Correlations and reconstruction models for the 2500-1500 Ma evolution of the Mawson Continent

Abstract

Continental lithosphere formed and reworked during the Palaeoproterozoic era is a major component of pre-1070 Ma Australia and the East Antarctic Shield. Within this lithosphere, the Mawson Continent encompasses the Gawler–Adélie Craton in southern Australia and Antarctica, and crust of the Miller Range, Transantarctic Mountains, which are interpreted to have assembled during c. 1730–1690 Ma tectonism of the Kimban–Nimrod–Strangways orogenies. Recent geochronology has strengthened correlations between the Mawson Continent and Shackleton Range (Antarctica), but the potential for Meso- to Neoproterozoic rifting and/or accretion events prevent any confident extension of the Mawson Continent to include the Shackleton Range. Proposed later addition (c. 1600–1550 Ma) of the Coompana Block and its Antarctic extension provides the final component of the Mawson Continent. A new model proposed for the late Archaean to early Mesoproterozoic evolution of the Mawson Continent highlights important timelines in the tectonic evolution of the Australian lithosphere. The Gawler–Adélie Craton and adjacent Curnamona Province are interpreted to share correlatable timelines with the North Australian Craton at c. 2500–2430 Ma, c. 2000 Ma, 1865–1850 Ma, 1730–1690 Ma and 1600–1550 Ma. These common timelines are used to suggest the Gawler–Adélie Craton and North Australian Craton formed a contiguous continental terrain during the entirety of the Palaeoproterozoic. Revised palaeomagnetic constraints for global correlation of proto-Australia highlight an apparently static relationship with northwestern Laurentia during the c. 1730–1590 Ma time period. These data have important implications for many previously proposed reconstruction models and are used as a primary constraint in the configuration of the reconstruction model proposed herein. This palaeomagnetic link strengthens previous correlations between the Wernecke region of northwestern Laurentia and terrains in the eastern margin of proto-Australia.

Combined U-Pb SHRIMP and Hf isotope study of the Late Paleozoic Yaminué Complex, Rio Negro Province, Argentina: Implications for the origin and evolution of the Patagonia composite terrane

“…10), as indicated by Goodge et al (2004), Hanson et al (2004), Dalziel (2010) and Loewy et al (2011). It would also be consistent with the "proto-SWEAT" connection between Australia and Laurentia proposed by Payne et al (2009), valid between ca. 1740 and 1590 Ma (and likely at immediately earlier and later times).…”

“…1740 and 1590 Ma (and likely at immediately earlier and later times). Payne et al (2009) have emphasized the possible correlation between the >3.1 Ga magmatic lithologies from the Slave craton and the Miller Range, envisaging the latter crustal block, part of the Mawson craton, in East Antarctica, as an orphaned fragment of Laurentia possibly derived from the Slave craton. Precisely, the position we envisage for the Southern Patagonia terrane before its separation from western Laurentia is somewhere in between the Slave Craton and the Miller Range crustal block.…”

“…the El Jagüelito Formation and the Byrd and Beardmore Groups, respectively (González et al, 2011b, and references therein). Particularly convincing has been the identification of Atdabanian-Botomian Archeocyaths with strong affinity with the Antarctica-Australia paleobiogeographic province in limestone Goodge et al, 2004;Hanson et al, 2004;Payne et al, 2009;Dalziel, 2010). (B): Position of Laurentia juxtaposed with the newly assembled Gondwana at ca.…”

Antarctica and supercontinent evolution: historical perspectives, recent advances and unresolved issues

“…Important questions in Antarctica include whether the Mawson Continent extends as far as the Miller and Shackleton ranges, and, if so, whether there is a continuous 1.7 Ga orogen between these outcrops and the Gawler Craton of South Australia (Payne et al 2009). This 1.7 Ga belt passes between the Mawson Continent and Laurentia in most Nuna reconstructions (Zhao et al 2002(Zhao et al , 2004Evans & Mitchell 2011;Zhang et al 2012), challenging arguments that Nuna had already assembled by 1.8 Ga (e.g.…”

“…If this belt does reflect juxtaposition of Laurentia and the Mawson Continent at 1730-1720 Ma (e.g. Betts et al 2008;Payne et al 2009;Boger 2011), then this means a relatively late assembly for this part of Nuna. Another possibility is that c. 1.7 Ga metamorphism in the Miller Range (and, perhaps, the Shackleton Range) is unrelated to Kimban events in South Australia, and is, instead, linked to events at the active margin of Laurentia that should have extended into the Mawson Continent somewhere close to the Miller Range according to the correlations of Goodge et al (2008).…”