52 Reconstructing Past Climate from the Geologic Record of Ice Sheets and Mountain Glaciers (Posters)

Tuesday, 19 March 2019
8:00 AM - 12:00 PM
Casco Bay Hall

LINKING SEDIMENTARY TEXTURES TO NEOPROTEROZOIC CLIMATE DYNAMICS

Paper number: 52-4
Program: Theme Sessions
Time: 8:00 AM – 12:00 PM

Authors

Abstract

The surface textures of siliciclastic grains, or “microtextures”, reflect the transport history and depositional environment of sedimentary grains, which in turn reflects the climate history during active sediment transport. Recently, Smith (2016) demonstrated that the physical and chemical quartz microtextures found in modern humid, arid, and glacial fluvial systems can serve as paleoclimate indicators. This result, when invoked alongside Walker et al.’s (1981) model of silicate weathering as a long-term control for Earth’s global climate, suggests that global climatic events like the Cryogenian “Snowball Earth” events may leave microtextural signatures in preserved sediments. This study examined the surface microtextures and elemental compositions of lithified Cryogenian and Ediacaran sediments using a combination of petrography, semi-quantitative energy dispersive spectrometry (EDS), and scanning electron microscopy (SEM), in order to explore potential relationships between siliciclastic microtextures and global climate states. During this process, we also tested existing sample preparation methods (acidification, SelFrag, mechanical disaggregation, citrate-bicarbonate-dithionite (CBD)) to assess the types of lithified samples that are amenable to microtextural analysis.

Geological Society of America Abstracts with Programs. Vol. 51, No. 1

doi: 10.1130/abs/2019NE-328651

© Copyright 2019 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.