Bracciated Greenfield Dolomite containing porphyroclasts of dolomite and sphalerite. The sample comes from a graben in the central uplift (from page 396 of The Serpent Mound Cryptoexplosion Structure, Southwestern, Ohio by Stephen P. Reidel and Frank L. Koucky part of the Geological Society of America's GSA Cincinnati '81 Field Trip Guidebooks, v. 2. Economic Geology, Structure). The Serpent Mound Impact Structure is an approximately 9-mile-diameter area of highly disturbed and structurally deformed bedrock at the intersection of Adams, Highland and Pike counties. The area of the impact structure has dolomite, shale, limestone, sandstone, and siltstone lithologies. Because of the geologic forces that have acted on the site of the impact [...]
