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Mesoproterozoic Tasmania: witness to the East Antarctica-Laurentia connection within Nuna
journal contributionposted on 2023-05-22, 00:06 authored by Mulder, JA, Jacqueline HalpinJacqueline Halpin, Daczko, NR
Our detrital zircon U-Pb-Hf isotopic data and paleocurrent indicators from the lower-middle Rocky Cape Group (RCG) of northwest Tasmania, a >10-km-thick package of marine sedimentary rocks, are consistent with a provenance including basement terranes in the southern Mawson continent (East Antarctica) and southwest Laurentia, supporting a SWEAT-like configuration for the supercontinent Nuna between 1.45 and 1.3 Ga (Mulder et al., 2015). Moore and Betts (2016) challenge our proposed paleogeographic position for Tasmania within Nuna. Instead, they champion an alternative position for Proterozoic Tasmania that they claim better fits elements of Tasmanian geology outside of the RCG (Moore et al., 2015). From the outset, we would like to reiterate that the data and paleogeographic reconstruction presented us were discussed in the context of the Nuna supercontinent and based on the most recent reconstruction by Pisarevsky et al. (2014). We specifically addressed the interval 1.45– 1.3 Ga, which encompasses the period in which Nuna started to rift and break apart. Nowhere do we address the reconstructed position of VanDieland—a microcontinent that includes rocks as young as Cambrian, and represents Tasmania (and central Victoria, South Tasman Rise, and East Tasman Plateau) just prior to incorporation into Gondwana (Cayley, 2011). Although most of the points raised by Moore and Betts are not directly relevant to the dataset and reconstruction in our paper, we welcome the opportunity to elaborate on our ongoing research on the Proterozoic tectonics of Tasmania by addressing the issues they have raised.
Department/SchoolSchool of Natural Sciences
PublisherGeological Soc America
Place of publicationInc, Po Box 9140, Boulder, USA, Co, 80301-9140