T114 The Neoproterozoic to Paleozoic Evolution of the Eastern Laurentian Margin—Tectonic, Stratigraphic, Sedimentologic, and Geochronologic Evidence: In Honor of William A. “Bill” Thomas (Posters)

Monday, 16 October 2023
8:00 AM - 5:30 PM
Hall B

INVESTIGATING ‘TOO YOUNG’ DETRITAL ZIRCON AGE POPULATIONS FROM METASEDIMENTARY ROCKS OF THE BLUE RIDGE AND INNER PIEDMONT IN THE SOUTHERN APPALACHIAN MOUNTAIN BELT

Paper number: T114-2
Program: Technical Sessions
Time: 8:00 AM – 5:30 PM

Authors

Abstract

The southern Appalachian mountain belt is an accretionary orogen that formed in the southeastern United States through several phases of oceanic subduction and continental collision during the Paleozoic Era and culminated in the formation of the supercontinent Pangaea. Despite the importance of terrane accretion in the formation of Pangaea and the southern Appalachians, there remains great uncertainty regarding the nature and location of terrane boundaries in the southern Appalachians. Herein, I present preliminary U-Pb zircon data from metasedimentary rocks of the Blue Ridge and Inner Piedmont which contain age populations younger than the conventional interpretations of the rocks’ depositional ages. If these ages are truly reflective of the crystallization ages of their magmatic sources, the understanding of Appalachian tectonics could shift substantially. The apparent ‘too-young’ ages could also result from disruption by lead-loss, be metamorphic ages, or natural magmatic contaminants intruded into the sedimentary protolith and subsequently obscured by metamorphism. A combination of crystal imaging, elemental ratios and crystal age-depth relationships may be able to differentiate between magmatic (detrital), disrupted, metamorphic, and neo-magmatic origins for the youngest zircons in the samples from the Eastern Blue Ridge and Inner Piedmont of northwestern South Carolina, and parts of adjacent North Carolina.

Geological Society of America Abstracts with Programs. Vol. 55, No. 6

doi: 10.1130/abs/2023AM-392747

© 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.