upstream in the Riverside Archaeological District, above the Turners Falls.

Pre-Contact Native American archaeological cultural deposits were identified on both the Intermediate and Low Terraces. Both terraces formed as floodplains that experienced multiple periods of rapid sedimentation, followed by periods of landscape stability, during which soils formed. These periods of stability allowed for Native American groups to occupy the landforms while they were still forming. A well-stratified archaeological record of these occupations developed on the Low Terrace, to a depth of approximately four meters below surface. Unlike the Low Terrace, the older Intermediate Terrace did not contain deeply buried cultural deposits, which were instead located at or near to the modern landform surface.