Principal contradictions in the way of West Siberian berrias-aptian deposit’s regional stratigraphic schemes developing

Abstract

The regional stratigraphic schemes of Jurassic and Cretaceous deposits in Western Siberia, approved over the last fifty years, reflect a conflict between the current clinoform concept and an outdated plane-parallel model. The “survivability” of the outdated model in the main stratigraphic documentation of the sedimentation basin is explained by the rejection of scientific comprehensive interpretation principle in former discussions. In these discussions, the biostratigraphic age evaluations had grand favor primacy in compare with any geophysical and geological information in conflict situation. 

Materials and methods. This study analyzes and compares the data from the clinoform lithostratigraphic model with the available biostratigraphic dates for the current stage of sedimentary basin research. 

Conclusions. The lithologostratigraphic model has greater proven reliability and accuracy than disparate biostratigraphic dates. On the one hand, there are hundreds of thousands of reservoir intersections in wells and millions of points of seismic interpretation in the inter–well space. On the other hand, there are less than five hundred valid definitions of index fossils (ammonites) for the entire productive sequencts.

Suggestion. Notes the need for urgent resumption of the work of the Regional Interagency Stratigraphic Meeting. It should prepare a balanced version of the stratigraphic schemes for the Upper Jurassic and Berriasian-Aptian deposits. We propose a methodology for developing complex, verified collective stratigraphic solutions through the efforts of the Regional Meeting.