1 - Kopenok, Olga B., 1 - Marchenko, Anna S., 1 - Ruban, Dmitry A., 2 - Nielsen, Jan K.

1 - Division of Mineralogy and Petrography, Department of Earth Sciences, Southern Federal University, Zorge st., 40, Rostov-na-Donu, 344090, Russia, E-mail: ruban-d@mail.ru
2 - StatoilHydro ASA, TNE SST Reservoir Technology, IOR Studies, P.O. Box 273, NO-7501 Stjoerdal, Norway

Trace fossils are sensitive indicators of the depositional environment, and their new findings in the Upper Paleocene deposits of the Abazinskaya Formation in the Southern Ciscaucasus allow some new interpretations. Urohelminthoidea isp., Chondrites intricatus, and Ophiomorpha isp. have been identified from the diagenetically-altered diatomites in the Yutsa section. The presence of Urohelminthoidea favors recognition of the Nereites ichnofacies in the Abazinskaya Formation. It indicates to deep-water environment of the basin slope or floor, where bacterial gardens were grown up extensively. Such depositional environment coincided with subsidence of the Greater Caucasus Basin during Late Paleocene.

Keywords: trace fossils, agrichnia, fodinichnia, ichnofacies, depositional environ-ment, basin depth, diatomites, Paleocene, Ciscaucasus