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Offscraping and underthrusting of sediment at the deformation front of the Barbados Ridge: Deep Sea Drilling Project Leg 78A

1982; Geological Society of America; Volume: 93; Issue: 11 Linguagem: Inglês

10.1130/0016-7606(1982)93 2.0.co;2

1943-2674

J. Casey Moore, B. Biju‐Duval, James A. Bergen, GRANT BLACKINGTON, George E. Claypool, Darrel S. Cowan, Fred K. Duennebier, Rodolfo T. Guerra, Christoph Hemleben, Donald M. Hussong, Michael S. Marlow, James H. Natland, Carol J. Pudsey, G. W. Renz, Marc Tardy, Mark E. Willis, Douglas S. Wilson, AUDREY A. WRIGHT,

Geological and Geophysical Studies

Research Article| November 01, 1982 Offscraping and underthrusting of sediment at the deformation front of the Barbados Ridge: Deep Sea Drilling Project Leg 78A J. CASEY MOORE; J. CASEY MOORE (Co-Chief Scientist) 1Earth Sciences and Center for Coastal Marine Studies, University of California, Santa Cruz, Santa Cruz, California 95064 Search for other works by this author on: GSW Google Scholar BERNARD BIJU-DUVAL; BERNARD BIJU-DUVAL (Co-Chief Scientist) 2Institut Francais du Petrole, Rueil Malmaison, France Search for other works by this author on: GSW Google Scholar JAMES A. BERGEN; JAMES A. BERGEN 3Department of Geology, Florida State University, Tallahassee, Florida 32306 Search for other works by this author on: GSW Google Scholar GRANT BLACKINGTON; GRANT BLACKINGTON 4Hawaii Institute of Geophysics, University of Hawaii, Honolulu, Hawaii 96822 Search for other works by this author on: GSW Google Scholar GEORGE E. CLAYPOOL; GEORGE E. CLAYPOOL 5Oil and Gas Branch, U.S. Geological Survey, Denver, Colorado 80225 Search for other works by this author on: GSW Google Scholar DARREL S. COWAN; DARREL S. COWAN 6Department of Geological Sciences, University of Washington, Seattle, Washington 98195 Search for other works by this author on: GSW Google Scholar FRED DUENNEBIER; FRED DUENNEBIER 4Hawaii Institute of Geophysics, University of Hawaii, Honolulu, Hawaii 96822 Search for other works by this author on: GSW Google Scholar RODOLFO T. GUERRA; RODOLFO T. GUERRA 7Mobil Corporation, Box 900, Dallas, Texas 75221 Search for other works by this author on: GSW Google Scholar CHRISTOPH H. J. HEMLEBEN; CHRISTOPH H. J. HEMLEBEN 8Institut und Museum für Geologie und Paleontologie, Universitat Tubingen, Tubingen, Federal Republic of Germany Search for other works by this author on: GSW Google Scholar DONALD HUSSONG; DONALD HUSSONG 9Hawaii Institute of Geophysics, University of Hawaii, Honolulu, Hawaii 98195 Search for other works by this author on: GSW Google Scholar MICHAEL S. MARLOW; MICHAEL S. MARLOW 10Marine Geology, U.S. Geological Survey, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar JAMES H. NATLAND; JAMES H. NATLAND 11Deep Sea Drilling Project, Scripps Institution of Oceanography, La Jolla, California 92093 Search for other works by this author on: GSW Google Scholar CAROL J. PUDSEY; CAROL J. PUDSEY 12Department of Geology and Mineralogy, University of Oxford, Oxford, United Kingdom Search for other works by this author on: GSW Google Scholar G. W. RENZ; G. W. RENZ 11Deep Sea Drilling Project, Scripps Institution of Oceanography, La Jolla, California 92093 Search for other works by this author on: GSW Google Scholar MARC TARDY; MARC TARDY 13Laboratoire des Sciences de la Terre, Universite de Savoie, Chambery, France Search for other works by this author on: GSW Google Scholar MARK E. WILLIS; MARK E. WILLIS 14Department of Earth & Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 Search for other works by this author on: GSW Google Scholar DOUGLAS WILSON; DOUGLAS WILSON 9Hawaii Institute of Geophysics, University of Hawaii, Honolulu, Hawaii 98195 Search for other works by this author on: GSW Google Scholar AUDREY A. WRIGHT AUDREY A. WRIGHT 1Earth Sciences and Center for Coastal Marine Studies, University of California, Santa Cruz, Santa Cruz, California 95064 Search for other works by this author on: GSW Google Scholar Author and Article Information J. CASEY MOORE (Co-Chief Scientist) 1Earth Sciences and Center for Coastal Marine Studies, University of California, Santa Cruz, Santa Cruz, California 95064 BERNARD BIJU-DUVAL (Co-Chief Scientist) 2Institut Francais du Petrole, Rueil Malmaison, France JAMES A. BERGEN 3Department of Geology, Florida State University, Tallahassee, Florida 32306 GRANT BLACKINGTON 4Hawaii Institute of Geophysics, University of Hawaii, Honolulu, Hawaii 96822 GEORGE E. CLAYPOOL 5Oil and Gas Branch, U.S. Geological Survey, Denver, Colorado 80225 DARREL S. COWAN 6Department of Geological Sciences, University of Washington, Seattle, Washington 98195 FRED DUENNEBIER 4Hawaii Institute of Geophysics, University of Hawaii, Honolulu, Hawaii 96822 RODOLFO T. GUERRA 7Mobil Corporation, Box 900, Dallas, Texas 75221 CHRISTOPH H. J. HEMLEBEN 8Institut und Museum für Geologie und Paleontologie, Universitat Tubingen, Tubingen, Federal Republic of Germany DONALD HUSSONG 9Hawaii Institute of Geophysics, University of Hawaii, Honolulu, Hawaii 98195 MICHAEL S. MARLOW 10Marine Geology, U.S. Geological Survey, Menlo Park, California 94025 JAMES H. NATLAND 11Deep Sea Drilling Project, Scripps Institution of Oceanography, La Jolla, California 92093 CAROL J. PUDSEY 12Department of Geology and Mineralogy, University of Oxford, Oxford, United Kingdom G. W. RENZ 11Deep Sea Drilling Project, Scripps Institution of Oceanography, La Jolla, California 92093 MARC TARDY 13Laboratoire des Sciences de la Terre, Universite de Savoie, Chambery, France MARK E. WILLIS 14Department of Earth & Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 DOUGLAS WILSON 9Hawaii Institute of Geophysics, University of Hawaii, Honolulu, Hawaii 98195 AUDREY A. WRIGHT 1Earth Sciences and Center for Coastal Marine Studies, University of California, Santa Cruz, Santa Cruz, California 95064 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1982) 93 (11): 1065–1077. https://doi.org/10.1130/0016-7606(1982)93 2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation J. CASEY MOORE, BERNARD BIJU-DUVAL, JAMES A. BERGEN, GRANT BLACKINGTON, GEORGE E. CLAYPOOL, DARREL S. COWAN, FRED DUENNEBIER, RODOLFO T. GUERRA, CHRISTOPH H. J. HEMLEBEN, DONALD HUSSONG, MICHAEL S. MARLOW, JAMES H. NATLAND, CAROL J. PUDSEY, G. W. RENZ, MARC TARDY, MARK E. WILLIS, DOUGLAS WILSON, AUDREY A. WRIGHT; Offscraping and underthrusting of sediment at the deformation front of the Barbados Ridge: Deep Sea Drilling Project Leg 78A. GSA Bulletin 1982;; 93 (11): 1065–1077. doi: https://doi.org/10.1130/0016-7606(1982)93 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 On Leg 78A we drilled Sites 541 and 542 into the seaward edge of the Barbados Ridge complex, and Site 543 into the adjacent oceanic crust. The calcareous ooze, marls, and muds at Sites 541 and 542 are lithologically and paleontologically similar to the upper strata at Site 543 and are apparently offscraped from the down-going plate. A repetition of Miocene over Pliocene sediments at Site 541 documents major thrust or reverse faulting during offscraping. The hemipelagic to pelagic deposits offscraped in the Leg 78A area include no terrigenous sand beds, but they contain numerous Neogene ash layers derived from the Lesser Antilles Arc. Hence, this sequence is quite unlike the siliciclastic-dominated terranes on land that are inferred to be accretionary complexes.The structural fabric of the offscraped deposits at Sites 541 and 542 is disharmonic, probably along a décollement, with an underlying acoustically layered sequence, suggesting selective underthrusting of the latter. The acoustically layered sequence correlates seismically with pelagic strata cored at Site 543 on the incoming oceanic plate. Cores recovered from the possible décollement surface at both Sites 541 and 542 show scaly foliation and stratal disruption. Approximately lithostatic fluid pressure measured in the possible décollement zone probably facilitates the underthrusting of the pelagic sediments beneath the offscraped deposits. In the incoming section, a transition from smectitic to radiolarian mud with associated increases in density and strength probably controls the structural break between offscraped and underthrust strata. In the Leg 78A area, the underthrust pelagic section can be traced seismically at least 30 km arcward of the deformation front beneath the Barbados Ridge complex. 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.