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To see, or not to see? Rifted margin extension

2015; Geological Society of America; Volume: 43; Issue: 11 Linguagem: Inglês

10.1130/g36982.1

1943-2682

Ken McDermott, T. J. Reston,

Seismic Waves and Analysis

Research Article| November 01, 2015 To see, or not to see? Rifted margin extension Ken McDermott; Ken McDermott School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK *Current address: ION, 1st Floor, Integra House, Vicarage Road, Egham, Surrey TW20 9JZ, UK. Search for other works by this author on: GSW Google Scholar Tim Reston Tim Reston School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK Search for other works by this author on: GSW Google Scholar Author and Article Information Ken McDermott *Current address: ION, 1st Floor, Integra House, Vicarage Road, Egham, Surrey TW20 9JZ, UK. School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK Tim Reston School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT, UK Publisher: Geological Society of America Received: 18 May 2015 Revision Received: 13 Aug 2015 Accepted: 17 Aug 2015 First Online: 09 Mar 2017 Online Issn: 1943-2682 Print Issn: 0091-7613 © 2015 Geological Society of America Geology (2015) 43 (11): 967–970. https://doi.org/10.1130/G36982.1 Article history Received: 18 May 2015 Revision Received: 13 Aug 2015 Accepted: 17 Aug 2015 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Ken McDermott, Tim Reston; To see, or not to see? Rifted margin extension. Geology 2015;; 43 (11): 967–970. doi: https://doi.org/10.1130/G36982.1 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 A characteristic of rifted margins is the extension discrepancy: i.e., the amount of extension estimated from fault geometries on seismic images is far too little to explain the observed crustal thinning and subsidence. Either the crust has been thinned in some other way or the amount of extension has been severely underestimated. To investigate the latter, we create a model structural section across a rifted margin by focusing extension in the center of a rift, producing successive phases of crosscutting faults. From one side of this section, a synthetic seismic image is generated and interpreted as if it were a real profile. Just as for real margins, apparent listric faults and eroded fault block crests are seen, but these are not present in the model and instead represent intersecting fault surfaces, and are thus diagnostic of polyphase faulting. Just as for real margins, the amount of extension measured from the seismic is only a fraction of the true extension. Just as for real margins, this extension discrepancy increases markedly oceanward. Demonstrably for the synthetic margin, and by implication for real margins, the extension discrepancy is the failure of the seismic method to image unambiguously the polyphase faulting required to accommodate increasing extension, combined with a general lack of awareness of the features, outlined here, diagnostic of such faulting. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.