Exotic Olivine-Mica Rocks from the Udachnaya-East Pipe (Yakutia): Features of the Chemical Composition and Origin

Abstract

The chemical composition of rock-forming minerals from unusual olivine-mica rocks from the Udachnaya-East kimberlite pipe (Yakutia) was studied. It is shown that all these rocks were formed as a result of the influence of deep metasomatic fluids. Two ilmenite-bearing rocks show the similarity to polymict breccia genetically representing analogs of protokimberlite melts, which did not reach the Earth’s surface. Two other rocks (one with K-bearing amphibole, another with clinopyroxene) are most likely rocks from the zones of high permeability, which were formed upon consolidation of the Siberian Craton and were subjected to the influence of aggressive fluids from the early portions of the protokimberlite melt.