7 Undergraduate Research I (Posters)

Thursday, 20 March 2025
8:00 AM - 12:00 PM
Shenandoah ABC

ORDOVICIAN CONODONT BIOSTRATIGRAPHY OF THE BETTS QUARRY, HARRISONBURG, VA

Paper number: 7-1
Program: Theme Sessions
Time: 8:00 AM – 12:00 PM

Authors

Abstract

Rocks exposed in the Betts Quarry in Harrisonburg, Virginia have been mapped at different times as either Beekmantown Formation and New Market Limestone or as Beekmantown Formation with a fault bounded block of Edinburg Formation. The unit historically identified as Edinburg was distinguished from the surrounding limestone and dolostone based on its very dark gray to black color and presence of a shale bed at its base. The basal shale bed at Betts Quarry has been interpreted either as fault gouge or as a potential K-bentonite bed. Nine bulk samples were collected for conodont analysis from two sections that span from below the shaley horizon in unequivocal Beekmantown through the black limestone to determine if the dark limestone correlates with the Beekmantown-New Market or the Edinburg. Preliminary conodont data yields a fauna of Curtognathus sp. and Erismodus sp. both above and below the shaley horizon. Below the shale horizon the fauna contains Leptochirognathus cf. quadratus and above the shaley horizon the fauna also contains Plectodina sp., which is consistent with the fauna found in both the Beekmantown and New Market supporting the idea that the black limestone is not the Edinburg Formation.

Geological Society of America Abstracts with Programs. Vol. 57, No. 2

doi: 10.1130/abs/2025SE-407583

© Copyright 2025 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.