71 Undergraduate Research (Posters) III

A PALEONTOLOGICAL ANALYSIS OF THE BRACHIOPODA FROM AN OUTCROP OF LOWER TRENTON LIMESTONE, IN SOUTHERN LEWIS COUNTY, NEW YORK

Paper number: 71-11
Program: THEME SESSIONS
Time: 8:00 AM – 12:00 PM

Authors

Abstract

Broad research such as stratigraphy, stratigraphic correlation and biostratigraphy has been done on the Ordovician Trenton Group. However, with few exceptions, no specific studies have been done on brachiopod identification and simple statistical measures. We were able to determine the general paleoecology for the articulate brachiopods of the Kings Falls Limestone at a single locality in northern New York State.

The articulate brachiopod assemblage is dominated by four genera (in decreasing order): Sowerbyella, Paucicrura, Rafinesquina, and Plectorthis. Equal numbers of brachial and pedicle valves are present, and about 75 percent of all brachiopods are fractured. The fractured brachiopods occur in beds representing normal deposition and storm events. However, most of the broken brachiopods occur on beds representing shell pavements, pararipples, and storm layers that are typical of shallow water environments.

Brachiopods were not the only group that showed fracturing, signifying that a constant process affected all groups equally and possibly at random. Further study may reveal the principle cause of the fracturing from the three likely possiblities: storm events, normal compaction, or overburden pressures.