Gamburtsev Subglacial Mountains provenance of Permian-Triassic sandstones in the Prince Charles Mountains and offshore Prydz Bay: Integrated U-Pb and T(DM) ages and host-rock affinity from detrital zircons

Permian-Triassic drainage radiates from the Gamburtsev Subglacial Mountains (GSM) in central Antarctica. Proximal to the GSM are Permian-Triassic fluvial sandstones in the Prince Charles Mountains (PCM), and neighbouring ?Triassic red beds in Prydz Bay (PB) ODP740A. We analysed detrital zircons for U-Pb ages, Hf-isotope compositions, and trace elements to determine the age, rock-type and source of the host magma, and "crustal" model age (TDM C). Populations of detrital zircons are (1) 700 to 500 Ma, host magmas granitoid and alkaline rock, TDM C ranges from 2.5 to 1.1 Ga, and (2) 1200-800 Ma, host magmas mafic granitoid and alkaline rock, TDM C 2.1 to 1.5 Ga. The bedrock of the PCM-PB region is a potential provenance of the detrital zircons, but the same populations in Permian siltstone south of the PCM and in sediment inclusions in ice at Lake Vostok indicate that the GSM-Vostok Subglacial Highlands (VSH) are the main provenance. Similar detrital zircons in other sandstones in Gondwanaland downslope from a wider central Antarctic reflect an upslope provenance including the GSM-VSH as a complex of 1200-800 Ma (Grenville) and older cratons with mafic granitoids embedded in 700-500 Ma fold belts with granitoids and alkaline rocks. During the past 1000 Ma, the GSM has undergone intermittent uplift on a scale resembling that of the present uplands of Central Asia.27 page(s