Conjugation of chemical compositions of rocks and accessory minerals in kimberlites

Vasilenko V. B., Zinchuk N. N., Kuznetsova L. G.

Zapiski RMO (Proceedings of the Russian Mineralogical Society). 2019. V. 148. N 3. P. 14-29

https://doi.org/10.30695/zrmo/2019.1483.01

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Language: Russian

Abstract

A general conclusion regarding the comagmaticity of pyrope, diamond and rock-forming minerals of kimberlites is made. The data on diamond deposits in Yakutia, including kimberlite pipes: Botuobinskaya, Nyurbinskaya, Internationalnaya, Mir, Aikhal, Yubileinaya, Sytykanskaya, Udachnaya-Western, Udachnaya-Eastern, and Zapolyarnaya, have been used in the study. The total database of bulk rock compositions includes more than 7000 analyses, of which 1976 are accompanied by data on diamond contents in the kimberlites, and 1529 chemical rock compositions are accompanied by neutron activation analyses of chromium contents in the rocks. The pyrope compositions database contains 1491 microprobe analyses. The compositions of picroilmenites are characterized by 986 microprobe analyses. Literature data on the discrepancy between the ages of kimberlites and inclusions in diamonds are considered. To substantiate the validity of the obtained conclusions, variation coefficients of contents of rock-forming oxides in 25 volcano-plutonic formations and kimberlite rocks are compared.

Key words: diamond, pyrope garnet, picroilmenite, kimberlite, diamond-bearing, petrochemistry, comagmaticity