Extension of the Exmouth Plateau, offshore northwestern Australia: Deep seismic reflection/refraction evidence for simple and pure shear mechanisms

Research Article| January 01, 1989 Extension of the Exmouth Plateau, offshore northwestern Australia: Deep seismic reflection/refraction evidence for simple and pure shear mechanisms John C. Mutter; John C. Mutter 1Lamont-Doherty Geological Observatory, Palisades, New York 10964-01902Department of Geological Sciences, Columbia University, New York, New York 10027 Search for other works by this author on: GSW Google Scholar Roger L. Larson Roger L. Larson 3Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island 02882-1197 Search for other works by this author on: GSW Google Scholar Author and Article Information John C. Mutter 1Lamont-Doherty Geological Observatory, Palisades, New York 10964-01902Department of Geological Sciences, Columbia University, New York, New York 10027 Roger L. Larson 3Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island 02882-1197 Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1989) 17 (1): 15–18. https://doi.org/10.1130/0091-7613(1989)017<0015:EOTEPO>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation John C. Mutter, Roger L. Larson; Extension of the Exmouth Plateau, offshore northwestern Australia: Deep seismic reflection/refraction evidence for simple and pure shear mechanisms. Geology 1989;; 17 (1): 15–18. doi: https://doi.org/10.1130/0091-7613(1989)017<0015:EOTEPO>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The response to extensional stresses that deformed and finally ruptured the northwest Australian passive margin was achieved by an interplay of simple and pure shear mechanisms. The results of a two-ship seismic reflection and refraction experiment show that the outer Exmouth Plateau is dominated by large rotated blocks bounded by deeply penetrating normal faults, some of which are heavily intruded. Magmatic underplating attended this extension but is absent in the central region where a set of prominent, subhorizontal, mid-crustal arrivals are interpreted to be detachment surfaces. Extensive exploration seismic coverage, drilling, and sampling suggest that deformation on the outer plateau postdates that in the central plateau. We propose that initial deformation of the region was dominated by a simple shear detachment system along low-angle fault planes. This passed laterally and temporally into a region of pure shear deformation characterized by high-angle normal faults and magmatism, and this became the locus of final rupture. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.