NEW DATA ON THE STRATIGRAPHY OF WEST-SIBE RIAN TRIASSIC SEDIMENTS

The West-Siberian Triassic sediments are analyzed with the emphasis gi ven to their composition and stratigraphic subdivision based on large- size remains of fauna, flora and microfossils. The Triassic sediments penetrated by deep wells and containing bivalvia shells, spores and po llen are stratigraphically considered here. A specific palynocomplex i s found in the sediments, allowing recognition of the Olenek Stage, Be cause of the great number of acritarchs (one of the dominant of the st age) the sedimentation is supposed to occur in rather a huge saline-wa ter basin. New data on the stratigraphy of new Triassic sections are i mportant for detecting the geological structure of the West-Siberian p re-Jurassic complexes and for assessment of their oil and gas potentia l.