georefid:2003-063783SEDIS Publication Catalogue

ana.macario@awi.de

http://sedis.iodp.org/pub-catalogue/informationpointOfContact2011-06-23T00:00:00Zhttp://sedis.iodp.org/pub-catalogue/index.php?id=2003-0637832001-01-01publicationgeorefid:2003-063783Manatschal, GianretoETH Zuerich, Geologisches Institut, Zurich, Federal Republic of GermanyauthorFroitzheim, N.Southampton Oceanography Center, United KingdomauthorRubenach, M.University of Hawaii, United StatesauthorTurrin, B. D.University of Bonn, Federal Republic of GermanyauthorGeological Society of London, London, United KingdompublisherdocumentHardcopyIn: Wilson, R. C. L. (editor), Whitmarsh, R. B. (editor), Taylor, B. (editor), Froitzheim, N. (editor), Non-volcanic rifting of continental margins; a comparison of evidence from land and sea187405-428The Iberia Abyssal Plain segment of the West Iberia margin was drilled during Ocean Drilling Program Legs 149 and 173 and has been extensively studied geophysically. We present new microstructural investigations and new age data. These, together with observed distribution of upper- and lower-crustal and mantle rocks along the ocean-continent transition suggest the existence of three detachment faults, one of which was previously unrecognized. This information, together with a simple kinematic inversion of the reinterpreted seismic section Lusigal 12, allows discussion of the kinematic evolution of detachment faulting in terms of the temporal sequence of faulting, offset along individual faults, and thinning of the crust during faulting. Our study shows that the detachment structures recognized in the seismic profile became active only during a final stage of rifting when the crust was already considerably thinned to c. 12 km. The total amount of extension accommodated by the detachment faults is of the order of 32.6 km corresponding to a beta factor of about two. During rifting, the mode of deformation changed oceanwards. Initial listric faulting led to asymmetric basins, accommodating low amounts of extension, and was followed by a situation in which the footwall was pulled out from underneath a relatively stable hanging wall accommodating high amounts of extension. Deformation along the latter faults resulted in a conveyor-belt type sediment accumulation in which the exhumed footwall rocks were exposed, eroded and redeposited along the same active fault system.completedSolid-earth geophysicsAtlantic Oceancontinental crustcontinental margincrustdetachment faultsEast AtlanticEuropefaultsgeophysical methodsgeophysical surveysIberian abyssal plainIberian PeninsulaLeg 103Leg 149Leg 173North AtlanticNortheast AtlanticOcean Drilling Programoceanic crustODP Site 1067ODP Site 1070ODP Site 897passive marginsplate tectonicsPortugalseismic methodsSouthern EuropeSpainsurveystectonicsurn:org.iodp:exp:103urnlargerWorkCitationcampaignurn:org.iodp:exp:149urnlargerWorkCitationcampaignurn:org.iodp:exp:173urnlargerWorkCitationcampaignurn:org.iodp:exp:173:site:1067urnlargerWorkCitationstudyurn:org.iodp:exp:173urnlargerWorkCitationcampaignurn:org.iodp:exp:173:site:1070urnlargerWorkCitationstudyurn:org.iodp:exp:173urnlargerWorkCitationcampaignurn:org.iodp:exp:149:site:897urnlargerWorkCitationstudyurn:org.iodp:exp:149urnlargerWorkCitationcampaignEnglishgeoscientificInformation-12.4326-12.284740.474740.5019