doi:10.5194/bg-12-579-2015 © Author(s) 2015. CC Attribution 3.0 License. Lena River delta formation during the Holocene
Abstract. The Lena River delta, the largest delta of the Arc-tic Ocean, differs from other deltas because it consists mainly of organomineral sediments, commonly called peat, that con-tain a huge organic carbon reservoir. The analysis of delta sediment radiocarbon ages showed that they could not hav...
| Main Authors: | , , |
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| Format: | Text |
| Language: | English |
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2014
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.689.747 http://www.biogeosciences.net/12/579/2015/bg-12-579-2015.pdf |
| Summary: | Abstract. The Lena River delta, the largest delta of the Arc-tic Ocean, differs from other deltas because it consists mainly of organomineral sediments, commonly called peat, that con-tain 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 accu-mulated 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 com-posed of these sediments and other, more ancient islands were eroded. Each new sea transgression led to further ac-cumulation 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 al-lowed the periods of increasing (8000–6000 BP (years before present), 4500–4000, 2500–1500, and 400–200 BP) and de-creasing (5000, 3000, and 500 BP) Laptev Sea levels to be distinguished in the Lena Delta area. |
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