georefid:2012-007667SEDIS 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=10.1130/G32454.12011-01-01publicationgeorefid:2012-007667doi:10.1130/G32454.1Romero, O. E.Universidad de Granada, Instituto Andaluz de Ciencias de la Tierra, Granada, SpainauthorSwann, G. E. A.University of Nottingham, United KingdomauthorHodell, D. A.University of Cambridge, United KingdomauthorHelmke, P.Federal Institute of Hydrology, GermanyauthorRey, D.Universidad de Vigo, SpainauthorRubio, B.authorGeological Society of America (GSA), Boulder, CO, United StatespublisherdocumentHardcopyGeology (Boulder)39 (11)1015-1018The Last Interglacial (LIG), corresponding to Marine Isotope Stage (MIS) 5e, provides a reference of interglacial climate variability in the absence of anthropogenic forcing. Using an expanded section of the LIG gained at Integrated Ocean Drilling Program Site U1304 in the Subarctic Atlantic, we demonstrate that the early MIS 5e was marked by oceanographic conditions conducive for high diatom production and accumulation. The appearance of diatom-dominated laminated oozes approximately 3 k.y. after the beginning of MIS 5e at ca. 125 ka coincides with a shift to higher delta (super 30) Si (sub diat) values together with the dominance of Thalassiothrix longissima, indicative of increased nutrient availability and silicic acid utilization in surface waters. Though the Subarctic Front provided the physical conditions for high diatom production and deposition, these processes alone are insufficient to explain the high rates of siliceous productivity and the formation of diatomaceous sediments. Instead, the additional presence of an increased nutrient pool provided by Subantarctic Mode Water played the decisive role in initiating and sustaining diatom production. The high diatom productivity and the occurrence of diatomaceous sediments in the late Quaternary challenge the current hypothesis of a silica-depleted North Atlantic during the LIG.completedQuaternary geologyalgaeAtlantic Oceanbioclastic sedimentationCenozoicclastic sedimentsclimate changediatomsExpedition 303Expeditions 303/306Integrated Ocean Drilling Programinterglacial environmentIODP Site U1304marine sedimentsmicrofossilsMIS 5eNorth AtlanticNortheast Atlanticnutrientsocean circulationoozepaleo-oceanographypaleoclimatologypaleoecologyPlantaeproductivityQuaternarysedimentationsedimentsSubantarctic Mode Watersubarctic regionsupper Quaternaryurn:org.iodp:exp:303urnlargerWorkCitationcampaignurn:org.iodp:exp:303:site:U1304urnlargerWorkCitationstudyurn:org.iodp:exp:303urnlargerWorkCitationcampaignEnglishgeoscientificInformation-33.3200-33.320053.030053.0300With GSA Data Repository Item 2011301