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Against the background of the general transgressive sequence of the Upper Cretaceous deposits of the West Siberian Plate, local intervals of the regressive structure are distinguished, represented by clastic rocks (siltstones, psammites). In them there are sometimes signs of erosion weathering (clarification along fracture zones, traces of roots, large vegetable detritus). Over the past decades, in the process of exploration and exploitation of oil and gas fields in Western Siberia, significant volumes of factual information have been accumulated, many times exceeding the level of study of the mid-1970 years. On the basis of a comprehensive analysis of geological and geophysical materials in Western Siberia, the environment and conditions of sedimentation are detailed, the author's conceptual model of the structure of the Western Siberian Upper Cretaceous is proposed. In the section of the Upper Cretaceous, sediments of various genesis are well traced. Transgressive deposits in general are composed mainly of chemogenic-biogenic siliceous-clay sediments of the autochthonous type. Episodes of local regressions are reflected by wedge-shaped packs (for example, late-Turonian Gas-Sale memberk) of clay siltstones and psammites (terrigenous, allochthonous type), rather limited in the east and northeast of Western Siberia. Four sediment stratums have been divided on Western Siberia Turonian – Maastrichtian. There are Kuznetsovo (Turonian – Lower Coniacian), Nizhneberezovo (Middle Coniacian – Santonian), Werkhneberezovo (Campanian) and Gankino (Upper Campanian – Maastrichtian) complexes. Schemes of seismic complexes and members are created on seismic data and geophysical wells investigation, with laboratory core analyses results. The composition and structure of stratones is characterized by the results of laboratory core research, with the use of published data.Brief characteristic of Coniacian – Santonian siliceous clayey deposits has been done. References 1. Lisitsyn A.P., Lavinnaya sedimentatsiya i pereryvy v osadkonakoplenii v moryakh i okeanakh (Avalanche sedimentation and interruptions in sedimentation in the seas and oceans), Moscow: Nauka Publ., 1988, 309 p. 2. Emel'yanov E.M., Bar'ernye zony v okeane: Osadko- i rudoobrazovanie, geoekologiya (Barrier zones in the ocean: sedimentogenesis and ore formation, geoecology), Kaliningrad: Yantarnyy skaz Publ., 1998, 416 p.
3. German A.B., Al'bskaya-paleotsenovaya flora Severnoy Patsifiki (Albian-Paleocene flora of the Northern Pacific), Moscow: GEOS Publ., 2011, 280 p. |
