UNCOVERING THE CHARACTERISTICS OF THE SALT RIVER PALEO-LAKE IN NORTH-CENTRAL KENTUCKY

Glacial lake deposits in Kentucky are an important archive of the state’s environmental history that would benefit from more extensive study in addition to surficial mapping efforts. The glacial history of Kentucky along the Ohio River has been expanded in both northern and western Kentucky, but for the land in between, there are numerous unanswered questions. Geological mapping of bedrock in central Kentucky during the 1960s and 1970s suggested the presence of Quaternary paleo-lake deposits in a number of tributary valleys of the Ohio River. One of the putative paleo-lake deposits was mapped in the Salt River lowlands, located southwest of Louisville (KY); these lake deposits were assigned to the Pleistocene due to stratal relationships. More recent surficial mapping through the STATEMAP program by the Kentucky Geological Survey has begun to shed new light on lacustrine deposits and landforms in this region. This study seeks to clarify the morphology of the Salt River paleo-lake through geomorphic analysis, and to assess its stratigraphy and sedimentology using sediment cores that will be retrieved using a Giddings or Geoprobe device. We present LIDAR data that reveals candidate paleo-shoreline features associated with the Salt River Lake. High resolution digital elevation data are used to inform the core collection strategy. Sediment cores, studied using grain size analysis, magnetic susceptibility, x-ray diffraction, x-ray fluorescence, will be used to validate the existence of the paleo-lake, the distribution of depositional environments, and spatial variability in lithofacies. This presentation will dive into current hypotheses and planned future research on the Salt River paleo-lake.