Alum Cave is one of a series of overhanging cliffs along Wolf Creek in section 17, Southern Township. The exposed sandstone has a coating of alum, caused by water trickling down over the face of the cliff from overlying beds of shale containing pyrite or marcasite. Oxidation of these two minerals produce acid solutions that react with the alum contained in shales.
This particular deposit of alum was known to the earliest settlers, and is marked with other mineral resources such as stone coal and saltpeter on the original survey of the county.
Alum was highly valued by pioneers in treatment of several diseases of stock. Unfortunately, no record has been found to indicate how this particular alum deposit was used.
Notes: Stone from this location was used not only in the foundation of the Williamson County court house that used to sit in the center of Marion’s public square but in the foundation of many early Marion businesses like Cox Hardware and the early Goodall Hotel.
(Extracted from Pioneer Folks and Places, Barbara Barr Hubbs, 1939, on sale at the Williamson County Museum)