SEAWATER INTRUSION ON THE GEORGIA COAST The upper Floridan aquifer (UFA) is the principal source of groundwater in coastal Georgia and is also part of the largest aquifer in the southeastern US. In Georgia, the Miocene aquitard ("cap rock") overlying the aquifer helps retain fresh water in the aquifer and also inhibits intrusion of seawater. We recently completed mapping of coastal and inner-shelf areas of Georgia and South Carolina to identify where seawater may be intruding into the UFA. Our study was funded by Georgia DNR's Environmental Protection Division, as part of an interim strategy to acquire the scientific knowledge fundamental to effective future management of groundwater resources in southeastern Georgia. We used state-of-the-art geophysics (seismic-reflection, sidescan, and DGPS systems) in order to accurately locate areas where: (1) the UFA is present at shallow depth and (2) the Miocene aquitard is breached or thinned. We defined Areas of Concern (AOCs) where these two criteria were met in conjunction with (1) an overlying water column that was saline and (2) a potentiometric surface on the aquifer that was near or below mean sea level. At each AOC, either modern tidal channels or infilled Plio-Pleistocene paleochannels cut into or through the aquitard to form potential conduits for seawater to enter the aquifer. Tony Foyle, Clark Alexander and Jim Henry were the Co-PI's on this study.

HIGH-RESOLUTION SEQUENCE STRATIGRAPHY
The southern margin of Lake Erie is an ideal field laboratory within which to study the formation, preservation, and internal geometries of non-tidal beach-ridge plain and associated linear shoreline systems. Lake Erie’s Highstand Systems Tract – Falling Stage Systems Tract deposits (of Pleistocene age) have the potential to reveal process and form details of their ancient marine analogs which are important hydrocarbon reservoirs in passive-margin and foreland basin settings within the rock record. Modern analogs to these systems are currently forming at several locations on the Great Lakes coast today, such as at Presque Isle (PA), Toleston Beach (IN), Zion (IL), and Two Rivers (WI).

GREAT LAKES COASTAL GEOLOGY
The Great Lakes coastline has been described as the United States' fourth coast. Dominated by rocky, bluff, and sandy coasts, the shores of the southern Great Lakes are an excellent location to study the physical processes active upon, and the geomorphic evolution and behavior of, both non-cohesive (sandy) and cohesive (glacial till) sediment-water interfaces.