Reconstruction of Antarctica and Australia at breakup (95 ± 5 Ma) and before rifting (160 Ma)
Previous reconstructions of Antarctica and Australia were made by fitting the bathymetric outlines of the conjugate margins and aligning pre-existing structures; the precise position of the continent-ocean boundary (COB) and the amount and azimuth of pre-breakup extension were unknown. Seismic and m...
Published in: | Australian Journal of Earth Sciences |
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Main Authors: | , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
1988
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Subjects: | |
Online Access: | https://researchers.mq.edu.au/en/publications/7f497427-403c-4028-9b39-36a1e9904138 https://doi.org/10.1080/08120098808729453 http://www.scopus.com/inward/record.url?scp=0024196527&partnerID=8YFLogxK |
Summary: | Previous reconstructions of Antarctica and Australia were made by fitting the bathymetric outlines of the conjugate margins and aligning pre-existing structures; the precise position of the continent-ocean boundary (COB) and the amount and azimuth of pre-breakup extension were unknown. Seismic and magnetic data collected off Wilkes Land by the S.P. Lee provide: (1) the basis for a unique fit of the COBs by confirming the fit of the oldest magnetic anomalies; and (2) together with information about the deep crustal structure of the Australian margin, an estimate of the azimuth and amount of pre-breakup continental extension. By these means, Antarctica and Australia are reconstructed at the mid-Cretaceous breakup and onset of drift (95 ± 5 Ma) by fitting the conjugate COBs, as determined from seismic and magnetic profiles; and before the mid-Jurassic (160 Ma) onset of rifting by removing the 360 km of continental extension estimated from the crustal structure of the 700 km wide junction zone. |
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