論文

査読有り
2021年12月13日

Palaeoredox reconstruction in the eastern Arabian Sea since the late Miocene: Insights from trace elements and stable isotopes of molybdenum (δ98/95Mo) and tungsten (δ186/184W) at IODP Site U1457 of Laxmi Basin

Palaeogeography, Palaeoclimatology, Palaeoecology
  • M. Alam
  • ,
  • M. Tripti
  • ,
  • G. P. Gurumurthy
  • ,
  • Y. Sohrin
  • ,
  • M. Tsujisaka
  • ,
  • A. D. Singh
  • ,
  • S. Takano
  • ,
  • K. Verma

587
開始ページ
110790
終了ページ
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1016/j.palaeo.2021.110790

The present study investigates the oxygenation history of the northeastern Arabian Sea since the late Miocene using redox sensitive elemental and metal stable isotopic signatures in the deep-sea sediments. To achieve this, the sediment core samples collected at Site U1457 (67°55.80′E, 17°9.95′N, water depth 3534 m) of Laxmi Basin in the northeastern Arabian Sea during the International Ocean Discovery Program (IODP) Expedition 355 were analysed for a suite of elemental (Mo, W, U, V, Ba, Cd and P) and stable molybdenum (Mo) isotope (δ98/95Mo relative to NIST SRM 3134 lot No. 130418) as well as stable tungsten (W) isotope (δ186/184W relative to NIST SRM 3163 lot No. 080331) composition. Sedimentary δ98/95Mo values (−0.70‰ to +1.18‰) at IODP Site U1457 in the northeastern Arabian Sea indicated partial authigenic Mo component. In contrast, the sedimentary δ186/184W values (−0.02‰ to +0.21‰) were in the range similar to that of lithogenous material suggesting dominance of detrital composition. The study reveals that the water column in the eastern Arabian Sea was oxic during the late Miocene and Pliocene while oxic to suboxic condition prevailed during the Pleistocene. The study also explores that under oxic to suboxic condition with limited particle shuttling, the W isotopes do not undergo significant fractionation, and their isotope ratios reflect the detrital source signature. This study reports the first results on isotopic compositions of Mo and W in sediments of the northeastern Arabian Sea since the late Miocene to investigate the palaeoredox conditions on a million-year time scale.

リンク情報
DOI
https://doi.org/10.1016/j.palaeo.2021.110790
Scopus
https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85121307366&origin=inward
Scopus Citedby
https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85121307366&origin=inward
ID情報
  • DOI : 10.1016/j.palaeo.2021.110790
  • ISSN : 0031-0182
  • SCOPUS ID : 85121307366

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