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Mesoproterozoic Tasmania: witness to the East Antarctica-Laurentia connection within Nuna
Citation
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
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 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 |
| Downloads: | 0 |
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