ИСТИНА

The results of a comprehensive study of the Turonian-Coniacian deposits of the Abinsk region of the Northwestern Caucasus, represented by a rhythmically built carbonate-terrigenous stratum, are presented. The use of petrographic, lithofacies, X-ray diffraction, micropaleontological and isotopic analyzes made it possible to reveal important changes in abiotic and biotic events during this interval. Features of carbonate sedimentation, changes in the composition of foraminiferal complexes made it possible to establish fluctuations in the relative sea level, and isotope studies helped to identify climatic fluctuations. During the periods of accumulation of carbonate and clayey material, the territory was a relatively deep open sea basin with normal sea salinity. During the Late Turonian-Early Coniacian interval, two cooling pulses were recorded against the background of high temperatures. The section is proposed as a hypostratotype of the lower boundary of the Coniacian.