╬. ╬gienko1, Assistant, E-mail: ogienko@univ.kiev.ua


DIATOM ASSEMBLAGES IN THE UPPER LAYER OF BOTTOM DEPOSITS:

DISTRIBUTION OVER MORPHOSTRUCTURAL SHELF ZONES OF THE NORTH-WESTERN ANTARCTIC PENINSULA


1Institute of Geology, Taras Shevchenko National University of Kyiv, 90 Vasylkivska Str., Kyiv, 03022 Ukraine


This paper presents the results of research into marine diatom assemblages in surface shelf deposits of the North-Western Antarctic Peninsula area. Five clusters of diatom assemblages have been identified, according to their taxonomic composition, ecological structure, and distribution in different morphostructural shelf zones. We have considered the factors that affect the assemblage composition and distribution.

In the study area, the dominant diatom species are the antarctic marine planktonic and cryophilic ones, their number increasing considerably in the inner shelf zone due to a natural barrier of big islands. The share of oceanic subantarctic species grows toward the open ocean (in the external shelf). The number of semibenthic and benthic diatoms is substantially larger in the shallow near island waters.

The originality of the investigation is in identifying regular patterns in the diatom taxonomy and ecology depending on their distribution in the surface deposits associated with different morphostructural shelf zones of the North-Western Antarctic Peninsula. The new data on the diatoms may be of use in backstripping analysis of the Antarctic area.

Keywords: diatoms, marine bottom deposits, morphostructural shelf zones, Antarctic Peninsula.


References:

1. Jouse A.P., (1953). To a method of technic processing of rocks for a diatom analysis. Diatom review. Ed. A.I. Proshkina-Lavrenko, V.S. Sheshukova. Leningrad, Publishing house of Leningrad university, 206-220. (In Russian).

2. Greku T.R (2005). Role of ice morphogenesis and tectonics in shaping of Western shelf of the Antarctic Peninsula. Author. Thesis. Candidate. Geol. Sciences: 04.00.10. NAS of Ukraine, Institute of Geological Sciences, Kyiv, p. 24.

3. Lomakin P.D., Sarkisov A.A., Usenko V.P., (2005). Flow characteristics, ice conditions, and inter-island areas rel║fa bottom Argentine Islands archipelago (location station "Academician Vernadsky"). Ekolog│chna bezpeka priberezhno┐ that shelfovo┐ areas that complex vikoristannya resurs│v shelf, National Academy of Sciences of Ukraine, MG▓, ▓GN, PF ▓nBPM, Sevastopol, 12, 307-313. (In Russian).

4. Usachyov P. I., (1949). Microflora of polar ices. Works of institute oceanology of Academy sciences USSR, 3, 216-259 (In Russian).

5. Armand L., Crosta X., Romero O., Pichon J.-J., (2005). The biogeography of major diatom taxa in Southern Ocean sediments: 1. Sea ice related species. Palaeogeography, Palaeoclimatology, Palaeoecology, 223, 93–126.

6. Buffen A., Leventer A., Rubin A., Hutchins T., (2007). Diatom assemblages in surface sediments of the northwestern Weddell Sea, Antarctic Peninsula. Marine Micropaleontology, 62, 7–30.

7. Crosta X., Romero O., Armand L., Pichon J.-J., (2005). The biogeography of major diatom taxa in Southern Ocean sediments: 2. Open ocean related species. Palaeogeography, Palaeoclimatology, Palaeoecology, 223, 66–92.

8. Kaczmarska I., Barbrick N.E., Ehrman J.M., Cant G.P., (1993). Eucampia Index as an indicator of the Late Pleistocene oscillations of the winter sea-ice extent at the ODP Leg 119 Site 745B at the Kerguelen Plateau. Hydrobiologia, 269/270, pp.103-112.

9. Pike J. et al., (2009). Observations on the relationship between the Antarctic coastal diatoms Thalassiosira antarctica Comber and Porosira glacialis (Grunow) Jorgensen and sea ice concentrations during the Late Quaternary. Marine Micropaleontology, 73, 14–25.

10. Romero O.E., Armand L.K., Crosta X., Pichon J.-J., (2005). The biogeography of major diatom taxa in Southern Ocean surface sediments: 3. Tropical/Subtropical species. Palaeogeography, Palaeoclimatology, Palaeoecology, 223, 49-65.

11. Taylor F., Whitehead J., Domack E., (2001). Holocene paleoclimate change in the Antarctic Peninsula: evidence from the diatom, sedimentary and geochemical record. Marine Micropaleontology, 41, 25-43.