eCite Digital Repository

Mesoproterozoic Tasmania: witness to the East Antarctica-Laurentia connection within Nuna

Citation

Mulder, JA and Halpin, JA and Dazcko, NR, Mesoproterozoic Tasmania: witness to the East Antarctica-Laurentia connection within Nuna, Geological Society of Australia Abstracts, November 2015, Caloundra, Queensland, pp. abstract 106. ISSN 0729-011X (2015) [Conference Extract]


Preview
PDF
Pending copyright assessment - Request a copy
490Kb
  

Abstract

Most recent paleogeographic reconstructions of the supercontinent Nuna juxtapose the North Australian craton, Mawson continent (South Australia–East Antarctica), and Laurentia between 1.6 Ga and 1.3 Ga but differ in their relative positioning. The >10-km-thick siliciclastic Rocky Cape Group of Tasmania was deposited in an opening marine basin on the margin of East Antarctica during Nuna breakup. Based on a similar detrital zircon signature and depositional age, the Rocky Cape Group has been correlated with the upper Belt-Purcell Supergroup in Laurentia, thus representing a key tie point within Nuna. Here the detrital zircon age signature of Mesoproterozoic Rocky Cape Group quartzites is investigated by comparing new detrital zircon U-Pb-Hf isotopic data to an extensive compilation of zircon isotopic data from Australia, East Antarctica, and Laurentia. Our analysis demonstrates that the Rocky Cape Group is unlikely to have been sourced from any geological terrane exposed in present- day Australia. Instead, zircon U-Pb-Hf isotopic data from basement terranes in Laurentia and East Antarctica show striking similarities to the Rocky Cape Group detrital signature. Paleocurrent data indicate that the majority of sediment in the Rocky Cape Group was sourced from Laurentia, which was to the southeast (present-day coordinates) of Tasmania, supporting a SWEAT-like (southwest United States–East Antarctica) configuration for Nuna. We suggest that rifting left a thinned continental connection between East Antarctica and Laurentia onto which the lower-middle Rocky Cape Group was deposited between 1.45 and 1.30 Ga.

Item Details

Item Type:Conference Extract
Keywords:Nuna, Rodina, Rocky Cape Group, zircon, Laurentia
Research Division:Earth Sciences
Research Group:Geology
Research Field:Tectonics
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Earth Sciences
Author:Mulder, JA (Mr Jacob Mulder)
Author:Halpin, JA (Dr Jacqueline Halpin)
ID Code:110591
Year Published:2015
Deposited By:Centre for Ecology and Biodiversity
Deposited On:2016-08-03
Last Modified:2016-08-04
Downloads:0

Repository Staff Only: item control page