eCite Digital Repository

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


Mulder, JA and Halpin, JA and Daczko, NR, Mesoproterozoic Tasmania: witness to the East Antarctica-Laurentia connection within Nuna, Geology, 43, (9) pp. 759-762. ISSN 0091-7613 (2015) [Refereed Article]

Copyright Statement

Copyright 2015 Geological Society of America

DOI: doi:10.1130/G36850.1


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 presentday 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:Refereed Article
Keywords:detrital zircon, Hf-isotopes, Nuna, Rocky Cape Group, Tasmania
Research Division:Earth Sciences
Research Group:Geology
Research Field:Structural geology and tectonics
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the earth sciences
UTAS Author:Mulder, JA (Mr Jacob Mulder)
UTAS Author:Halpin, JA (Dr Jacqueline Halpin)
ID Code:102216
Year Published:2015
Web of Science® Times Cited:40
Deposited By:Centre for Ore Deposit Research - CODES CoE
Deposited On:2015-08-04
Last Modified:2017-11-02

Repository Staff Only: item control page