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dc.contributor.authorNath, B.N.
dc.contributor.authorSijinkumar, A.V.
dc.contributor.authorBorole, D.V.
dc.contributor.authorGupta, S.M.
dc.contributor.authorMergulhao, L.P.
dc.contributor.authorMascarenhas-Pereira, M.B.L.
dc.contributor.authorRamaswamy, V.
dc.contributor.authorGuptha, M.V.S.
dc.contributor.authorPossnert, G.
dc.contributor.authorAldahan, A.
dc.contributor.authorKhadge, N.H.
dc.contributor.authorSharma, R.
dc.date.accessioned2013-08-07T12:22:45Z
dc.date.available2013-08-07T12:22:45Z
dc.date.issued2013
dc.identifier.citationBoreas, vol.42(3); 2013; 762-778
dc.identifier.otherno
dc.identifier.urihttp://drs.nio.org/drs/handle/2264/4343
dc.description.abstractIn the present investigation, an age model of carbonate-rich cores from a seamount top in the Central Indian Basin (CIB) was constructed using both isotopic (sup(230)Th sub(excess), AMS sup(14)C, oxygen isotopes) and biostratigraphic methods. The chronologies using the two methods are in good agreement, yielding a record of the late Middle Pleistocene to the Pleistocene-Holocene transition (550 to 11.5ka). The first appearance datum (FAD) of the radiolarian Buccinosphaera invaginata (180ka) and coccolith Emiliania huxleyi (268ka) and the last appearance datum (LAD) of the radiolarian Stylatractus universus (425ka) were used. A monsoon-induced productivity increase was inferred from carbonate, organic carbon and delta sup(13)C records in response to the Mid-Brunhes Climatic Shift (MBCS), consistent with an increased global productivity. While the coccolith diversity increased, a decrease in coccolith productivity was found during the MBCS. At nearly the same time period, earlier records from the equatorial Indian Ocean, western Indian Ocean and eastern Africa have shown an increased productivity in response to the influence of westerlies and increased monsoon. The influence of easterlies from Australia and the intensification of aridity are evidenced by increased kaolinite content and clay-sized sediments in response to the MBCS. An increased abundance of Globorotalia menardii and other resistant species beginning from marine isotope stage (MIS) 11 and the proliferation of coccolith Gephyrocapsa spp. indicate increased dissolution, which is consistent with the widespread global carbonate dissolution during this period. The relatively high carbonate dissolution during the transition period of MIS 3/2 and glacial to interglacial periods (MIS 6, 7 and 8) may be due to the enhanced flow of corrosive Antarctic Bottom Water (AABW) into the CIB.
dc.language.isoen
dc.publisherJohn Wiley
dc.relation.requiresBoreas_42_762.jpg
dc.rights© 2012 The Authors
dc.subjectcarbonates
dc.subjectorganic carbon
dc.subjectmonsoons
dc.subjectproductivity
dc.subjectseamounts
dc.subjectoxygen isotope stratigraphy
dc.titleRecord of carbonate preservation and the Mid-Brunhes climatic shift from a seamount top with low sedimentation rates in the Central Indian Basin
dc.typeJournal Article


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