Granite erratics in Beacon Valley, Antarctica

Details of Research

TitleGranite erratics in Beacon Valley, AntarcticaAbstractWe present the first quantitative attempt at reconciling the source and emplacement of granite erratics in Beacon Valley. The erratics are enigmatic because granite does not crop out in the valley and its nearest subaerial exposure is at least 10 km downstream to the east of the valley. Detailed mapping of the valley shows three types of granite erratics, which are not present in equal amounts and do not show spatial patterns. Pb isotopic and elemental compositions of the erratics eliminate the Metschel Tillite as a source and indicate they derive from the Dry Valley plutons. Our limited study tentatively ties the erratics to suites of plutons, but it does not allow a direct tie of the erratics to specific plutons because of i) the geochemical variability of the plutons and ii) the limited number of erratics that were analysed. Published data suggest the erratics provide evidence of wet-based glaciation, which covered the Dry Valleys and much of Antarctica during the mid-Miocene. Our paper also explains the problems associated with the emplacement of these erratics and the age of the massive ice in Beacon Valley. © 2017 Antarctic Science Ltd.

Details

1st AuthorDickinson, W. AuthorDickinson, W.Williams, G.Hill, M.Cox, S.Baker, J.Year2017JournalAntarctic ScienceVolume29Number4Pages343-355DOI10.1017/S0954102017000013URLhttps://www.scopus.com/inward/recor.....bdd28c926db8d979f3e2880f2PublisherCambridge University PressKeywordsemplacementerraticgeochemical surveygranitegranitoidharborlead isotopemappingplutonquantitative analysissubaerial exposurevalley glacier, AntarcticaBeacon ValleyEast AntarcticaMcMurdo Dry ValleysMcMurdo Dry ValleysTaylor GlacierVictoria LandAuthor KeywordsGeochemical fingerprintGranite Harbour Intrusivesgranitoid plutonslead isotopesMcMurdo Dry Valleyssouthern Victoria LandTaylor Glacier

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CitationDickinson, W., Williams, G., Hill, M., Cox, S. and Baker, J. (2017). Granite erratics in Beacon Valley, Antarctica. Antarctic Science, 29(4): 343-355Antarctica NZ supported?YesNZARI?No