DOI: 10.1016/j.palaeo.2016.11.021
论文题名: Paleoceanographic changes in the Northeast Indian Ocean during middle Miocene inferred from carbon and oxygen isotopes of foraminiferal fossil shells
作者: Banerjee B. ; Ahmad S.M. ; Raza W. ; Raza T.
刊名: Palaeogeography, Palaeoclimatology, Palaeoecology
ISSN: 0031-0182
出版年: 2017
卷: 466 起始页码: 166
结束页码: 173
语种: 英语
英文关键词: Foraminifera
; Indian summer monsoon
; Mid Miocene climatic optimum
; Monterey excursion
; North Atlantic deep water
; δ13C
; δ18O
英文摘要: The middle Miocene transition witnessed rapid fluctuations in oceanographic and climatic systems. However, very limited work has been attempted in Miocene sediments of the Northern Indian Ocean to identify these changes. Here we present the first detailed δ13C and δ18O records of surface and deep dwelling foraminifera from ODP site 758 in the Northeast Indian Ocean, located atop the Ninetyeast Ridge. Carbon and oxygen isotopic data on Globigerinoides quadrilobatus (planktonic) and Cibicidoides wuellerstorfi (benthic foraminifera) indicated various global and local successions of oceanographic and climatic importance. The climatic events recorded at ODP 758 are; (a) Mid Miocene climatic Optimum (17–15 Ma), (b) Monterey excursion (17–14 Ma), (c) East Antarctica Ice sheet formation (13.8 Ma), (d) Initiation of Indian Summer Monsoon with waning of Antarctica Ice sheet (12.3–10.4 Ma), and (e) evidence of a cooling event (10.2–9.6 Ma). Our benthic foraminifera δ18O record showed almost identical deep water evolution to that of the Indo Pacific for 13.9–11.5 Ma interval. A significant decrease in δ13Cben at ~ 10.2 Ma was indicative of a complete re-adjustment of the carbon cycle after the Monterey excursion and export of the North Atlantic Deep Water (NADW) towards the southern Ocean to give rise to the Circumpolar Deep Water (CDW), with a δ13C value of ~ 0.4‰. The formation of the NADW had given rise to modern deep water like conditions at ~ 10 Ma ago. A comparison of our record with previously published isotopic records from other regions suggested a good correlation between the South Pacific, Indo Pacific and Northeast Indian Ocean during the studied time interval. It appears that a strong westerly Indian Ocean current (MIOjet) may have linked these Oceans from 14 to 9 Ma. © 2016 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/68036
Appears in Collections: 过去全球变化的重建
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作者单位: Academy of Scientific and Innovative Research (AcSIR), CSIR-National Geophysical Research Institute, Uppal Road, Hyderabad, India; CSIR- National Geophysical Research Institute, Uppal Road, Hyderabad, India
Recommended Citation:
Banerjee B.,Ahmad S.M.,Raza W.,et al. Paleoceanographic changes in the Northeast Indian Ocean during middle Miocene inferred from carbon and oxygen isotopes of foraminiferal fossil shells[J]. Palaeogeography, Palaeoclimatology, Palaeoecology,2017-01-01,466