STRUCTURAL REFLECTION OF THE MIRNYY KIMBERLITE FIELD IN THE SEDIMENTARY COVER

Abstract

Much attention has recently been paid to the structure of kimberlite fields at different crustal levels. Here we try, from the results of mass logging of wells drilled in the Malaya Botuobuya district, to clarify whether the Mirnyy kimberlite field is structurally reflected in the upper part of the kimberlite-bearing sedimentary craton cover, i.e., at the Vendian-Lower Paleozoic level. Our data indicate that the Mirnyy kimberlite field is an area of the crust where the upper part of the sedimentary cover has an anomalously complex structure. This area seems to be a permeable crustal zone, whose contour can be considered the structural boundary of the Mirnyy kimberlite field. The kimberlite bodies themselves are controlled by submeridional graben-shaped downwarps, 2 to 4 km wide and complicated by narrow low-amplitude troughs, along which faults of the Vilyuy-Markha zone are traceable.