A Proterozoic Wilson cycle identified by Hf isotopes in central Australia: Implications for the assembly of Proterozoic Australia and Rodinia R.G. Smits et al., New South Wales Institute of Frontiers Geoscience, University of Newcastle, Newcastle, New South Wales 2308, Australia; and Centre for Tectonics, Resources and Exploration (TRaX), School of Earth and Environmental Sciences, University of Adelaide, Adelaide, South Australia 5005, Australia; email@example.com. Posted online 10 January 2014, http://dx.doi.org/10.1130/G35112.1.
From the abstract: Current models for the assembly of Proterozoic Australia suggest that the North Australian craton West Australian craton, and South Australian craton had amalgamated by at least 1.6 billion years ago, with possible rafting and reattachment of the South Australian craton by about 1.3 billion years ago. In this scenario, the younger Grenvillian-aged Musgrave Province of central Australia, which separates all three cratons, has been considered postcollisional to intracratonic. However, new and recent U-Pb and Lu-Hf isotopic analyses of zircons from the Musgrave Province indicate continuous active-margin magmatic activity between 1.7 and 1.2 billion years ago. This favors an Australia-Mexico configuration at 1.2 Ga, rather than the southwestern United States and East Antarctica or Proterozoic Australia-western United States (AUSWUS) models. The Musgrave-AFO marks a major, underestimated phase of Rodinian assembly.
Increased channelization of subglacial drainage during deglaciation of the Laurentide Ice Sheet
Robert D. Storrar et al., Department of Geography, Durham University, South Road, Durham DH1 3LE, UK; firstname.lastname@example.org<
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Geological Society of America