Characteristics of the Deep Structure of the Kimberlite-Controlling Faults of the Arkhangelsk Diamondiferous Province According to the Microseismic Sounding Method. Review

Prospecting for kimberlite pipes can be challenging due to their small size in plan. One potential solution to this problem is to search for kimberlite-controlling faults. In addition, information on the depth structure of kimberlite-controlling faults is important for studying pipe formation patterns. However, this approach is rarely used in practice due to the complex structure of the host environment. This issue is particularly pressing in areas where there is a large layer of rocks overlying the pipes, such as the Arkhangelsk diamondiferous province. The paper presents a review of the host environment structure of pipes in the Arkhangelsk diamondiferous province using the microseismic sounding method. The method was selected for its high horizontal resolving power, which enabled us to obtain more detailed information. The study reveals that the controlling structures consist of a sequence of vertical elementary faults that traverse the entire thickness of the Vendian sedimentary cover and extend into the crystalline basement. Additionally, the controlling structures do not penetrate above the Ust-Pinezhskaya formation of the Vendian sediments when at a distance from the pipes. Shear wave velocities within these faults are reduced by more than two times compared to the undisturbed medium. The pipes are interconnected with one of the elementary faults. Therefore, the method of microseismic sounding can confidently identify kimberlite-controlling structures in a complex host medium. Further application of these results could enhance the efficiency of both the search for new deposits and the study of the patterns of formation of pipes.