Stratigraphy and conodont paleontology of the Sexton Creek Limestone and the Salamonie Dolomite (Silurian) in northwestern Indiana (1982)
ABSTRACT: This study of Alexandrian and early Niagaran strata in northwestern Indiana is part of a series of studies of Silurian rocks in the northern part of the state. It is based on geophysical logs, conodonts, and well samples, including cuttings and cores. Alexandrian rocks are represented by the Sexton Creek Limestone, the lower part of which is separated here as the Schweizer Member of the Sexton Creek Limestone. An upper facies of the Sexton Creek is recognized as being equivalent to the Kankakee Formation in Illinois but is not normally named. The main body of the Sexton Creek is cherty impure brown dolomite; the Schweizer lacks chert, is more argillaceous, and includes dolomitic shale. Formation thickness ranges from 1 to 110 feet. The Sexton Creek Limestone is unconformably overlain by the Salamonie Dolomite except that in western Lake County the two may be conformable. The Salamonie Dolomite (Niagaran) is generally light-gray to white granular vuggy dolomite. Chert is irregularly present. The lower part of the formation if finer grained and more argillaceous and is equivalent to the Stroh Member of the Cataract Formation to the east and to part of the Brandon Bridge Member of the Joliet Formation to the west. The known thickness of the Salamonie in the study area ranges from about 50 feet to more than 200 feet.
Rexroad, C. B., Droste, J. B. 1982, Stratigraphy and conodont paleontology of the Sexton Creek Limestone and the Salamonie Dolomite (Silurian) in northwestern Indiana: Indiana Geological Survey Special Report 25, 29 p., 6 fig.
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
611 North Walnut Grove
Bloomington, IN 47405-2208
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.