georefid:2007-111274SEDIS 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=10.1111/j.1365-246X.2007.03450.x2007-01-01publicationgeorefid:2007-111274doi:10.1111/j.1365-246X.2007.03450.xGaina, CarmenGeological Survey of Norway, Center for Geodynamics, Trondheim, NorwayauthorMueller, R. DietmarUniversity of Sydney, AustraliaauthorBrown, BelindaNational Institute of Advanced Industrial Science and Technology, JapanauthorIshihara, TakemiPolar Marine Geophysical Research Expedition, Russian FederationauthorIvanov, SergeyauthorBlackwell Science for the Royal Astronomical Society, the Deutsche Geophysikalische Gesellschaft and the European Geophysical Society, InternationalpublisherdocumentHardcopyGeophysical Journal International170 (1)151-169We present a tectonic interpretation of the breakup and early seafloor spreading between India and Antarctica based on improved coverage of potential field and seismic data off the east Antarctic margin between the Gunnerus Ridge and the Bruce Rise. We have identified a series of ENE trending Mesozoic magnetic anomalies from chron M9o to M2o in the Enderby Basin, and M9o to M4o in the Princess Elizabeth Trough and Davis Sea Basin, indicating that India-Antarctica and India-Australia breakups were roughly contemporaneous. We present evidence for an abandoned spreading centre south of the Elan Bank microcontinent; the estimated timing of its extinction corresponds to the early surface expression of the Kerguelen Plume at the Southern Kerguelen Plateau around 120 Ma. We observe an increase in spreading rate from west to east, between chron M9 and M4, along the Antarctic margin and suggest the tectono-magmatic segmentation of oceanic crust has been influenced by inherited crustal structure, the kinematics of Gondwanaland breakup and the proximity to the Kerguelen hotspot. A high-amplitude, E-W oriented magnetic lineation named the Mac Robertson Coast Anomaly (MCA), coinciding with a landwards step-down in basement observed in seismic reflection data, is tentatively interpreted as the boundary between continental/transitional zone and oceanic crust. (mod. journ. abst.)completedSolid-earth geophysicsApplied geophysicsAntarcticacontinental marginCretaceousCrozet BasinDavis Seaelastic wavesEnderby Basingeophysical methodsgeophysical profilesgeophysical surveysGondwanagravity fieldhot spotsIndian OceanIndian Ocean IslandsIndian PlateKerguelen IslandsLeg 183MacRobertson Coastmagnetic anomaliesmantlemantle plumesMesozoicmid-ocean ridgesOcean Drilling Programocean floorsODP Site 1137plate tectonicspotential fieldremote sensingsatellite methodssea-floor spreadingseismic methodsseismic profilesseismic wavesSouthern OceanSouthwest Indian Ridgespreading centerssurveysurn:org.iodp:exp:183urnlargerWorkCitationcampaignurn:org.iodp:exp:183:site:1137urnlargerWorkCitationstudyurn:org.iodp:exp:183urnlargerWorkCitationcampaignEnglishgeoscientificInformation68.053668.0536-56.5000-56.5000