Structure and composition of Late Quaternary permafrost sequences at Cape Mamontov Klyk, Northern Siberia, and the palaeoenvironmental and palaeoclimate implications
Research at Cape Mamontov Klyk, Northern Siberia, was carried out to reconstruct the palaeoclimatic and palaeoenvironmentalhistory in this remote region. The investigated area is located in the Lena-Anabar lowland at the LaptevSea coast. Generally, the cliff of Cape Mamontovy Klyk (73° 36? N; 117° 1...
| Main Authors: | , , , , |
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| Format: | Conference Object |
| Language: | unknown |
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2005
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| Subjects: | |
| Online Access: | https://epic.awi.de/id/eprint/12896/ https://hdl.handle.net/10013/epic.23301 |
| Summary: | Research at Cape Mamontov Klyk, Northern Siberia, was carried out to reconstruct the palaeoclimatic and palaeoenvironmentalhistory in this remote region. The investigated area is located in the Lena-Anabar lowland at the LaptevSea coast. Generally, the cliff of Cape Mamontovy Klyk (73° 36? N; 117° 10? E) consists of ice-rich sediments witha complicated depositionary and cryolithological situation.Samples of sediments and ice wedges of different generations were taken over the whole vertical profile of the cliff forsedimentological, hydrochemical and isotope-geochemical analyses. These include analyses of grain size, and C andN content in order to get information about the conditions of deposition. With the ice wedge samples hydrochemicalanalyses (major ions) and Æ18O and ÆD analyses were carried out for information about hydrological and palaeoclimaticconditions. A clear stratification of four units outcropping at the cliff can be found regarding the differentsedimentological parameters. About 4 m thick bottom sands with ice-sand-wedges represent the oldest unit in thissection (IRSL dated between 31:34:2 and 56:26:7 ka). It is overlain by a 5 m thick peat-sand-complexwith smallice wedges radiocarbon dated 30 to 45 ka 14C BP. Above that the Late Pleistocene Ice Complex as the main unit (about9 to 20 m thick) is one of the most peculiar cryolithological formations in this region characterised by silty sands withhuge syngenetic ice wedges. The Ice Complex is partly covered by a 2 m thick horizon of peat-rich, silty sedimentsof Holocene age. Besides this, two more subunits of Holocene age can be distinguished: deposits of thermoerosionalvalleys as well as fluvial deposits. First interpretations of these units indicate changing depositionary conditions froma rather fluvial to an alluvial environment in the Pleistocene and thermoerosional destruction in the Holocene.Recent ice wedges of the profile seem to be genetically correlated with snow patches as their isotopic composition isin the same range. Ice wedge growth ... |
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