This site is along a spur railroad cut in the W½NE¼Sec. 28, T.3N., R. 3W., Martin County, Indiana (Fig. 1). It is shown on theHuron 7½-minute Quadrangle and is accessible by foot from acounty road that crosses the railroad just south of the cut. The cutis on the property of the National Gypsum Company, Shoals Plant, and permission to visit should be requested, particularly forgroups.
This is the best and most revealing exposure of the sub-Pennsylvanian disconformity in southern Indiana and is one ofthe best in the entire Illinois Basin. A small pre-Pennsylvanianvalley with about 50 ft (15 m) relief is well shown, and manyfeatures of the rocks above and below the contact are also illustrated. This is an excellent introduction to the stratigraphy ofmuch of southwestern Indiana.