Parking: N39° 1.605 W84° 30.576
The Mason Road road-cut is an outstanding and easily accessible exposure of Upper Ordovician strata known as the “Cincinnatian Series.” Four lithographic units are exposed at the site: The Kope Formation, the Fairview Formation, the Bellevue Limestone, and the Miamitown Shale. Only the Kope and Fairview formations are easily accessed; the Bellevue Limestone and Miamitown Shale are near the top of the exposure, and are difficult to reach.
The Kope Formation is over 200 feet thick at the site, although only the upper 28 feet is exposed. The Kope Formation is composed of interbedded limestone, siltstone, and shale, with shale comprising about three-fourths of the total thickness. The most common fossils are small (dime-sized) brachiopods and bryozoans. Crinoid and trilobite fragments, and other trace fossils have also been reported.
Above the Kope Formation is 104 feet of the Fairview Formation. The exact border between these two layers is difficult to identify. Like the Kope Formation, the Fairview Formation is composed of interbedded limestone, siltstone, and shale, but unlike the Kope Formation, the Fairview Formation is about 50% limestone. The most common fossils are brachiopods, bryozoans, and crinoids. The brachiopods tend to be larger than in the Kope Formation (up to 2 inches across), and the crinoids far more abundant. Some small gastropods (under 1 inch) are also found, but not in abundance. Pelecypods, trilobite fragments, cephalopods, and other trace fossils have also been reported.
Above the Fairview formation, but not easily accessible, is a 16-foot thick layer of Belleview Limestone, and a 1.3-foot thick layer of Miamitown Shale.
Text adapted from: Davis, R.A., Cincinnati region: Ordovician statigraphy near the southwest corner of Ohio, Geological Society of America Centennial Field Guide - Southeastern Section, 1986.
In order to log this Earthcache, please do the following:
1. Find at least one fossil at the site.
2. Post in your log the coordinates where your fossil was found. Describe where your fossil was located. Identify the fossil(s) as brachiopod, bryozoan, crinoid or whatever.
3. Using the descriptions of the Kope and Fairview formations on this cache page, explain in your log which formation your fossil(s) most likely came from, and why.
4. OPTIONAL Post photos of yourself at the site and/or photos of your fossil(s) with your log.