STUDY OF THE CONTOURITE DRIFT NORTH OF THE KANE GAP EASTERN EQUATORIAL ATLANTIC
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Abstract (English):
The sediment drift north of the Kane Gap has been investigated by means of the seismoacoustic profiling. The surface area of the drift is about 500 km$^2$ and maximal thickness is 70 m. The contourite drift was formed under the control of the Antarctic Bottom Water AABW flow in the Kane Gap. It is suggested naming this contourite fan as the ``Kane Drift''. Variations in the activity of the AABW current were registered in the sediment core ANS-33056, retrieved near the summit of the drift. For this purpose, the mean size of sortable silt $\overlineSS$, mineral fraction 10--63~$\mu$m was used. It was shown that during the Mid-Pleistocene to Holocene, the speed of the AABW flow north of the Kane Gap was not strictly determined by the alternation of the climatic cycles. A strong relationship between the AABW flow and the short-time climatic fluctuations was found only during the marine isotope stages MIS 4 and 5: intensification of the near-bottom current coincides with the cold intervals. Moreover, during the Terminations II and I MIS~2/1 and MIS~6/5, respectively, the intensity of the current also increased. Maximal near-bottom current activity was registered at the end of the MIS~2.

Keywords:
Seismoacoustic profiling, Antarctic Bottom Water, Kane Drift, paleoceanography
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References

1. Barash, M. S. Quaternary paleoceanography of the Atlantic Ocean - Moscow: Nauka., 1988. - 272 pp.

2. Becker, J. J., et al. Global bathymetry and elevation data at 30 arc seconds resolution: SRTM30_PLUS, // Marine Geodesy, 2009. - v. 32 - no. 4 - p. 355.

3. Diester-Haass, L. Influence of carbonate dissolution, climate, sea-level changes and volcanism on Neogene sediments off Northwest Africa Leg 41, // Init. Repts. DSDP, 1978. - v. 41 - p. 1033.

4. Dittert, N., Henrich, R. Carbonate dissolution in the South Atlantic Ocean: evidence from ultrastructure breakdown in Globigerina bulloides, // Deep Sea Research Part I: Oceanographic Research Papers, 2000. - v. 47 - no. 4 - p. 603.

5. Egloff, J. Morphology of ocean basin seaward of northwest Africa: Canary Islands to Monrovia, Liberia, // AAPG Bulletin, 1972. - v. 56 - no. 4 - p. 694.

6. Emelyanov, E. M., et al. Geology of the Sierra Leone Rise, // Geologische Rundschau, 1990. - v. 79 - no. 3 - p. 823.

7. Faug#xE8;res, J. C., et al. The Vema contourite fan in the South Brazilian basin, // Geological Society, London, Memoirs, 2002. - v. 22 - no. 1 - p. 209.

8. Helmke, J. P., Bauch, H. A. Glacial-interglacial relationship between carbonate components and sediment reflectance in the North Atlantic, // Geo-Marine Letters, 2001. - v. 21 - no. 1 - p. 16.

9. Hobart, M. A., Bunce, E. T., Sclater, J. G. Bottom water flow through the Kane Gap, Sierra Leone Rise, Atlantic Ocean, // Journal of Geophysical Research, 1975. - v. 80 - no. 1 - p. 5083.

10. IOC, IHO, BODC, Centenary Edition of the GEBCO Digital Atlas, published on CD-ROM on behalf of the Intergovernmental Oceanographic Commission and the International Hydrographic Organization as part of the General Bathymetric Chart of the Oceans - Liverpool, UK: British Oceanographic Data Centre., 2003.

11. Johnson, D. A., Rasmussen, K. A. Late Cenozoic turbidite and contourite deposition in the southern Brazil Basin, // Marine Geology, 1984. - v. 58 - no. 1#x2013;2 - p. 225.

12. Jones, E. J. W., Okada, H. Abyssal circulation change in the equatorial Atlantic: Evidence from Cenozoic sedimentary drifts off West Africa, // Marine Geology, 2006. - v. 232 - no. 1#x2013;2 - p. 49.

13. Ledbetter, M. T. Fluctuations of Antarctic Bottom Water velocity in the Vema Channel during the last 160,000 years, // Marine Geology, 1979. - v. 33 - no. 1#x2013;2 - p. 71.

14. Levchenko, O. V., Murdmaa, I. O. Strategy of the lithological and seismoacoustic research of the deep-water deposits along transatlantic geotraverses during cruise 32 of the R/V Akademik Ioffe in the autumn of 2010 Kaliningrad to Ushuaia, // Oceanology, 2013. - v. 53 - no. 1 - p. 124.

15. Lisiecki, L. E., Raymo, M. E. A Pliocene#x2013;Pleistocene stack of 57 globally distributed benthic $\delta$18O records, // Paleoceanography, 2005. - v. 20 - no. 1 - p. PA1003 1.

16. Lund, D. C., Adkins, J. F., Ferrari, Abyssal Atlantic circulation during the Last Glacial Maximum: Constraining the ratio between transport and vertical mixing, // Paleoceanography, 2011. - v. 26 - no. 1 - p. PA1213 1.

17. Mass#xE9;, L., et al. A 600,000-year record of Antarctic Bottom Water activity inferred from sediment textures and structures in a sediment core from the Southern Brazil Basin, // Paleoceanography, 1994. - v. 9 - no. 6 - p. 1017.

18. McCave, I. N., Hall, I. R. Size sorting in marine muds: Processes, pitfalls, and prospects for paleoflow-speed proxies, // Geochemistry, Geophysics, Geosystems, 2006. - v. 7 - no. 10 - p. Q10NN05 1.

19. McCave, I. N., Manighetti, B., Robinson, S. G. Sortable silt and fine sediment size/composition slicing: parameters for palaeocurrent speed and palaeoceanography, // Paleoceanography, 1995. - v. 10 - no. 3 - p. 593.

20. McCave, I. N., Thornalley, D. J. R., Hall, I. R. Relation of sortable silt grain-size to deep-sea current speeds: Calibration of the ``Mud Current Meter'', // Deep Sea Research Part I: Oceanographic Research Papers, 2017. - v. 127 - p. 1.

21. Morozov, E. G., Tarakanov, R. A., Demidov, A. N. Transport of bottom waters in the Kane Gap, // Doklady Earth Sciences, 2010. - v. 433 - no. 2 - p. 1062.

22. Morozov, E. G., Tarakanov, R. Y., van Haren, H. Transport of Antarctic bottom water through the Kane Gap, tropical NE Atlantic Ocean, // Ocean Science, 2013. - v. 9 - p. 825.

23. Myhre, A. M., et al. Explanatory notes, Proceedings of the Ocean Drilling Program, // Initial Reports, 1995. - v. 15 - p. 27.

24. Rebesco, M., et al. Contourites and associated sediments controlled by deep-water circulation processes: state-of-the-art and future considerations, // Marine Geology, 2014. - v. 352 - p. 111.

25. Seibold, E. Sediments in upwelling areas, particularly off Northwest Africa, // Rapp. int. Cons. Explor. Sea, 1982. - v. 180 - p. 315.

26. Sivkov, V. V., et al. Complex studies during the 33rd cruise of the R/V Akademik Nikolaj Strakhov, // Oceanology, 2019. - v. 59 - no. 2 - p. 279.

27. Smith, W. H., Sandwell, D. T. Global sea floor topography from satellite altimetry and ship depth soundings, // Science, 1997. - v. 277 - no. 5334 - p. 1956.

28. Wentworth, C. K. A scale of grade and class terms for clastic sediments, // The Journal of Geology, 1922. - v. 30 - no. 5 - p. 77.

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