One dimensional backstripping results from IODP Expedition 318, Site U1356; tectonic implications for the Wilkes Land margin of Antarctica

Author(s): Hayden, Travis G.; Kominz, Michelle A.; Gonzalez, Jhon; Escutia Dotti, Carlota; Brinkhuis, Henk; Klaus, A.; Fehr, A.; Williams, T.; Bendle, J.; Bijl, Peter K.; Bohaty, S.; Carr, S.; Dunbar, R.; Iwai, M.; Jiminez-Espejo, F.; Katsuki, K.; Kong, G.; McKay, R.; Nakai, M.; Olney, M.; Passchier, S.; Pekar, S.; Sugisaki, S.; Tauxe, L.; Tuo, S.; van de Flierdt, C.; Welsh, K.; Yamane, M.; Pross, J.; Riesselman, C.; Röhl, U.; Sakai, T.; Shrivastava, P.; Stickley, C.
Integrated Ocean Drilling Program, Expedition 318 Scientific Party
Author Affiliation(s): Primary:
Western Michigan University, Department of Geosciences, Kalamazoo, MI, United States
CSIC-Universidad de Granada, Spain
Utrecht University, Netherlands
Volume Title: Geological Society of America, 2011 annual meeting
Source: Abstracts with Programs - Geological Society of America, 43(5), p.99-100; Geological Society of America, 2011 annual meeting, Minneapolis, MN, Oct. 9-12, 2011. Publisher: Geological Society of America (GSA), Boulder, CO, United States. ISSN: 0016-7592 CODEN: GAAPBC
Note: In English
Summary: Wilkes Land is the conjugate margin of the Great Australian Bight, which underwent extension, thinning and rifting from ∼160 Ma until breakup at ∼83 Ma. Both Wilkes Land and the Great Australian Bight are considered passive margins, and were thought to be tectonically inactive since breakup at 83 Ma. We have backstripped the U1356 Core recovered from the continental rise off Wilkes Land, Antarctica by IODP Expedition 318. Backstripping input included lithological and sedimentary analysis, paleo-environmental indicators, combined paleomagnetic and biostratigraphic chronologies, and physical properties measurements. Tectonic subsidence shows a major event between 50 and 33.6 Ma, a time represented by a hiatus in the U1356 core. The magnitude of subsidence requires it to be tectonic in origin, and the timing matches with a reorganization of plate motions that represents the transition from slow spreading to fast spreading between Antarctica and Australia, which occurred at approximately 43 Ma. Coupled with a regional seismic framework, and using other Expedition 318 site analyses, the Wilkes Land margin is shown to be far more complex then the simple passive margin currently assumed. We explore several possible causes for the subsidence observed. One clue might be the tertiary episodic volcanism of Southeast Australia, which is suggested to be driven by lithospheric edge effect convection in the asthenosphere. Additional co-authors: A. Klaus, A. Fehr, T. Williams, J. Bendle, P. Bijl, S. Bohaty, S. Carr, R. Dunbar, M. Iwai, F. Jimenez-Espejo, K. Katsuki, G. Kong, R. McKay, M. Nakai, M. Olney, S. Passchier, S. Pekar, S. Sugisaki, L. Tauxe, S. Tuo, C. van de Flierdt, K. Welsh, M. Yamane, J. Pross, C. Riesselman, U. Rohl, T. Sakai, P. Shrivastava, C. Stickley, Expedition 318 Scientific Participants.
Year of Publication: 2011
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 18 Geophysics, Solid-Earth; Antarctica; Asthenosphere; Australasia; Australia; Backstripping; Biostratigraphy; Continental rise; Convection; Cores; Crustal thinning; Expedition 318; Extension tectonics; Geophysical methods; Great Australian Bight; IODP Site U1356; Indian Ocean; Integrated Ocean Drilling Program; Measurement; Ocean floors; One-dimensional models; Passive margins; Physical properties; Plate tectonics; Rifting; Sea-floor spreading; Seismic methods; Southeastern Australia; Southern Ocean; Tectonics; Volcanism; Wilkes Land
Coordinates: S631837 S631837 E1355956 E1355956
Record ID: 2013009998
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States