|Cape Fear Formation, South Carolina Coastal Plain
Several studies characterize the confining unit above the Cape Fear Formation as a tight marine shale (Aucott and others, 1987; Aucott, 1988; Miller, 1990), and the shale interval is easy to recognize in published cross sections (Colquhoun and others, 1983; Aucott and others, 1987). Aucott (1988) provided a map showing the distribution leakage coefficient of the Cape Fear confining unit. He defined the leakage coefficient as the vertical hydraulic conductivity (~2 ' 10 -7 ft/day) divided by the confining unit thickness (~50 ft). The map in the GIS is from Aucott (1988; his fig. 31).
Aucott, W. R., 1988, The predevelopment ground-water flow system and hydrologic characteristics of the Coastal Plain aquifers of south Carolina: U.S. Geological Survey, Water-Resources Investigations Report 86-4347, 66 p.
Aucott, W. R., Davis, M. E., and Speiran, G. K., 1987, Geohydrologic framework of the Coastal Plain aquifers of South Carolina: U.S. Geological Survey, Water-Resources Investigations Report 85-4271, 7 sheets.
Colquhoun, D. J., Woollen, L. D., Van Nienwenhuise, D. S., Padgett, G. G., Oldham, R. W., Boylan, D. C., Bishop, J. W., and Howell, P. D., 1983, Surface and subsurface stratigraphy, structure and aquifers of the South Carolina Coastal Plain: Columbia, SC, State of South Carolina, Office of the Governor, 78 p.
Miller, J. A., 1990, Ground water atlas of the United States-segment 6, Alabama, Florida, Georgia, and South Carolina: U.S. Geological Survey Hydrologic Investigations Atlas No. HA-730-G, 28 p.