georefid:1999-069722SEDIS 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=1999-0697221997-01-01publicationgeorefid:1999-069722Meggers, HelgeBremen University, Fachbereich Geowissenschaften, Bremen, Federal Republic of GermanyauthorBaumann, Karl-HeinzUniversity of London, United KingdomauthorThe Grzybowski Foundation, Cracow, PolandpublisherdocumentHardcopyIn: Hass, H. Christian (editor), Kaminski, Michael A. (editor), Contributions to the micropaleontology and paleoceanography of the northern North Atlantic539-50The calcium carbonate record, abundances and numbers of planktonic foraminifera and coccolithophorids, and the biometry of the foraminifera species Neogloboquadrina pachyderma sin. and Neogloboquadrina atlantica sin. from DSDP Site 552 have been analyzed for the time interval 3.2 Ma to 0.8 Ma. The different records are used to examine environmental changes in the North Atlantic, especially on the Rockall Plateau, and for comparison in the northern Labrador Sea (ODP Site 646). The planktonic assemblages in the late Pliocene consisted mainly of subpolar to temperate species; warm-water adapted species were relatively rare. The increase in the influence of polar surface water adapted species were relatively rare. The increase in the influence of polar surface waters at 2.5-2.4 Ma is indicated by an increase in the abundance of cold-water adapted coccolithophore Coccolithus pelagicus. However, this corresponds to an increase in sub-polar N. pachyderma dex., indicating that conditions during this "cold" phase would be analogous to intermittent interglacials of the late Pleistocene. Today's cold water-adapted N. pachyderma sin. first occurred at 1.8 Ma. Relatively high abundances during the interval 1.8-1.35 Ma seem to indicate relatively cold surface temperatures, whereas the absence of N. pachyderma sin. during the short interval 1.35-1.2 Ma probably indicates somewhat warmer surface water temperatures. However, using factor analysis, it is shown here that N. pachyderma sin. first showed a polar biogeographical distribution at 1.1 Ma, while it is a subpolar indicator between 1.8 Ma and 1.1 Ma. The biometric data of Neogloboquadrina tests at both sites indicate an evolutionary trend from large-sized N. atlantica sin. before 2.4 Ma via morphological integrade-forms (N. atlantica-pachyderma integrade") to small-sized N. pachyderma sin. between 1.8 Ma and 1.1 Ma.completedStratigraphyalgaeassemblagesAtlantic OceanbiogeographybiometryCenozoicclimate changeCoccolithophoraceaeDeep Sea Drilling ProjectDSDP Site 552factor analysisForaminiferaGlobigerinaceaInvertebrataIPODLabrador SeaLeg 105Leg 81marine environmentmorphologyNeogeneNeogloboquadrinaNeogloboquadrina atlanticaNeogloboquadrina pachydermaNorth AtlanticOcean Drilling ProgramODP Site 646paleo-oceanographypaleoclimatologypaleoecologypaleotemperatureplanktonic taxaPlantaePleistocenePlioceneProtistaQuaternaryRockall PlateauRotaliinastatistical analysisTertiarytestsupper Plioceneurn:org.iodp:exp:105urnlargerWorkCitationcampaignurn:org.iodp:exp:81urnlargerWorkCitationcampaignurn:org.iodp:exp:81:site:552urnlargerWorkCitationstudyurn:org.iodp:exp:81urnlargerWorkCitationcampaignurn:org.iodp:exp:105:site:646urnlargerWorkCitationstudyurn:org.iodp:exp:105urnlargerWorkCitationcampaignEnglishgeoscientificInformation-48.2206-23.132356.023358.1236