georefid:2012-051960SEDIS 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.2011.11.0262012-01-01publicationgeorefid:2012-051960doi:10.1016/j.epsl.2011.11.026Naafs, B. David A.Alfred Wegener Institute for Polar and Marine Research, Department of Marine Geology and Paleontology, Bremerhaven, GermanyauthorHefter, JensPotsdam University, GermanyauthorActon, GaryUniversity of California, Davis, United StatesauthorHaug, Gerald H.University of Bristol, United KingdomauthorMartinez-Garcia, AlfredoauthorPancost, RichardauthorStein, RuedigerauthorElsevier, Amsterdam, NetherlandspublisherdocumentHardcopyEarth and Planetary Science Letters317-3188-19Here we present orbitally-resolved records of terrestrial higher plant leaf wax input to the North Atlantic over the last 3.5 Ma, based on the accumulation of long-chain n-alkanes and n-alkanl-1-ols at IODP Site U1313. These lipids are a major component of dust, even in remote ocean areas, and have a predominantly aeolian origin in distal marine sediments. Our results demonstrate that around 2.7 million years ago (Ma), coinciding with the intensification of the Northern Hemisphere glaciation (NHG), the aeolian input of terrestrial material to the North Atlantic increased drastically. Since then, during every glacial the aeolian input of higher plant material was up to 30 times higher than during interglacials. The close correspondence between aeolian input to the North Atlantic and other dust records indicates a globally uniform response of dust sources to Quaternary climate variability, although the amplitude of variation differs among areas. We argue that the increased aeolian input at Site U1313 during glacials is predominantly related to the episodic appearance of continental ice sheets in North America and the associated strengthening of glaciogenic dust sources. Evolutional spectral analyses of the n-alkane records were therefore used to determine the dominant astronomical forcing in North American ice sheet advances. These results demonstrate that during the early Pleistocene North American ice sheet dynamics responded predominantly to variations in obliquity (41 ka), which argues against previous suggestions of precession-related variations in Northern Hemisphere ice sheets during the early Pleistocene. Abstract Copyright (2012) Elsevier, B.V.completedStratigraphySedimentary petrologyaliphatic hydrocarbonsalkanesAtlantic OceanbiomarkersC-13/C-12carbonCenozoicclastic sedimentsdustExpedition 306Expeditions 303/306glacial geologyglaciationhydrocarbonsice sheetsIntegrated Ocean Drilling ProgramIODP Site U1313isotope ratiosisotopesleaveslipidsmarine sedimentsmass spectraMid-Atlantic RidgeMilankovitch theoryn-alkanesNeogeneNorth AmericaNorth Atlanticobliquity of the eclipticorganic compoundspaleoclimatologyPlantaePleistocenePlioceneprecessionprovenanceQuaternarysedimentsspectrastable isotopesterrestrial environmentTertiarytransportupper Pliocenewaxeswind transporturn:org.iodp:exp:306urnlargerWorkCitationcampaignurn:org.iodp:exp:306:site:U1313urnlargerWorkCitationstudyurn:org.iodp:exp:306urnlargerWorkCitationcampaignEnglishgeoscientificInformation-32.5700-32.570041.000041.0000Supplementary data available in online version