20 Undergraduate and Graduate Geoscience Student Showcase (Posters)

Friday, 17 March 2023
1:30 PM - 5:30 PM
Grand Ballroom A–D

GEOCHEMICAL ANALYSIS OF THE SHALLOW BAY FORMATION AT THE COW HEAD PENINSULA IN NEWFOUNDLAND, CANADA

Paper number: 20-18
Program: Theme Sessions
Time: 1:30 PM – 5:30 PM

Authors

Abstract

This research is part of a larger project to better understand the geologic development of the Appalachian Mountains in the Cow Head region of Western Newfoundland, Canada. Specifically, this particular project focused on analyzing the stratigraphy, geochemistry, and mineralogy of the late Cambrian to early Ordovician age Shallow Bay Formation exposed at Cow Head for mapping purposes. The lithology of the Shallow Bay Formation primarily consists of limestone conglomerates and finely bedded micrite with minor shale. The depositional environment of the sediments is interpreted to represent a base of continental slope to continental rise setting situated between the Laurentian continent and the Iapetus Ocean. Prior research subdivided the Shallow Bay Formation into four distinct members: Downes Point, Tuckers Cove, Stearing Island, and Factory Cove. These members are further subdivided into a total of 14 beds (map units), though many share common lithologies and are therefore difficult to distinguish in the field. Limited microscopy work on a few thin-sections of the limestones and micrites suggested little heterogeneity, regardless of age. Additionally, the thickness of several conglomerate beds and the underlying limestone beds vary greatly, likely due to scouring associated with subaqueous debris flows during the deposition of the conglomerates, making it difficult to produce balanced sections. In an attempt to aid geologic mapping of the Cow Head Peninsula, this research (1) reassesses the subdivisions of map units to limit thickness variability for mapping purposes, and (2) uses geochemical datasets as a tracer to aid in the identification of units for mapping. The latter is done by providing more breadth and depth of compositional analysis to highlight variations across the map units using rock thin-section and powder X-Ray Diffraction (XRD) analysis, and also builds upon previously published carbonate stable isotope data of the map units. Results from this project, using a combination of standard geochemical and petrologic techniques, should provide new insights into compositional variations of the Shallow Bay Formation, which in turn will be used to support geologic mapping of the shoreline and interior of the Cow Head Peninsula.

Geological Society of America Abstracts with Programs. Vol. 55, No. 2

doi: 10.1130/abs/2023SE-386013

© Copyright 2023 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.