## 1 Introduction  
The Arkhangelsk Diamondiferous Province (ADP) in the Arctic zone of Russia is the sole diamondiferous region in Europe with commercial diamond reserves [1, 2, 3]. Moreover, ADP is a relatively young formation with underinvestigated circumstances of its genesis [4]. These facts highlight the necessity for further investigation of the deep structure of the region. At present, in excess of 50 alkaline-ultrabasic rock blast pipes have been identified across the province, with a concentration within a few fields. Most of the pipes were discovered in the 1980s. The last significant discovery was the V. Griba deposit in 1996. At the same time, the geological characteristics of the region indicate the potential for discovering new diamond deposits [5]. Given that the majority of ADP falls within the category of closed prospecting areas [6], magnetic prospecting has historically constituted the primary and dominant geophysical method. Nevertheless, the reservoir of promising high-amplitudelocal magnetic anomalies for confirmation by drilling is now depleted [7]. The work is carried out with the existing prospective areas at the level of accuracy of an aeromagnetic survey [3]. The application of schlicho-mineralogical methods for prospecting also yielded unsatisfactory results, as kimberlites in the Arkansaski diamondiferous province exhibit a relatively low concentration of indicator minerals, particularly pyrope [8; 9; 10]. In this regard, there is an urgent need to introduce new geophysical research methods, integrated interpretation of geological and geophysical information, modernization and optimization of existing prospecting techniques, and an increase in the volume of geological exploration work [5; 6]. A number of researchers have identified non-traditional methods of searching for hidden ore-bearing and ore-controlling structures as the most promising avenues for exploration [3; 6; 11; 12; 13]. The identification and study of such structures by traditional geophysical methods often yield inconclusive results due to the closed nature of the territory and the weak manifestation of ore-controlling faults in the physical fields [14]. One promising avenue for locating kimberlite deposits is the method of microseismic sounding (MSM) in conjunction with radiogeochemical techniques. One such technique is the study of the 222 Rn field distribution over explosion pipes [15]. The principal benefit of MSM is its high horizontal resolution. This characteristic has been demonstrated in a number of field experiments and through mathematical modeling [16; 17]. Therefore, MSM is able to accurately delineate the depth structure of a range of subvertical features, including faults, kimberlite pipes, and volcanoes [15; 17; 18; 19; 20]. Within the ADP, the method was first tested on the Lomonosov pipe [21]. The pipe was identified as a cone-shaped body facing downwards with a contrast lower than the contrast of the faults. Further studies confirmed the results obtained. The structure of the pipes to depths of 1-2 km was determined based on the data obtained. At the same time, it was shown that pipes in different kimberlite fields can manifest themselves with different characteristics: both high-velocity and low-velocity [22; 23]. In terms of radiogeochemistry, kimberlite pipes create zones of radioactive elements and radon on the Earth's surface [24]. Given the significant degree of overlap between the layers in question, the only viable method for registering these anomalies is through ground survey, utilizing equipment with an exceptionally high level of sensitivity. Concurrently, a gamma-spectrometric survey enables the delineation of these zones with greater expediency. The advancement of fracturing within the peritubular space and along the controlling faults results in an augmented radon flux.