A FACIES ANALYSIS OF A CARBONATE DEPOSIT IN THE BRASSFIELD FORMATION NEAR FAIRBORN, OHIO

The Reed North Quarry, located near Fairborn, Ohio, is the future site of a park being developed for science education and research. The quarry exposes the Silurian Brassfield Formation, which is also present in many areas of the Midwest including Kentucky, Indiana, Illinois, Tennessee, and Arkansas. Plans for the quarry include a geology walk where the fossiliferous Brassfield limestone and other features of geological interest including glacial striations can be viewed and preservation of spoil piles where fossils can be collected. Educational materials for use at a variety of levels are in the process of being developed.

The Brassfield at the quarry site is extremely fossiliferous and considerable research has been performed in the quarry including work on echinoderms, corals, and stromatoporoids. Previous researchers have described two coral reefs in this quarry as well as the depositional environments of reef-associated facies. The purpose of this study is to determine the depositional environment and diagenetic history of each of the facies exposed in the quarry. Five localities along the quarry high wall were chosen where the thickest section of Brassfield limestone was exposed. A surprising variation of color and composition of limestone and dolostone is preserved in the 8.0+ meter-thick Brassfield limestone at the quarry. Macroscopic and microscopic evaluation of hand samples taken at 0.5 meter intervals will allow determination of composition and extent of cementation and dolomitization. Facies at the five localities will be tied to each other and a map of the distribution of facies in the quarry produced. This information will be used in the development of educational resources for the quarry park.