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Scratching the surface: a marine sediment provenance record from the continental slope of central Wilkes Land, East Antarctica

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posted on 2023-05-20, 18:39 authored by Tooze, S, Jacqueline HalpinJacqueline Halpin, Taryn NobleTaryn Noble, Zanna ChaseZanna Chase, O'Brien, PE, Armand, L
The geology of Wilkes Land, East Antarctica, is masked by kilometers of ice and remains largely unexplored. Defining the sediment provenance adjacent to this hidden region is important for distinguishing the proximal subglacial basement terranes and refining the dynamic regional glaciological history. This study presents a detrital sediment provenance record spanning c. 23.5 ka from the continental slope of central Wilkes Land. Sediment provenance was characterized using U‐Pb geochronology and trace element geochemistry from detrital zircon, titanite and apatite and Pb‐isotopic signatures from detrital feldspar. These data were compared with new feldspar Pb‐isotopic signatures and existing U‐Pb zircon datasets from rare nearby coastal outcrop. A principally igneous source was revealed with dominant age populations between c. 1360‐1100 Ma and c. 1620‐1490 Ma, characteristic of rocks of the proximal Wilkes and Banzare provinces, respectively. Minor detritus was additionally sourced from the proximal Nuyina Province (c. 1450‐1390 Ma). Temporal variation in the climate and ice sheet configuration are likely responsible for subtle downcore changes observed in detrital sediment provenance. High sedimentation rates during the glacial period suggest reworking of continental shelf sediments and downslope transport in debris flows during ice sheet advance. Glacial meltwater fluxes fed largely by the Totten Glacier were responsible for supplying detritus during deglaciation. During interglacials, detritus was derived from a broad coastal region and delivered to the slope via multiple glacial outlets. These results present the first substantial offshore evidence to support recent interpretations that the subglacial crust of central Wilkes Land has a dominantly Mesoproterozoic history.

History

Publication title

Geochemistry Geophysics Geosystems

Volume

21

Issue

11

Article number

e2020GC009156

Number

e2020GC009156

Pagination

1-23

ISSN

1525-2027

Department/School

Institute for Marine and Antarctic Studies

Publisher

Amer Geophysical Union

Place of publication

2000 Florida Ave Nw, Washington, USA, Dc, 20009

Rights statement

Copyright 2020 the authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/

Repository Status

  • Open

Socio-economic Objectives

Effects of climate change on Antarctic and sub-Antarctic environments (excl. social impacts); Expanding knowledge in the earth sciences

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