FORMATION OF LOWER AND MIDDLE JURASSIC COALIFEROUS SEQUENCES IN THE NORTHERN CAUCASUS

Abstract

Pliensbachian coaliferous sequences were formed along the southern margin of the Stavropol Uplift in various paleogeographic environments. Therefore, peat bogs are developed in various landscape zones. In the southern Kuban coaliferous district, which adjoins the tectonically active central Caucasus, coaliferous sediments were formed in river valleys, whereas peat bogs were developed in swamped valleys. In the northern Kuban and Baksan coaliferous districts situated away from this region, coaliferous sediments were formed under conditions of alluvial–deltaic and alluvial–lacustrine plains. Peat bogs were localized in the swamped alluvial–deltaic and alluvial–lacustrine plains. In the Laba–Urup and southeastern Baksan coaliferous districts situated far away from the tectonically active central Caucasus and dominated by partly isolated bays and lagoons (or coastal plains), peat bogs were formed in the swamped (partly isolated) bays and lagoons (or coastal plains). Similar environments of sedimentation and peat deposition were typical of the Daghestan coaliferous district in the early Aalenian and Bathonian of Middle Jurassic.