Byrd Ice Core Debris Constrains the Sediment Provenance Signature of Central West Antarctica

Abstract Provenance records from sediments deposited offshore of the West Antarctic Ice Sheet (WAIS) can help identify past major ice retreat, thus constraining ice‐sheet models projecting future sea‐level rise. Interpretations from such records are, however, hampered by the ice obscuring Antarctica...

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Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: J. W. Marschalek, P.‐H. Blard, E. Sarigulyan, W. Ehrmann, S. R. Hemming, S. N. Thomson, C.‐D. Hillenbrand, K. Licht, J.‐L. Tison, L. Ardoin, F. Fripiat, C. S. Allen, Y. Marrocchi, M. J. Siegert, T. van deFlierdt
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2024
Subjects:
West Antarctic Ice Sheet
clay mineralogy
sediment provenance
geochemistry
geochronology
Geophysics. Cosmic physics
QC801-809
Antarc*
Antarctic
Antarctica
ice core
Ice Sheet
West Antarctica
Online Access:https://doi.org/10.1029/2023GL106958
https://doaj.org/article/4338bfdfd9d54bd3a524e0528fddaf44
Description
Summary:Abstract Provenance records from sediments deposited offshore of the West Antarctic Ice Sheet (WAIS) can help identify past major ice retreat, thus constraining ice‐sheet models projecting future sea‐level rise. Interpretations from such records are, however, hampered by the ice obscuring Antarctica's geology. Here, we explore central West Antarctica's subglacial geology using basal debris from within the Byrd ice core, drilled to the bed in 1968. Sand grain microtextures and a high kaolinite content (∼38–42%) reveal the debris consists predominantly of eroded sedimentary detritus, likely deposited initially in a warm, pre‐Oligocene, subaerial environment. Detrital hornblende 40Ar/39Ar ages suggest proximal late Cenozoic subglacial volcanism. The debris has a distinct provenance signature, with: common Permian‐Early Jurassic mineral grains; absent early Ross Orogeny grains; a high kaolinite content; and high 143Nd/144Nd and low 87Sr/86Sr ratios. Detecting this “fingerprint” in Antarctic sedimentary records could imply major WAIS retreat, revealing the WAIS's sensitivity to future warming.

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