Depositional environment of the Laptev Sea (Arctic Siberia) during the Holocene

• Published in: Boreas
• Main Authors: BAUCH, HENNING A., KASSENS, HEIDEMARIE, ERLENKEUSER, HELMUT, GROOTES, PIETER M., THIEDE, JÖRN
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1999
• Subjects: Arctic; Laptev Sea; Anabar; khatanga; laptev; Siberia
• Online Access: http://dx.doi.org/10.1111/j.1502-3885.1999.tb00214.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1502-3885.1999.tb00214.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1502-3885.1999.tb00214.x

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 13 C 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 13 C 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.