Age and composition of Antarctic bedrock reflected by detrital zircons, erratics, and recycled microfossils in the Prydz Bay–Wilkes Land–Ross Sea–Marie Byrd Land sector (70°–240°E) J.J. Veevers ⁎, A. Saeed GEMOC ARC National Key Centre, Department of Earth and Planetary Sciences, Macquarie University, Sydney NSW 2109, Australia abstract article info Article history: Received 23 July 2010 Received in revised form 25 February 2011 Accepted 10 March 2011 Available online 1 April 2011 Handling Editor: J.G. Meert Keywords: Detrital zircons U–Pb ages Hf-isotopes Erratics Recycled microfossils Ice-covered Antarctica The age and composition of the 14 × 10 6 km 2 of Antarctica's surface obscured by ice is unknown except for some dates on detrital minerals. In remedy, we bring together proxies of Antarctic bedrock in the form of (1) detrital zircons analysed for U–Pb age, T DM C , εHf, and rock type, including five new analyses of Neogene turbidites, (2) erratics that reflect age, composition, and metamorphism, and (3) recycled microfossils that reflect age, facies, and metamorphism. Each sample is located in its ice-drainage basin for backtracking to the potential provenance. Gaps in age between sample and upslope exposure are specifically attributable to the provenance. This work indicates that the central Antarctic provenance about a core of the Gamburtsev Subglacial Mountains (GSM) and Vostok Subglacial Highlands (VSH) contains a basement that includes igneous (mafic granitoids) and metamorphic rocks with peak U–Pb ages of 0.5–0.7, 0.9–1.3, 1.4–1.7, 1.9–2.1, 2.2–2.3, 2.6–2.8, and 3.15–3.35 Ga, T DM C 1.3–3.6 Ga, and εHf + 12 to -40. Other modelled cratons with similar ages are set in a matrix of foldbelts of 0.5–0.7 Ga age. The basement in the core is surmounted by Permian red beds, at the periphery by Permian and Triassic sedimentary rocks unaffected by igneous heating or load metamorphism, and west of the Transantarctic Mountains (TAM) in the Wilkes Basin arguably by Late Cretaceous through Pliocene marine sediments. Erratics of undated red sandstone along the coast of Wilkes Land and George V Land indicate a red-bed provenance in the interior. The Prince Charles Mountains (PCM) provide an exposed example of a crust of Precambrian igneous and metamorphic rocks and Permian and Triassic sedimentary rocks. © 2011 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved. 1. Introduction We examine three kinds of evidence for the age and composition of the ~ 98% of Antarctic bedrock (14 × 10 6 km 2 or 9% of the Earth's land area) covered by ice: (1) detrital zircons in sediment shed from Antarctica (e.g., Belyatsky et al., 2010), including new analyses of detrital zircons from strategically located deep-sea (turbiditic) sand; (2) erratics on land and offshore; and (3) recycled microfossils. Ice carries material plucked from bedrock in the Antarctic interior to the coast and offshore where it is deposited as till, and funnelled through canyons in the slope to turbidite fans on the continental rise (O'Brien et al., 2005). Two ice drainages were examined. (1) The coastal sector 70° to 155°E (BD’, Prydz Bay–Wilkes–Terre Adélie– George V Land), with the second largest outflow of ice (Fig. 1), receives material from the ice divide through domes A–B and the spur at ~95° E. During times of ice retreat, the TAM acts as a dam to divert flow into the Wilkes Basin (Hambrey and Barrett, 1993, fig. 14). (2) The drainage exiting in the 155° to 240° (D′G) sector in the Ross Sea receives material from West Antarctica on one side and from the ice divide H–A–B–C on the other. During times of ice growth, material is carried from the interior, including the Wilkes Basin, through valleys in the TAM, in particular the Byrd Glacier (BG), to mingle with material from West Antarctica. In both regions (Fig. 1), recycled microfossils (e.g., Truswell, 1982, 1987; Truswell and Drewry, 1984) reflect provenances younger than the youngest rocks dated by U–Pb zircon (~ 500 Ma). Detrital zircons in marine turbidites (DSDP 268, 269, 273, 274) reflect the age, rock type, εHf, and T DM c of bedrock in the adjacent drainage basin. The jointly analysed detrital zircons provide a more distinctive picture of the provenance than U–Pb age data alone. Dated (U–Pb) detrital zircons from the Shackleton Glacier (Elliot and Fanning, 2008) and the Byrd Glacier (Licht and Palmer, 2007; Palmer, 2008; Palmer and Licht, 2007) come from interior East Antarctica, and those from localities in the Ross Sea (Palmer, 2008; Palmer and Licht, 2007) from East and West Antarctica. Gondwana Research 20 (2011) 710–738 ⁎ Corresponding author. Tel.: + 61 2 9858 1034; fax: +61 2 9850 8943. E-mail address: john.veevers@mq.edu.au (J.J. Veevers). 1342-937X/$ – see front matter © 2011 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved. doi:10.1016/j.gr.2011.03.007 Contents lists available at ScienceDirect Gondwana Research journal homepage: www.elsevier.com/locate/gr