Age of the Obnazhennaya kimberlite pipe (northeastern Siberian platform)

Abstract

In this article, we discuss the age range for the formation of the Obnazhennaya kimberlite pipe (Kuoyka field, north-eatern Siberian platform) considering the recent unique discovery of a representative of the Toarcian-Early Aalenian (end of the Early–beginning of the Middle Jurassic) belemnites along with the revision of previously known belemnites of the Upper Jurassic–Lower Cretaceous age. We investigated the specifics and general genesis of the facies in the complex vertical structure of the sections. In addition, we assessed the role of the ancient Kimmeriyan, Dunlap, and New Cimmerian phases of Cimmerian tectono-magmatic activation in the stabilization of the Kuoika and Khorbusuon kimberlite fields. Moreover, a new model of the eruptive system of Mesozoic kimberlite fields was considered. The existing paleogeographic schemes of the Toarcian-Early Bathonian interval northeast of the Siberian Platform have been corrected. The study location provides important evidence of the disappearance scale of marine ingression traces in the geological record.