OTOCERAS ZONE - A UNIQUE GEOLOGICAL OBJECT OF THE SOUTH VERKHOYANIE

The Otoceras zone can be considered a unique geological object in the Southern Verkhoyanie. It is of great interest not only among paleontological researchers, but also among geology students, since the location of the “Tomponsky educational geological survey site of NEFU” is located at 638 km of the Yakutsk-Magadan highway in the valley of the Eastern Khandyga River, where Permian-Triassic deposits containing ammonoids of the genus Otoceras are exposed. The Otoceras beds are an important stratum for identifying, tracing and correlating the Permian-Triassic boundary deposits in the Notal and Boreal regions. The structure of the Otoceras beds on the right bank of the Setorym River involves two sequences of silty mudstones with a thickness of 10 and 18 m. The network consists of two sequences of silty mudstones with a thickness of 10 and 18 m. In the lower sequence (unit 3), two successive ammonoid complexes are established, allowing it to be divided into the Otoceras concavum and Otoceras boreale zones. The upper sequence (unit 5) contains rare ammonoids of the advanced species Otoceras sp. 1, allowing it to be attributed to the subzone of the same name, located in the upper part of the Otoceras boreale zone.