georefid:2012-056453SEDIS Publication Catalogue

ana.macario@awi.de

http://sedis.iodp.org/pub-catalogue/informationpointOfContact2013-07-08T00:00:00Zhttp://sedis.iodp.org/pub-catalogue/index.php?id=10.1016/j.palaeo.2012.02.0012012-01-01publicationgeorefid:2012-056453doi:10.1016/j.palaeo.2012.02.001Venti, Nicholas L.University of Delaware, College of Earth, Ocean, and Environment, Lewes, DE, United StatesauthorBillups, KatharinaauthorElsevier, Amsterdam, NetherlandspublisherdocumentHardcopyPalaeogeography, Palaeoclimatology, Palaeoecology326-32854-65From Ocean Drilling Program (ODP) Site 1208 on Shatsky Rise below the Kuroshio Current Extension, we present the North Pacific's first orbital-scale benthic-foraminiferal delta (super 18) O and delta (super 13) C time series to span the Pliocene-Pleistocene climate transition. Excellent agreement between the Site 1208 delta (super 18) O record and the global delta (super 18) O stack of Lisiecki and Raymo (2005) provides orbital-scale age control and confirms continuous stratigraphy from 3.7 to 1.8 Ma at the single-hole site. Cross-spectral analysis of the delta (super 18) O and delta (super 13) C time series reveals that these are coherent to 80% confidence at the 41-kyr obliquity band prior to 3.3 Ma (glacial isotope stage M2) and increase to the 95% level thereafter. Throughout, delta (super 18) O cycles consistently lead delta (super 13) C cycles by approximately 3 kyr. This suggests that global-ocean delta (super 13) C variations, as produced by terrestrial-marine (super 12) C transfers, were responsive to obliquity-induced climate changes before the Northern Hemisphere glaciations (NHG) reached mid latitudes at 2.7 Ma. In contrast, 41-kyr carbonate sedimentation (as derived from sediment reflectance) cycles, maxima tightly coupled to (>95% confidence) and in phase with minima in the delta (super 18) O record, do not emerge until 2.7 Ma. Foraminiferal fragmentation counts indicate that carbonate preservation is not the primary process behind enhanced carbonate deposition during interglacials. Thus, we surmise that hydrography-related changes in biogenic opal and carbonate production in surface water best explain glacial-interglacial carbonate cycles beginning with significant NHG. Firm establishment of orbital-scale age control on the stratigraphically complete Site 1208 section now provides a platform for high-resolution paleoceanographic reconstruction of the relatively understudied North Pacific. Abstract Copyright (2012) Elsevier, B.V.completedStratigraphybenthic taxabiostratigraphyC-13/C-12carbonCenozoicchemostratigraphyclimate changeForaminiferaglacial environmentglaciomarine environmentInvertebrataisotope ratiosisotopesLeg 198marine environmentmarine sedimentsmicrofossilsNeogeneNorth PacificNorthwest PacificO-18/O-16Ocean Drilling ProgramODP Site 1208oxygenPacific Oceanpaleo-oceanographypaleoclimatologypaleoecologyPleistocenePlioceneProtistaQuaternarysedimentsShatsky Risestable isotopesstatistical analysissubtropical environmentTertiarytime series analysisWest Pacificurn:org.iodp:exp:198urnlargerWorkCitationcampaignurn:org.iodp:exp:198:site:1208urnlargerWorkCitationstudyurn:org.iodp:exp:198urnlargerWorkCitationcampaignEnglishgeoscientificInformation158.1200158.120036.080036.0800