Crustal architecture of the oblique-slip conjugate margins of George V Land and southeast Australia.pdf (1.8 MB)
Download fileCrustal architecture of the oblique-slip conjugate margins of George V Land and southeast Australia
conference contribution
posted on 2023-05-23, 06:47 authored by Stagg, HMJ, Anya ReadingAnya ReadingA conceptual, lithospheric-scale cross-section of the conjugate, oblique-slip margins of George V Land, East Antarctica, and southeast Australia (Otway Basin) has been constructed based on the integration of seismic and sample data. This cross-section is characterised by asymmetry in width and thickness, and depth-dependent crustal extension at breakup in the latest Maastrichtian. The broad Antarctic margin (~360 km apparent rift width) developed on thick crust (~42 km) of the Antarctic craton, whereas the narrow Otway margin (~220 km) developed on the thinner crust (~31 km) of the Ross–Delamerian Orogen. The shallow basement (velocities ~5.5 km.s-1) and the deep continental crust (velocities >6.4 km.s-1) appear to be largely absent across the central rift, while the mid-crustal, probably granitic layer (velocities ~6 km.s-1) is preserved. Comparison with published numerical models suggests that the shallow basement and deep crust may have been removed by simple shear, whereas the mid-crust has been ductilely deformed.
History
Publication title
Antarctica: A Keystone in a Changing World - Online Proceedings of the 10th ISAESEditors
AK Cooper and CR Raymond et alPagination
1-6ISSN
0196-1497Department/School
School of Natural SciencesPublisher
US Geological Survey and The National Academies PressPlace of publication
OnlineEvent title
10th International Symposium on Antarctic Earth Sciences (ISAES X - 2007)Event Venue
University of California, Santa Barbara, CA, USADate of Event (Start Date)
2007-08-26Date of Event (End Date)
2007-09-01Rights statement
Copyright 2007 the AuthorsRepository Status
- Open