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Biogeosciences An interactive open-access journal of the European Geosciences Union
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Volume 12, issue 2
Biogeosciences, 12, 579–593, 2015
https://doi.org/10.5194/bg-12-579-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.

Special issue: Interactions between the land and sea in the Lena Delta...

Biogeosciences, 12, 579–593, 2015
https://doi.org/10.5194/bg-12-579-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 29 Jan 2015

Research article | 29 Jan 2015

Lena River delta formation during the Holocene

D. Bolshiyanov1,2, A. Makarov1,2, and L. Savelieva2 D. Bolshiyanov et al.
  • 1State Research Center, Arctic and Antarctic Research Institute, St.Petersburg, Russia
  • 2St.Petersburg State University, St.Petersburg, Russia

Abstract. The Lena River delta, the largest delta of the Arctic Ocean, differs from other deltas because it consists mainly of organomineral sediments, commonly called peat, that contain a huge organic carbon reservoir. The analysis of delta sediment radiocarbon ages showed that they could not have formed as peat during floodplain bogging; rather, they accumulated when Laptev Sea water level was high and green mosses and sedges grew and were deposited on the surface of flooded marshes.

The Lena River delta formed as organomineral masses and layered sediments accumulated during transgressive phases when sea level rose. In regressive phases, the islands composed of these sediments and other, more ancient islands were eroded. Each new sea transgression led to further accumulation of layered sediments. As a result of alternating transgressive and regressive phases, the first alluvial-marine terrace formed, consisting of geological bodies of different ages. Determining the formation age of different areas of the first terrace and other marine terraces on the coast allowed the periods of increasing (8000–6000 BP (years before present), 4500–4000, 2500–1500, and 400–200 BP) and decreasing (5000, 3000, and 500 BP) Laptev Sea levels to be distinguished in the Lena Delta area.

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