This report discusses the production and uses of gypsum and the types of gypsum and anhydrite deposits, their physical and chemical properties, geologic association, and theories of origin. Subsurface studies in southwestern Indiana have revealed rather extensive gypsum deposits in the lower part of the St. Louis limestone. Stratigraphic analysis of this evaporite unit indicates that gypsum (CaSO4. 2H2O) and anhydrite (CaSO4) accumulated in small basins within larger basins (intrasilled basins). The isopach map (pl. 1) suggests that three major intrasilled basins exist in southwestern Indiana and that these basins are aligned in a northwest- southeast direction that corresponds to the trend of the rock formations. The isopleth map (pl. 2) indicates that the maximum accumulation of the evaporites corresponds to the geographic locations of the intrasilled basins. The broad up-and-down movement of the earth's crust (epeirogenic movement) caused the formation of a submarine topography which affects evaporitic environments. Epeirogenic movement, which probably was cyclic, is reflected in a depositional pattern that changes from normal open-sea circulation to a restricted-sea environment and then returns to normal open-sea circulation. The evaporite cycle of marine, 1 penesaline, 2 and marine results from both tectonic and environmental causes.
McGregor, D. J., 1954, Gypsum and anhydrite deposits in southwestern Indiana: Indiana Geological Survey Report of Progress 8, 24 p., 2 figs., 2 pl.
You may also like:
Can't find what you're looking for? Feel free to contact us directly:
Publication Sales Office
Indiana Geological and Water Survey
420 N. Walnut St.
Bloomington, IN 47404
IGS Return Policy
All sales are final. Materials may not be returned after they have been accepted by the customer. Any discrepencies in mail orders must be reported to IGWS within 10 days of receipt of order.
The Indiana Geological and Water Survey will refund the purchase price and sales tax of products if returned with the original sales receipt within 10 days of receipt of order. Refunds will be issued with the same method of payment as indicated on the original receipt except for cash purchases, which will be refunded by check. Items must be returned in the same condition as purchased. Refunds on digital products and services are not allowed, except for defective media such as CD-ROMs, flash drives, and so on. The customer is responsible for paying shipping costs to return items.