A FOSSIL GUIDE FOR THE COMMUNITY: THE SHALE PIT AT BEAVER SPRINGS

This study will produce a fossil guide for the public from a shale pit owned by Spring Township located at Beaver Springs, PA. This shale exposure, located along Shale Pit Road, represents the Sherman Ridge Member of the Mahantango Formation (Middle Devonian- Givetian). At this location, the exposure is composed of 9-10 m of dark, iron-stained greenish-gray shale, however there is a thin, light bluish-gray, iron-stained shaley-sandstone ledge, ~1 m thick, that occurs within the succession.

The shale contains rare to sparse bivalves (Nuculoidea), straight cephalopods, trilobites (Phacops?), several types of gastropods (Platycera, Bembexia, and Phragmosphaera), crinoid stems and a partial calyx, and carbonized wood. The sandstone contains common to abundant brachiopods (Strophomenids, Microspirifera, Mediospirifera), bivalves (Modiomorpha, Pholadella, Glossites, Pseudoavilculapecten, Pteriacae, Paleoneilo), trilobites (Phacops), crinoid columnals, and encrusting bryozoans. Additionally, a Skolithos ichnofacies was identified in the shaley sandstone.

Preliminary findings indicate that the shale and sandstone represent different depositional environments. The shale environment is interpreted to represent a subtidal, low energy/oxygen, sediment starved environment in the photic zone where algae was able to grow; it is representative of a offshore environment. The sandstone environment represents a high energy/oxygen-rich environment, also in the photic zone; it is possibly a shoreface environment. This work provides a picture guide to help identify fossils, useful information about fossil preservation and environmental interpretations, and it provides practical information about the site. It is hoped that the public can use this guide to also identify the fossils in other, nearby locations.