Lower and Middle Jurassic Stratigraphic Scheme of the Western Caucasus: Problems of Correlation and Division

Abstract

The western part of the official regional stratigraphic schemes of the Lower and Middle Jurassic of the Caucasus is considered in this paper. The completion of this work allows an assessment to be made of the degree of validity of the various stratigraphic units according to the requirements of the Stratigraphic Code of Russia and of their association in groups. In the published descriptions of some formations, there is an insufficient amount of information to establish new local stratigraphic units according to the requirements of the Stratigraphic Code of Russia. Therefore, there is no particular justification for the legitimacy of these stratigraphic units. This review of the stratigraphic division of the Lower and Middle Jurassic of some zones of the Western Caucasus and the validity of the establishment of formations and groups illuminates the different degree of development of the stratigraphic schemes for all zones of the region considered. New groups are presented herein and the stratigraphic intervals of several known groups are changed. Some proposals for improving the stratigraphic scheme for the Caucasus are presented and discussed in the paper.