georefid:2006-091362SEDIS 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=10.1130/G23038A.12006-01-01publicationgeorefid:2006-091362doi:10.1130/G23038A.1Smart, Christopher W.University of Plymouth, School of Earth, Ocean and Environmental Sciences, Plymouth, United KingdomauthorThomas, EllenYale University, United StatesauthorGeological Society of America (GSA), Boulder, CO, United StatespublisherdocumentHardcopyGeology (Boulder)34 (12)1041-1044Small biserial foraminifera were abundant in the early Miocene (ca. 18.9-17.2 Ma) in the eastern Atlantic and western Indian Oceans, but absent in the western equatorial Atlantic Ocean, Weddell Sea, eastern Indian Ocean, and equatorial Pacific Ocean. They have been assigned to the benthic genus Bolivina, but their high abundances in sediments without evidence for dysoxia could not be explained. Apertural morphology, accumulation rates, and isotopic composition show that they were planktic (genus Streptochilus). Living Streptochilus are common in productive waters with intermittent upwelling. The widespread early Miocene high Streptochilus abundances may reflect vigorous but intermittent upwelling, inducing high phytoplankton growth rates. However, export production (estimated from benthic foraminiferal accumulation rates) was low, possibly due to high regeneration rates in a deep thermocline. The upwelled waters may have been an analog to Subantarctic Mode Waters, carrying nutrients into the eastern Atlantic and western Indian Oceans as the result of the initiation of a deep-reaching Antarctic Circumpolar Current, active Agulhas Leakage, and vigorous vertical mixing in the Southern Oceans.completedInvertebrate paleontologyStratigraphyAntarctic Circumpolar CurrentAtlantic Oceanbiserial taxaBolivinaBolivinitidaeBuliminaceaCenozoicclassificationForaminiferaInvertebrataLeg 208lower Miocenemarine environmentmarine sedimentsMiocenemodern analogsmorphologyNeogenenutrientsOcean Drilling ProgramODP Site 1264ODP Site 1265paleo-oceanographypaleocirculationpaleoecologyplanktonic taxaproductivityProtistaRotaliinasedimentation ratessedimentsSouth AtlanticStreptochilustaxonomyTertiarythermoclineupwellingWalvis Ridgeurn:org.iodp:exp:208urnlargerWorkCitationcampaignurn:org.iodp:exp:208:site:1264urnlargerWorkCitationstudyurn:org.iodp:exp:208urnlargerWorkCitationcampaignurn:org.iodp:exp:208:site:1265urnlargerWorkCitationstudyurn:org.iodp:exp:208urnlargerWorkCitationcampaignEnglishgeoscientificInformation2.38002.5100-28.5000-28.3200With GSA Data Repository Item 2006227