georefid:2006-010628SEDIS 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=2006-0106282005-01-01publicationgeorefid:2006-010628Underwood, Michael B.University of Missouri, Department of Geological Sciences, Columbia, MO, United StatesauthorFergusson, Christopher L.University of Wollongong, AustraliaauthorGeological Society of London, London, United KingdompublisherdocumentHardcopyIn: Hodgson, David M. (editor), Flint, Stephen S. (editor), Submarine slope systems; processes and products244113-129Submarine slope systems in subduction zones evolve in response to a combination of tectonic and sedimentary forcing. It can be difficult to determine how and when tectonic forcing affects sedimentation, especially when investigating ancient rock successions, but one of the more reliable indicators is a change in sediment composition. During Leg 190 of the Ocean Drilling Program, sandy turbidites were recovered from a Quaternary trench wedge (Nankai Trough), a Pliocene-Pleistocene slope basin, the underlying Pliocene-Miocene accretionary prism, and a Miocene turbidite facies in the Shikoku Basin. Differences in detrital provenance between the sand and clay-sized fractions indicate that turbidity currents did not follow pathways of suspended-sediment transport during the past 10 Ma. During the middle and late Miocene, the sand probably was eroded from a newly exposed accretionary complex (Shimanto Belt). In contrast, high contents of detrital smectite in Miocene mudstones (>50 wt% of the <2 mu m size fraction, relative to illite, chlorite+kaolinite, and quartz) point to a strong volcanic component of suspended-sediment input (Izu-Bonin island arc). The sand in accreted Pliocene turbidites was also eroded from the Shimanto Belt and transported by transverse flow down the insular slope. The trench-wedge facies then switched to axial flow during the Quaternary, when the sand supply tapped a mixed volcanic-metasedimentary provenance in the rapidly uplifted Izu-Honshu collision zone. Progressive depletion of smectite during the Pliocene and Pleistocene (<20 wt%) points to increased movement of illite-and chlorite-rich clay toward the east and NE from sources on Kyushu and Shikoku. That shift in mud composition coincides with intensification of the North Pacific western boundary current (Kuroshio Current) at approximately 3 Ma. Overall, the depositional system in the Nankai Trough and Shikoku Basin shifted its sand sources because of regional tectonics, whereas the suspended-sediment budget was modulated by hemispheric changes in ocean-water circulation.completedStratigraphyStructural geologybathymetryCenozoicchemical ratiosclastic rocksclay mineralogyclay mineralsDeep Sea Drilling Projectdepositional environmentDSDP Site 582DSDP Site 583grain sizeIPODLeg 190Leg 87marine environmentmetamorphic rocksmetasedimentary rocksmineral compositionNankai TroughNeogeneNorth PacificNorthwest PacificOcean Drilling ProgramODP Site 1174ODP Site 1175ODP Site 1176ODP Site 1177ODP Site 1178Pacific Oceanpaleo-oceanographyPleistocenePlioceneQuaternarysandstonesedimentary rockssheet silicatesShikoku Basinsilicatesslope environmentsmectitesubduction zonestectonicsTertiarytrench-slope systemturbiditeupper CenozoicWest Pacificurn:org.iodp:exp:190urnlargerWorkCitationcampaignurn:org.iodp:exp:87urnlargerWorkCitationcampaignurn:org.iodp:exp:87:site:582urnlargerWorkCitationstudyurn:org.iodp:exp:87urnlargerWorkCitationcampaignurn:org.iodp:exp:87:site:583urnlargerWorkCitationstudyurn:org.iodp:exp:87urnlargerWorkCitationcampaignurn:org.iodp:exp:190:site:1174urnlargerWorkCitationstudyurn:org.iodp:exp:190urnlargerWorkCitationcampaignurn:org.iodp:exp:190:site:1175urnlargerWorkCitationstudyurn:org.iodp:exp:190urnlargerWorkCitationcampaignurn:org.iodp:exp:190:site:1176urnlargerWorkCitationstudyurn:org.iodp:exp:190urnlargerWorkCitationcampaignurn:org.iodp:exp:190:site:1177urnlargerWorkCitationstudyurn:org.iodp:exp:190urnlargerWorkCitationcampaignurn:org.iodp:exp:190:site:1178urnlargerWorkCitationstudyurn:org.iodp:exp:190urnlargerWorkCitationcampaignEnglishgeoscientificInformation132.0000140.000030.000036.0000