New paleomagnetic data on marine sediments from the Central Arctic Ocean
- 1Gramberg All-Russian State Research Institute for Geology and Mineral Resources of the Ocean (VNIIOkeangeologia), Marine Seismic Department, SAINT PETERSBURG, Russian Federation (darielfly@gmail.com)
- 2Saint Peterburg State University
- 3Bremen University
- 4Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research
Accurate dating of marine sediments from the Arctic Ocean remains a subject of great debate over the last decades. Due to the lack of adequate materials for biostratigraphy and stable isotope analyses, paleomagnetic reconstructions came into play here but though yielded ambiguous interpretations. Moreover, sedimentation rates in the Quaternary, determined for isolated morphological features in the Arctic Ocean, are often applied to the entire Arctic Ocean realm resulting in an inappropriate oversimplification of probably diverging regional depositional regimes.
Paleomagnetic studies on four long sediment cores, collected from the Mendeleev Ridge and the Lomonosov Ridge, complemented by the results from one core from the Podvodnikov Basin, have provided an opportunity to compare the sedimentation history of these profound structures in the Arctic Ocean. Cores PS72/396-5 and PS72/410-3 (Mendeleev Ridge), PS87/023-1, PS87/030-1 (Lomonosov Ridge) and PS87/074-3 (Podvodnikov Basin) were retrieved during expeditions of RV Polarstern in 2008, and 2014. Paleomagnetic, rock magnetic and physical properties measurements were carried out at the Center for Geo-Environmental Research and Modeling (GEOMODEL) of the Research Park in St. Petersburg State University, at the University of Bremen, and the Alfred Wegener Institute.
According to the results on the Mendeleev Ridge’s cores, complemented with 230Th excess study on core PS72/396-5, the Brunhes Matuyama boundary (0.78 Ma) is observed at the first meters below the seafloor. That, together with the Matuyama Gauss transition (2.58 Ma) recorded in both cores, implies the mean sedimentation rate in this area to be in the order of mm/kyr.
In contrast to the Mendeleev Ridge, the cores from the Lomonosov Ridge and the Podvodnikov Basin have shown a more complex paleomagnetic record with a relevant shift to negative inclinations significantly deeper downcore. This could signify a relevant difference in the sedimentation regimes between both ridges during the Quaternary.
How to cite: Elkina, D., Frederichs, T., Geibert, W., Matthiessen, J., Niessen, F., Piskarev, A., and Stein, R.: New paleomagnetic data on marine sediments from the Central Arctic Ocean, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21920, https://doi.org/10.5194/egusphere-egu2020-21920, 2020
How to cite: Elkina, D., Frederichs, T., Geibert, W., Matthiessen, J., Niessen, F., Piskarev, A., and Stein, R.: New paleomagnetic data on marine sediments from the Central Arctic Ocean, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-21920, https://doi.org/10.5194/egusphere-egu2020-21920, 2020
