Show simple item record

dc.contributor.authorPattan, J.N.
dc.contributor.authorParthiban, G.
dc.contributor.authorGarg, A.
dc.contributor.authorMoraes, N.R.C.
dc.date.accessioned2018-06-06
dc.date.accessioned2018-10-23T09:24:59Z
dc.date.available2017-06-01
dc.date.available2018-10-23T09:24:59Z
dc.date.issued2017
dc.identifier.citationMarine and Petroleum Geology, vol.84; 2017; 243-256
dc.identifier.issn0264-8172
dc.identifier.urihttps://doi.org/10.1016/J.MARPETGEO.2017.03.034
dc.identifier.urihttp://drs.nio.org/drs/handle/2264/7850
dc.description.abstractTwo sediment cores, ABP-32/GC-01R and ABP-32/GC-03 were collected at a water depth of 642 m and 1086 m off Goa from the present day Oxygen Minimum Zone (OMZ) of eastern Arabian Sea (EAS) cover time span of last 18 ka and 32 ka respectively were analysed for multi-proxy redox-sensitive elements to understand the variation in the redox conditions and factors responsible for its development. Redox-sensitive elements concentration and their normalized ratios (Mn/Al, U/Th, Mo/Al and Ce/Ce*) suggest that sediment core ABP-32/GC-01R is under more reducing conditions due to its location within the centre of OMZ compared to core ABP-32/GC-03 which is at the base of OMZ. Sediments from the EAS are of non-euxinic environments where dissolved sulfide is present but restricted to the sediment pore-waters. Lack of significant correlation (r=< 0.1) of organic carbon with U and Mo suggest that productivity may not have control on the development of reducing conditions. The lowest Mn/Al ratio, strong negative Ce/Ce* anomaly and remarkable enrichment of U/Th and Mo/Al ratios during the last deglaciation, and Heinrich events (H1, H2, H3) indicate intense reducing conditions probably due to poor ventilation by oxygen depleted bottom waters from Subantarctic Mode Waters (SAMW) - Antarctic Intermediate waters (AAIW). There is a distinct lathanide fractionation in the sediment cores where, La(n)/Yb(n) ratio is <1, ?1 and >1 during the last 10 ka (Holocene), 14-10 ka (includes-Younger Dryas and B?lling-Aller?d), 18-14 ka (last deglaciation) and Heinrich events suggesting less reducing, terrigenous dominated and intense reducing condition respectively.
dc.language.isoen
dc.publisherElsevier
dc.relation.ispartofMar Pet Geol
dc.relation.isreferencedbySCI
dc.titleIntense reducing conditions during the last deglaciation and Heinrich events (H1, H2, H3) in sediments from the oxygen minimum zone off Goa, eastern Arabian Sea
dc.typeJournal Article
dc.affiliation.authorCSIR-National Institute of Oceanography, Dona Paula, Goa, India


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record