New constraints from U-Pb, Lu-Hf and Sm-Nd isotopic data on the timing of sedimentation and felsic magmatism in the Larsemann Hills, Prydz Bay, East Antarctica
Edward S Grew, Christopher J Carson, Andrew G Christy, Roland Maas, Greg M Yaxley, Steven D Boger, C Mark Fanning
PRECAMBRIAN RESEARCH | ELSEVIER | Published : 2012
Complexly deformed gneisses in the Larsemann Hills, southern Prydz Bay, are customarily divided into a basement igneous complex (Søstrene Orthogneiss) and overlying metasediments (Brattstrand Paragneiss). New ion microprobe U-Pb zircon ages support this geological model and provide further age constraints for sediment deposition at ca. 1000Ma and high-grade metamorphism at ca. 900Ma. U-Pb zircon data for the Søstrene Orthogneiss, a prominent unit of the basement complex, indicate an igneous protolith age of 1126±11Ma. The igneous protolith of the Blundell Orthogneiss was emplaced at 968±13Ma. The Tassie Tarn Metaquartzite, a unit of the Brattstrand Paragneiss, has an estimated maximum deposi..View full abstract
Awarded by NSF
Awarded by Directorate For Geosciences; Division Of Earth Sciences
Awarded by Division Of Earth Sciences; Directorate For Geosciences
Fieldwork during the 2003/2004 field season and laboratory expenses were supported by NSF grants OPP-0228842 and EAR-0837980 to University of Maine and ASAC 2350 to C.J.C. and E.S.G. C.J.C. conducted ion microprobe (SHRIMP) analysis for this research whilst a holding a honorary position of Visiting Fellow at the Research School of Earth Sciences, Australian National University, Canberra, Australia. Simon Harley is thanked for giving us permission to cite unpublished information on his find of prismatine on Lunar Island. The very detailed, constructive and thoughtful reviews by Ian Fitzsimons and Nigel Kelly are gratefully acknowledged. We thank Davis Station leader Bob Jones and members of the 2003-2004 Australian National Antarctic Research Expedition for logistic support; Professor Eizo Nakamura for facilitating the Li and B analyses at the Okayama University at Misasa, and Chris Gerbi for assistance with preparation of the cathodoluminescence images of zircon on the Tescan SEM in the Department of Earth Sciences, University of Maine. The SEM was funded by NSF MRI 0820946.