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      Permanent link:
      https://www.ias.ac.in/article/fulltext/jess/128/01/0015

    • Keywords

       

      Environmental change; stable isotopes; C/N ratios; Red River delta; Vietnam.

    • Abstract

       

      The present study applied stable carbon isotopes, C/N ratios, and sedimentological indicators to reconstruct environmental changes during Holocene and to test the hypothesis that $\delta^{13}$C and C/N ratios are accurate proxies of sea level change in the Red River delta (RRD), Vietnam. A 36 m long sediment core was mechanically drilled in the wave-dominated region of the RRD. The covariation of lithological characteristics, sediment grain-size distribution and geochemical proxies (LOI, TOC, C/N, $\delta^{13}$C) suggested that the sediment core could be divided into six depositional environments, consisting of sub- and inter-tidal flats (formed before 8860 cal. year BP), shelf-prodelta, delta front slope (formed from 8860 to 2290 cal. year BP), delta front platform, tidal flat, and flood plain (from 2290 to 0 cal. year BP). Covariation of $\delta^{13}$C and C/N ratios in the sediment core allowed for tracing the origin of sedimentary organic carbon, which shifted from the dominance of mangroves and C3 plants at the sub- and inter-tidal flats to marine phytoplankton at the shelf-prodelta and delta front slope. The sedimentary sources of the delta front platform, tidal flat and flood plain were a mixture of phytoplankton and C3 plants, with the later source being dominant.

    • Author Affiliations

       

      Nguyen Tai Tue1 2 Dang Minh Quan2 Pham Thao Nguyen2 Luu Viet Dung2 Tran Dang Quy1 2 Mai Trong Nhuan1 2

      1. Faculty of Geology, VNU University of Science, 334 Nguyen Trai Street, Thanh Xuan, Hanoi, Vietnam.
      2. VNU Key Laboratory of Geoenvironment and Climate Change Response, 334 Nguyen Trai Street, Thanh Xuan, Hanoi, Vietnam.
    • Dates

       
  • Journal of Earth System Science | News

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