Affiliation:
1. Shirshov Institute of Oceanology, Russian Academy of Sciences
Abstract
Lithological and micropaleontological (planktonic and benthic foraminifers, diatoms) studies in four sediment cores revealed major patterns of lithostratigraphy and biostratigraphy of contourites and gravitites in the uppermost sediment layer within the depth range 3500–4300 m of the northern sector of the Patagonian continental slope contourite system. It is ascertained that in conditions of low terrigenous material supply from the land and high, although variable bottom contour current velocities of waters of Antarctic origin, hemipelagic calcareous nanno-foraminiferal ooze deposited in the Holocene over middleupper Pleistocene contourites in the southern part of the study area (cores AI–2609, AI–2610). The Holocene calcareous surface layer is absent in the northern part of the study area (cores AI–2611, AI–2612). Middle-Upper contourites and gravitites are unevenly enriched in diatoms and radiolarians here, up to formation of slightly siliceous-terrigenous diatomaceous mud. Reworked Neogene foraminifers and diatoms evidence for erosion of Neogene deposits bottom currents and gravity flows.
Funder
Russian Science Foundation
Publisher
P.P. Shirshov Institute of Oceanology, RAS
Reference30 articles.
1. Ivanova E.V., Murdmaa I.O., Borisov D.G., Isachenko S.M., Seitkalieva E.A., Bashirova L.D., Blinova E. V., Ul’yanova M.O., Lapidus L. V., and Fidaev D.T. Investigation of Contourite Systems in the South Atlantic during Cruise 46 of the R/V Akademik Ioffe. Oceanology, 2016, Vol. 56, No. 5, pp. 322–324, https://doi.org/10.1134/S0001437016040044.
2. Barron J.A. Miocene to Holocene planktic diatoms. In: Bolli H.M. et al. (Eds.). Plankton Stratigraphy, Cambridge: Cambridge University Press, 1985, pp. 763–809.
3. Barron J.A, Bukry D., Dea W., Addison J.A., and Finne B. Paleoceanography of the Gulf of Alaska during the past 15,000 years: Results from diatoms, silicoflagellates, and geochemistry. Marine Micropaleontology, 2009, Vol. 72, pp. 176–195, doi: 10.1016/j. marmicro.2009.04.006.
4. Bé A.W.H. and Tolderlund D.S. Distribution and ecology of living planktonic foraminifera in surface waters of the Atlantic and Indian oceans. In: The micropaleontology of oceans, London: Cambridge Univ. Press, 1971.
5. Cody R.D., Levy R.H., Harwood D.M., and Sadler P.M. Thinking outside the zone: high-resolution quantitative diatom biochronology for the Antarctic Neogene. Palaeogeography, Palaeoclimatology, Palaeoecology, 2008, Vol. 260(1–2), pp. 92–121, doi: 10.1016/j.palaeo.2007.08.020.