T192 Evolving Perspectives of the Precambrian World: Using Combined Theoretical and Applied Approaches to Tackle Problems at the Intersection of Geology, Geobiology, and Geochemistry (Posters)

Tuesday, 6 November 2018
9:00 AM - 6:30 PM
Halls J-K

A COMPREHENSIVE COMPARISON OF PUBLISHED AGES FOR MAJOR UNITS OF THE SINGHBHUM CRATON INCLUDING NEW DETRITAL ZIRCON AGES

Paper number: T192-9
Program: Technical Sessions
Time: 9:00 AM – 6:30 PM

Authors

Abstract

Since the 1960’s, researchers have used 40K-40Ar, 40Ar-39Ar, 87Rb-86Sr, 147Sm-144Nd whole-rock isochrons, and the U-Pb system (monazite, rutile, and zircon) to chronicle the evolution of Archean cratons. Although at present these systems are not treated with the same authority, past reports may still exact undue influence on the research community’s understanding. In the case of the Singhbhum craton, India, shared lithologies among major units and controversy regarding intrusive relations of units has produced an obtuse Archean history. Recent documentation of Hadean zircons within the craton extend its history to ~4.2 Ga. To demystify Singhbhum craton evolution from Hadean time to presumed stabilization at ~3.1 Ga, we present the most recent comprehensive comparison of reported Singhbhum craton ages and scrutinize intrusive relations that serve to create diverging narratives. We suggest systematic documentation and evaluation of enclaves and intruding units for similar Precambrian assemblages with protracted, but intermittent, histories. Included in the geochronologic dataset are two new 207Pb/206Pb ages for zircons from the Baitarani river sediment near Champua (in search of finding more Hadean signal) and from a quartzite in the western Iron Ore Group. These data will be uploaded to the web-based open source portal geochron.org in hopes of promoting global accessibility for researchers. Prior to this study, there were no zircon data from peninsular India available on geochron.org.

Geological Society of America Abstracts with Programs. Vol. 50, No. 6

doi: 10.1130/abs/2018AM-320193

© Copyright 2018 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.