N.A. Krivolutskaya1, V.N. Mikhailov2, S.G. Snisar2, B.I. Gongalsky3

1Vernadsky Institute of Geochemistry RAS, Moscow; e-mail: nakriv@mail.ru
2LLC «Norilskgeology», Norilsk
3Institute of Ore deposits RAS, Moscow

The article provides the description of the Mikchangdinsky basic-ultrabasic massif of the trap formation located in the Eastern part of the Norilsk region. This is the first report concerning the Mikchangdinsky intrusion ever published. Its specific features are sulfide mineralization in the endocontact zone and contrast zoned rock-forming minerals. Olivine is of great interest due to its grains graduated in forsterite content 20 mol. % from the core to the rime. This is the pioneer work describing this type of olivines. The authors described the internal structure of the massif, composition variations of rock-forming minerals, petrological and geochemical rock features. The paper concludes that primary Michangdinsky magma was similar to magmas of the Talnakh and Norilsk 1 intrusions with unique Pt-Cu-Ni ores. It is suggested that zoned olivine formation was caused by crystallization of massif in specific geological setting within the North framework of the Khantaisky-Rybninsky swell.

Keywords: Norilsk region, Siberian trap province, zoned olivine.