Multianalytical provenance analysis of Eastern Ross Sea LGM till sediments (Antarctica): Petrography, geochronology, and thermochronology detrital data

In order to reveal provenance of detrital sediments supplied by West Antarctic Ice Sheet (WAIS), 19 glaciomarine cores of Last Glacial Maximum age were analyzed from Eastern Ross Sea and Sulzberger Bay. Analytical techniques included petrographic analysis of gravel-sized clasts, geochronology (zirco...

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Bibliographic Details
Published in:Geochemistry, Geophysics, Geosystems
Main Authors: Perotti, Matteo, Andreucci, Benedetta, Talarico, Franco Maria, Zattin, Massimiliano, Langone, Antonio
Format: Article in Journal/Newspaper
Language:English
Published: 2017
Subjects:
Antarctica
Eastern Ross Sea
Last Glacial Maximum
Marie Byrd Land
sediment provenance
Geophysic
Geochemistry and Petrology
Antarctic
Bindschadler Ice Stream
Byrd
Ross Sea
Sulzberger Bay
Transantarctic Mountains
West Antarctic Ice Sheet
West Antarctica
Antarc*
Ice Sheet
Online Access:http://hdl.handle.net/11365/1033561
https://doi.org/10.1002/2016GC006728
http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1525-2027
Description
Summary:In order to reveal provenance of detrital sediments supplied by West Antarctic Ice Sheet (WAIS), 19 glaciomarine cores of Last Glacial Maximum age were analyzed from Eastern Ross Sea and Sulzberger Bay. Analytical techniques included petrographic analysis of gravel-sized clasts, geochronology (zircon U-Pb: Zrn-UPb) and thermochronology (apatite fission track: AFT) of sand-sized fractions. Petrographic analysis revealed a similarity with the lithologies presently exposed in western Marie Byrd Land (MBL), with major roles played by low-grade metamorphic rocks and granitoids. Furthermore Zrn-UPb and AFT data allowed to identify the ages of formation and cooling of sedimentary source area, consisting of Cambrian-Precambrian basement (i.e., Swanson Formation in western MBL) which underwent at least two episodes of magma intrusion, migmatization and cooling during Devonian-Carboniferous and Cretaceous-Paleocene times. Scarcity of volcanic clasts in the region of Ross Sea along the front of West Antarctica Ice Streams in association with the occurrence of AFT Oligocene-Pliocene dates suggests a localized tectonic exhumation of portions of MBL, as already documented for the opposite side of West Antarctic Rift System in the Transantarctic Mountains. Furthermore, a Zrn-UPb and AFT population of Late Triassic-Jurassic age indicates the presence of unexposed rocks that formed or metamorphosed at that time in the sedimentary source area, which could be identified in McAyeal Ice Stream and Bindschadler Ice Stream catchment areas.

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