Organic geochemistry on sediment profiles from the Arctic Ocean

• Main Author: Schubert, Carsten J
• Format: Other/Unknown Material
• Language: English
• Published: PANGAEA 2009
• Subjects: Amundsen Basin; ARK-VIII/3; AWI_Paleo; Gakkel Ridge; Arctic Ocean; Giant box corer; GKG; KAL; Kasten corer; Lomonosov Ridge; Makarov Basin; MUC; MultiCorer; Nansen Basin; Paleoenvironmental Reconstructions from Marine Sediments @ AWI; Polarstern; PS19/152; PS19/153; PS19/154; PS19/157; PS19/159; PS19/165; PS19/166; PS19/171; PS19/172; PS19/173; PS19/175; PS19/176; PS19/178; PS19/182; PS19/183; PS19/185; PS19/186; PS19/190; PS19/194; PS19 ARCTIC91; PS2159-3; PS2160-3; PS2161-1; PS2163-1; PS2165-5; PS2170-4; PS2171-2; PS2171-4; PS2174-2; PS2174-5; PS2175-4; PS2176-2; PS2176-3; amundsen basin; Arctic; Berichte zur Polarforschung; Iceberg*; makarov basin; Polar Research; Polarforschung; Reports on polar research; Sea ice; Spitsbergen
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.729809; https://doi.org/10.1594/PANGAEA.729809

During the ARCTIC '91-Expedition with RV 'Polarstern', several Multicorer and Kastenlot-cores were recovered along a profile crossing the eastern part of the Arctic Ocean. The investigated cores consist mainly of clayey-silty sediments, and some units with a higher sand content. In this thesis, detailed sedimentological and organic-geochemical investigations were performed. In part, the near surface sediments were AMS-14C dated making it possible to Interpret the results of the organic-geochemical investigations in terms of climatic changes (isotopic stage 2 to the Holocene). The more or less absence of foraminifers within the long cores prevented the development of an oxygen isotope stratigraphy. Only the results of core PS2174-5 from the Amundsen-Basin could be discussed in terms of the climatic change that could be dated back to oxygen isotope stage 7. Detailed organic-geochemical investigations in the central Arctic Ocean are rare. Therefore, several different organic-geochemical methods were used to obtain a wide range of data for the Interpretation of the organic matter. The high organic carbon content of the surface sediments is derived from a high input of terrigenous organic matter. The terrigenous organic material is most likely entrained within the sea-ice On the Siberian shelves and released during ice-drift over the Arctic Ocean. Other factors such as iceberg-transport and turbidites are also responsible for the high input of terrigenous organic matter. Due to the more or less closed sea-ice Cover, the Arctic Ocean is known as a low productivity system. A model shows, that only 2 % of the organic matter in central Arctic Ocean sediments is of a marine origin. The influence of the West-Spitsbergen current increases the marine organic matter content to 16 %. Short chain n-alkanes (C17 and C19) can be used as a marker of marine productivity in the Arctic Ocean. Higher contents of short chain n-alkanes exist in surface sediments of the Lomonosov-Ridge and the Makarov-Basin, indicating a higher marine ...