georefid:2013-013396SEDIS 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.epsl.2012.05.0342012-01-01publicationgeorefid:2013-013396doi:10.1016/j.epsl.2012.05.034Bailey, IanUniversity of Southampton, National Oceanography Centre Southampton, Southampton, United KingdomauthorFoster, Gavin L.University of Portsmouth, United KingdomauthorWilson, Paul A.Cardiff University, United KingdomauthorJovane, LuigiauthorStorey, Craig D.authorTrueman, Clive N.authorBecker, JuliaauthorElsevier, Amsterdam, NetherlandspublisherdocumentHardcopyEarth and Planetary Science Letters341-344222-233Relatively little is known in detail about the locations of the early Pleistocene ice-sheets responsible for ice-rafted debris (IRD) inputs to the sub-polar North Atlantic Ocean during intensification of northern hemisphere glaciation (iNHG). To shed new light on this problem, we present the first combined in-depth analysis of IRD flux and geochemical provenance of individual sand-sized IRD deposited in the sub-polar North Atlantic Ocean during the earliest large amplitude Pleistocene glacial, marine isotope stage (MIS) 100 ( approximately 2.52 Ma), arguably the key glacial during iNHG. IRD provenance is assessed using laser ablation lead (Pb) isotope analyses of single feldspar grains. We find that the Pb-isotope composition ( (super 206) Pb/ (super 204) Pb, (super 207) Pb/ (super 204) Pb and (super 208) Pb/ (super 204) Pb) of individual ice-rafted (>150mu m) feldspars deposited at DSDP Site 611A, ODP Site 981 and IODP Site U1308 during MIS 100 records a shift from predominantly Archaean-aged circum-North Atlantic Ocean continental sources during early glacial ice-rafting events to dominantly Palaeozoic and Proterozoic-aged sources during full glacial conditions. The distribution of feldspars in Pb-Pb space for full glacial MIS 100 more closely resembles that documented for feldspars deposited at the centre of the last glacial IRD belt (at IODP/DSDP Site U1308/609) during ambient (non-Heinrich-event) ice-rafting episodes of MIS 2 ( approximately 23.8 ka) than that documented for MIS 5d ( approximately 106 ka). Comparison of our early Pleistocene and last glacial cycle datasets suggests that MIS 100 was characterised by abundant iceberg calving from large ice-sheets on multiple continents in the high northern latitudes (not just on Greenland). Abstract Copyright (2012) Elsevier, B.V.completedQuaternary geologyAtlantic OceancalvingCenozoicDeep Sea Drilling ProjectdetritusDSDP Site 611Expedition 303Expeditions 303/306feldspar groupframework silicatesglacial geologyglaciationice raftingice sheetsicebergsIntegrated Ocean Drilling ProgramIODP Site U1308IPODisotopeslaser ablationlaser methodslast glacial maximumleadLeg 162Leg 94lower PleistocenemetalsMid-Atlantic RidgeNorth AtlanticNortheast AtlanticOcean Drilling ProgramODP Site 981PleistoceneprovenanceQuaternaryRockall Banksediment transportsilicatestransporturn:org.iodp:exp:303urnlargerWorkCitationcampaignurn:org.iodp:exp:162urnlargerWorkCitationcampaignurn:org.iodp:exp:94urnlargerWorkCitationcampaignurn:org.iodp:exp:94:site:611urnlargerWorkCitationstudyurn:org.iodp:exp:94urnlargerWorkCitationcampaignurn:org.iodp:exp:303:site:U1308urnlargerWorkCitationstudyurn:org.iodp:exp:303urnlargerWorkCitationcampaignurn:org.iodp:exp:162:site:981urnlargerWorkCitationstudyurn:org.iodp:exp:162urnlargerWorkCitationcampaignEnglishgeoscientificInformation-30.1906-14.390349.530055.2838Supplementary data available in online version