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Early India-Australia spreading history revealed by newly detected Mesozoic magnetic anomalies in the Perth Abyssal Plain
Citation
Williams, SE and Whittaker, J and Granot, R and Muller, DR, Early India-Australia spreading history revealed by newly detected Mesozoic magnetic anomalies in the Perth Abyssal Plain, Journal of Geophysical Research - Solid Earth, 118, (7) pp. 3275-3284. ISSN 2169-9313 (2013) [Refereed Article]
Copyright Statement
Copyright 2013 American Geophysical Union
Abstract
The seafloor within the Perth Abyssal Plain (PAP), offshoreWestern Australia, is the only
section of crust that directly records the early spreading history between India and Australia
during the Mesozoic breakup of Gondwana. However, this early spreading has been poorly
constrained due to an absence of data, including marine magnetic anomalies and data
constraining the crustal nature of key tectonic features. Here, we present new magnetic
anomaly data from the PAP that shows that the crust in the western part of the basin was part of
the Indian Plate—the conjugate flank to the oceanic crust immediately offshore the Perth
margin, Australia. We identify a sequence of M2 and older anomalies in the west PAP within
crust that initially moved with the Indian Plate, formed at intermediate half-spreading rates
(35 mm/yr) consistent with the conjugate sequence on the Australian Plate. More
speculatively, we reinterpret the youngest anomalies in the east PAP, finding that the M0-age
crust initially formed on the Indian Plate was transferred to the Australian Plate by a westward
jump or propagation of the spreading ridge shortly afterM0 time. Samples dredged from the
Gulden Draak and Batavia Knolls (at the western edge of the PAP) reveal that these
bathymetric features are continental fragments rather than igneous plateaus related to
Broken Ridge. These microcontinents rifted away from Australia with Greater India
during initial breakup at ~130Ma, then rifted from India following the cessation of
spreading in the PAP (~101–103Ma).
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | marine magnetics, tectonics, reconstruction |
| 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: | Whittaker, J (Associate Professor Jo Whittaker) |
| ID Code: | 88443 |
| Year Published: | 2013 |
| Web of Science® Times Cited: | 40 |
| Deposited By: | IMAS Research and Education Centre |
| Deposited On: | 2014-02-03 |
| Last Modified: | 2017-10-30 |
| Downloads: | 0 |
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