Description: Stuctural contours of varying datum digitized from the 1:24,000 Geologic Map Series maps. Structural contours were constructed by geologic map authors when the original geologic maps were published during the Kentucky geologic mapping program (Kentucky Geological Survey - U.S. Geological Survey from 1960 to 1980). Contoured formations were determined by the quadrangle map author, so contour datum may vary across quadrangle boundaries. Therefore contours are not based on the most recent subsurface data and should only be used as a general guideline for the underlying geologic structure.
Contours are in feet above sea level, and may vary in contour interval across quadrangle boundaries. Please note that some contours are projected above the land surface.