Determining biostratigraphy and correlation using color alteration index and lithofacies of conodonts in the Edinburg Formation, Central Virginia

Authors

Lauren Showalter, James Madison UniversityFollow

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.

Date of Graduation

5-15-2021

Publish

yes

Degree Name

Bachelor of Science (BS)

Department

Department of Geology and Environmental Science

Second Advisor

Lynn Fichter

Third Advisor

Steven Baedke

Abstract

Conodont species, CAI and lithofacies analysis are used as methods of correlation to determine the relative age, depositional environment, and post depositional burial history of the Edinburg Formation in central Virginia. Samples collected for conodont microfossils yielded faunas of Baltoniodus sp. or Amorphognathus sp., Periodon grandis and Protopanderodus liripipus from a site near Luray and Drepanoistodus suberectus, Plectodina sp., Protopanderodus liripipus, Oistodus sp., Phragmodus undatus, Erismodus radicans and Panderodus gracilis from a site in Harrisonburg. The species supports a Late Ordovician (Late Sandbian age). Conodonts from both sites have a CAI of 4-5, indicating post-depositional heating of over 300 degrees C and suggesting burial depts of over 13-15 km, which is consistent with the ductile folding obvious in the Luray area site. Sample lithologies are consistent with published lithofacies maps, and support deposition in a deep-shelf setting.