Controls on localization and densification of a modern décollement: Northern Barbados accretionary prism

Abstract

Research Article| March 01, 2003 Controls on localization and densification of a modern décollement: Northern Barbados accretionary prism G. Wallace; G. Wallace 1Department of Earth Sciences, University of California, Santa Cruz, California 95064, USA Search for other works by this author on: GSW Google Scholar J.C. Moore; J.C. Moore 1Department of Earth Sciences, University of California, Santa Cruz, California 95064, USA Search for other works by this author on: GSW Google Scholar C.G. DiLeonardo C.G. DiLeonardo 1Department of Earth Sciences, University of California, Santa Cruz, California 95064, USA Search for other works by this author on: GSW Google Scholar Author and Article Information G. Wallace 1Department of Earth Sciences, University of California, Santa Cruz, California 95064, USA J.C. Moore 1Department of Earth Sciences, University of California, Santa Cruz, California 95064, USA C.G. DiLeonardo 1Department of Earth Sciences, University of California, Santa Cruz, California 95064, USA Publisher: Geological Society of America Received: 20 Oct 2000 Revision Received: 05 Jun 2002 Accepted: 20 Aug 2002 First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2003) 115 (3): 288–297. https://doi.org/10.1130/0016-7606(2003)115<0288:COLADO>2.0.CO;2 Article history Received: 20 Oct 2000 Revision Received: 05 Jun 2002 Accepted: 20 Aug 2002 First Online: 01 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 G. Wallace, J.C. Moore, C.G. DiLeonardo; Controls on localization and densification of a modern décollement: Northern Barbados accretionary prism. GSA Bulletin 2003;; 115 (3): 288–297. doi: https://doi.org/10.1130/0016-7606(2003)115<0288:COLADO>2.0.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 SocietyGSA Bulletin Search Advanced Search Abstract In the Northern Barbados Ridge area, the décollement zone beneath the accretionary prism lies in a lower Miocene radiolarian claystone. Seismic data allow recognition of this continuous stratigraphic horizon seaward of the accretionary prism. Logging-while-drilling (LWD) data show that the radiolarian claystone is of low density relative to surrounding sediments and indicate that the interval densified heterogeneously with progressive deformation. The low-density interval is relatively weak, and possibly overpressured, which together foster décollement zone propagation. Characterization of densification processes in this interval by image analysis shows that reorientation of clays by shear-enhanced consolidation and tectonic overburden is the dominant densification process. The correlation between densification and clay reorientation suggests that predeformational conditions play a deciding role in décollement propagation.3D seismic reflection data show that the topographic relief of the décollement zone arcward of the deformation front is greater than that in the protodécollement zone and is apparently controlled by basement structure. Thus, it is unlikely that the processes forming the décollement zone are truncating relief in the protodécollement surface, but rather sliding over it along a weak stratigraphic interval. Although localization of the décollement may be originally due to low density and weak sediments, strain softening in a smectite-rich lithology and, perhaps, development of a low permeability cap may contribute to the continued deformation in this stratigraphic interval. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.