Peculiarities of the Composition of Zoned Picroilmenites from the Massadou Field (Giunea) and Dachnaya Pipe (Yakutia) Kimberlites

摘要

Numerous publications [1, 3, 6, 11, 12, 14] concern picroilmenite, a magnesium variety of ilmenite typical for kimberlite. This mineral attracts interest in light of the kimberlite petrogenesis, as well as because it is the most abundant kimberlite indicator. In some cases the concentration of picroilmenite in kimberlite is tens kg/t [2], and the grain sizes range from 0.0n mm to 15 cm. Picroilmenite is quite abundant in xenoliths of garnet lherzolite including cataclastic ones and wehrlite [3, 5].