New data concerning the age and composition of intrusion complexes of the northern part of Balygychan-Sugoi rift depression (North-Eastern Russia)

The Balagychan-Sugoi (Omsukchan) riftogeneous depression is described by different authors both as a part of Okhotsk-Chukotka volcanic belt (OCVB) and separate structure. unique Dukat gold silver deposit lot others ore deposits including rare-metal, such Arylah, Lunnoe, Askold, Mechta, Tidid, Krasin, are associated with this All mentioned objects located in the south from point view connected OCVB Evolution Balygychan-Sugoi closely related to stages magmatic evolution region. In article, these characterized based on data form intrusion bodies northern (Naygain depression). This most outlying less investigated. For first time, U-Pb zircon baddeleyite dating description petrographic geochemical composition have been carried out for Mandychan gabbro-diorite Nayahan gabbro leucogranite complexes Omsukchan complex. Late Jurassic – Early Cretaceous intrusions Mandychansk complex dated 143-139 Ma mark beginning rift formation. Intrusion granitoids 84-85 81-82 correspondently new stage activity, synchronous compositions indicate their belonging I-type granites, which typical extension environments, whereas leucogranites some features corresponding A-type granites.