Age constraints from the Rocky Cape Group: putting Tasmania on the Mesoproterozoic map

TL;DRAbstract

<p>The oldest known rocks in Tasmania occur in the Proterozoic Rocky Cape Group, a ~10 km thick quartzarenite–siltstone–pelite-dominated succession, which was previously constrained to have been deposited between 1450 Ma and 750 Ma. New detrital zircon and authigenic monazite ages dated <i>via</i> U–Pb Laser Ablation-Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS) sampled from sub-greenschist facies sandstones and siltstones throughout the Rocky Cape Group allow us to: (1) vastly improve on depositional age constraints, including constraining the age of the ‘string of beads’ fossil <i>Horodyskia</i>-bearing strata; (2) make regional basin-scale correlations; and (3) speculate on the tectonic correlations between proto-Australia and Laurentia at <i>ca</i> 1.45 Ga.</p> <p>Detrital zircon and authigenic monazite grains ages analysis yield a deposition window between <i>ca</i> 1450 Ma (youngest zircon populations) an

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