Mutually according concept for biostratigraphic data and clinoform model of western siberian tithonian-barremian deposits

There is a unique situation for past decades with Western Siberia Tithonian-Barremian deposit’s regional schemes: the clinoform model of their structure is generally accepted in regional oil exploring organizations, and at the same time, there exists inconsistency between this model and scientific interpretations of current biofacilitie’s complex. Main goal of this work is initialization of public scientific discussion. Superstitious biots. The Bazhenov bituminous formation is an integral clinoform model part — central basin deep fine-grained sediments (fondothem by Rich). It is proposed to take clinoform strata structure as conceptual basement of paleobiotic analysis to overcome existing discrepancies. West Siberian paleobasin lateral filling led to a constant replacement of its paleogeographic and environmental condition zones. Superstite (endemic) biotic complexes could be controled by ecological niches, sliding in age along with lithological boundaries. The ecological niche for ammonoids could be poorly ventilated normal salinity waters underlying the brackish waters of the halocline protruding beyond the shelf edge. Absolute age criterion . There is a regionally consistent marker — a tufite layer — at the Upper Bazhenov subformation bottom part. Microanalysis of its zircon grains estimated U‒Pb age as 140.2–141.11 million years, which is in good agreement with the clinoform model. The biofacilities revision might be operated looking for posible coexisting endemic superstite and panboreal (cosmopolitan) ammonites and other stratifying organisms. The currently accumulated complex of biostratigraphic data does not directly contradict the clinoform model. A working regional scheme of West Siberian Tithonian-Barremian deposits with a developed agreed upon correlation part and with a general biostratigraphic part’s intermediate version might be submitted for consideration of Russin Interdepartmental Stratigraphic Committee.