PETROLOGICAL FEATURES OF OLIVINE-PHLOGOPITE LAMPROITES OF THE SAYAN REGION: EVIDENCE FROM SR-ND ISOTOPE AND ICP-MS TRACE-ELEMENT DATA

Abstract

The only occurrence of Middle Riphean diamondiferous magmatism in the Siberian Craton is the diamondiferous lamproites of the Sayan region, which are located in the Ingashi River basin, a right tributary of the Oka River, in its middle reaches. The lamproites form a series of vein bodies and together with local halos of indicator minerals compose the Ingashi lamproite field, ~30 km long and 5–8 km wide.