Paragenetic diversity of the composition garnets from kimberlites Nakyn field (Yakutia)

Abstract

Studied the composition of garnets from three kimberlite bodies of Nakyn field (Nyurbinskaya and Botuobinskaya pipes, Markhinskaya dyke). Paragenetic specialization of garnets was determined on the basis of their chemical composition with use of the original MineralogicalAnalyse program. This program was specially created for paragenetic classification of kimberlite minerals and is currently capable of recognizing 41 paragenesis by the composition of garnets. The set of paragenetic groups determined by the program most fully characterizes paragenetic diversity of the composition garnets from kimberlites and associated placers to date. A significant difference was established between the kimberlite bodies of Nakyn field, both in the set of different garnet paragenesis and in their percentage. A distinctive feature of garnets this field is the increased content of eclogite paragenesis among them. Xenoliths of metamorphic basement rocks did not significantly affect the paragenetic association of garnets from studied kimberlite bodies. Using of the Mineralogical Analyse program allows one to judge both paragenetic affiliation of garnets and the deep sources of diamonds of specific kimberlite bodies.