Mass movement deposits in the 3.6 Ma sediment record of Lake El'gygytgyn, Far East Russian Arctic
| Autor: | Volker Wennrich, A.C. Gebhardt, Norbert R Nowaczyk, Martin Melles, M. A. Sauerbrey, O. Juschus |
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| Rok vydání: | 2013 |
| Předmět: |
010506 paleontology
Mass movement lcsh:Environmental protection Stratigraphy Geochemistry 550 - Earth sciences 010502 geochemistry & geophysics 01 natural sciences Debris flow lcsh:Environmental pollution lcsh:TD169-171.8 14. Life underwater Geomorphology lcsh:Environmental sciences 0105 earth and related environmental sciences lcsh:GE1-350 Global and Planetary Change Paleontology Sediment Turbidite Arctic 13. Climate action lcsh:TD172-193.5 Facies Quaternary Far East Geology |
| Zdroj: | Climate of the Past, Vol 9, Iss 4, Pp 1949-1967 (2013) Climate of the Past EPIC3Climate of the Past, 9(4), pp. 1949-1967, ISSN: 1814-9332 |
| ISSN: | 1814-9332 |
| DOI: | 10.5194/cp-9-1949-2013 |
| Popis: | This paper focuses on the characterization and genesis of mass movement deposits (MMDs) in the Quaternary and Pliocene sediments of Lake El'gygytgyn, Far East Russian Arctic. Three partly overlapping holes were drilled into the 320 m long sediment record at International Continental Scientific Drilling Program (ICDP) Site 5011-1 in the lake basin, recovering the Quaternary almost completely, and the Pliocene down to 3.6 Ma with 52% recovery. Mass movement deposits were investigated in all three cores, based on macroscopical core descriptions, radiographic images, high-resolution magnetic susceptibility and gamma-ray density. Five different types of MMDs were identified: turbidites, grain-flow deposits, debrites, slumps and slides. These are formed by transitional mass movement processes, and thus can be co-generic. An initial slope failure is thought to transform into a debris flow that deforms frontal sediments, partly disintegrates and dilutes into a turbidity flow. Turbidites are by far the most frequent MMD type in the lake center. They occur throughout the record in all pelagic sedimentary facies, but they are thinner in facies formed during cold climate conditions. All other MMDs, by contrast, incise exclusively the pelagic facies deposited during warm climates. In the 123 m thick Quaternary composite sediment record 230 mass movement events are identified, comprising 33% of the sediment length. Turbidites contribute 93% of the number of Quaternary MMDs, but only 35% of their thickness. In the Pliocene sediments between 123 and 320 m, 181 additional mass movement deposits are identified, which constitute ~33% of the recovered sediments. The mean recurrence interval for MMDs is 11 and 5 ka in the Quaternary and Pliocene, respectively. |
| Databáze: | OpenAIRE |
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