| Autor: |
Bauch, Henning A., Kassens, Heidemarie, Erlenkeuser, Helmut, Grootes, Pieter M., Thiede, Jörn |
| Předmět: |
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| Zdroj: |
Boreas; 5/10/99, Vol. 28 Issue 1, p194-204, 11p, 1 Chart, 9 Graphs, 1 Map |
| Abstrakt: |
The Holocene depositional setting of the Laptev Sea was studied using three marine sediment cores from water depths between 77 and 46 m. Based on sedimentary parameters (TOC content, δ[sup 13]C[sub org], sedimentation rates) controlled by radiocarbon age models the palaeoenvironment of a strongly coupled river-shelf system was reconstructed since ∼11 ka BP. Caused by a transgressing sea after the last glaciation, all cores reveal progressive decreases in sedimentation rates. Using the sedimentary records of a core from the Khatanga-Anabar river channel in the western Laptev Sea, several phases of change are recognized: (1) an early period lasted until ∼10 ka BP characterized by an increased deposition of plant debris due to shelf erosion and fluvial runoff; (2) a transitional phase with consistently increasing marine conditions until 6 ka BP, which was marked at its beginning near 10 ka BP by the first occurrence of marine bivalves, high TOC content and an increase in δ[sup 13]C[sub org]; (3) a time of extremely slow deposition of sediments, commencing at ∼6 ka BP and interpreted as Holocene sea-level highstand, which caused a southward retreat of the depositional centres within the now submerged river channels on the shelf; (4) a final phase with the establishment of modern conditions after ∼2 ka BP. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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