NEW PALYNOLOGICAL DATA FROM UPPER JURASSIC DEPOSITS OF THE WESTERN CAUCASUS

Abstract

Palynological information is important in the studies of the Upper Jurassic and Lower Cretaceous deposits of the Western Caucasus, but it is still incomplete. New investigations undertaken in the Apsheronsk District of the Krasnodar Region has permitted to reveal better the composition of the peculiar deposits attributed to the Fuabginskaya Formation and to characterize their palynomorph assemblage for the first time. Methodologically, the present work is based on the detailed lithological analysis and the palynological examination of the specially prepared material with the use of microscope approaches. It is established that the studied deposits are represented chiefly by shaly siltstones with lenses of sandstones. The palynomorph assemblage is dominated by gymnosperm pollen (64,2%) and spores of terrestrial plants (11,5%), and there is also microphytoplankton (24,3%), including doniflagellate cysts (up to 20%). The palynological data implies Tithonian (Late Jurassic) age of the siltstones, which are, thus, much older than thought previously. In such a case, the deposits can be attributed to the Podnavislo Formation, whereas the need in the separate Fuabginskaya Formation is questionable. The peculiarities of the rock composition and the palynomorph assemblage allow hypothesizing accumulation of the deposits in a relatively deep-marine basin, but closely to the seashore.