|Lower Potomac Group, Eastern Coastal Plain of Maryland, Delaware, and New Jersey
Trapp and others (1984) and Hansen (1984) provided temperature versus depth information from deep wells in the coastal plain of Maryland. Both studies determine a normal geothermal gradient of about 1.5 °F/100 ft. This compares well with the geothermal gradient data of Kinney (1976) in which a geothermal gradient of about 1.38 °F/100 ft (25.5o C/km) is shown for the eastern New Jersey, Delaware, and Maryland coastal-plain area.
Hansen, H. J., 1984, Hydrogeologic characteristics of the Waste Gate Formation, a new subsurface unit of the Potomac Group underlying the eastern Delmarva Peninsula: Maryland Geological Survey Information Circular 39, 22 p.
Trapp, H., Jr., Knobel, L. L., Meisler, H., and Leahy, P. P., 1984, Test well DO-CE 88 at Cambridge, Dorchester County, Maryland: U.S. Geological Survey, Water-Supply Paper 2229, 48 p.