Structure and development of the El’gigitgin depression

Abstract

The El'gigitgin depression consists of two structures of different age: a large Miocene-Early Pliocene structure (El'gigitgin-1) and inner one of Late-Pliocene-Pleistocene age (El'gigitgin-2) - the El'gigitgin lake. New data on lake's bottom morphology were obtained by echo sounding in 1994. The age of structures was determined on the base of palynologic data. The analysis of impactite distribution in the depression and in the Pliocene sediments of river Enmivaam was used as well. The comparison of the depression with the ring structures at the shields and ancient platforms was made. The development of El'gigitgin depression was attended by endogenous impactogenesys.