The assessment of the impact of natural and anthropogenic factors on the current stressstrain state of rock massif of burst-hazardous ore deposits in the East of Russia

Abstract

This paper does a case study of endogenous deposits located in the zone of influence of convergent (converging, colliding) boundaries of tectonic plates in the zone of the continent-ocean transition, where there is increased present seismic and geodynamic activity, covers the issues of the ratio of natural and anthropogenic components of the stress-strain state (SSS) in rock massifs. It has been shown that, despite the confinement of the studied deposits to a single rock structure, as well as the proximity of their common neotectonic position, the SSS of the rock massifs containing them varies significantly. Based on a comprehensive analysis of geological and geophysical data with the use of space data about the Earth (GRACE mission data for calculation of stress fields and radar images of the Earth's surface), the kinematics of the process of modern deformation of the upper part of the Earth's crust within the studied area is specified. It is established that the peculiarity of the region is the pronounced contribution of the natural component to the general present SSS of rock massifs of impactthreatening deposits. On a real example, the possibility of a predictive assessment of SSS has been shown, which is important at the stages of designing and conducting underground mining operations in severe mining-geological and burst -hazardous conditions.

Geodynamic risks of developing rockburst-hazardous deposits in the Far Eastern region

“…In addition, it should be borne in mind that according to previously obtained results [10], in historical time intervals (months, years, decades, etc.) within the Amur craton, selective geodynamic activation of faults or their parts was observed, which is associated with the time sequence and direction of a certain seismic process.…”

“…1 -faults bounding the Amur geoblock; 2 -faults bounding the inner blocks of the lithospheric plate: a -Border deep fault dividing the Amur Plate into blocks; I order; b, cother, mainly interblock, neotectonic faults within the Amur Plate; 3earthquakes registered by the stations network of the FRC GS RAS from January 2019 to May 2021 with M ≥ 4; 4 -areas of tectonically neutral stress state; 5 -compression areas; 6 -strike-slip areas; 7 -areas of compression with a strike-slip; 8extension areas; 9 -ore deposits dangerous and prone to rockburst: Z-H -Zun-Kholbinskoye; I -Irokindinskoe; D -Darasun; A -Antey; X -Khinganskoe; Pr -Perevalnoye; V -Vostok-2; Yu -Southern; Z -Forgotten; N -Nikolaevskoe; P -Partisanskoe. The Amur lithospheric plate (or geoblock) is a tectonic element of the Central Asian Orogenic Belt, which is sandwiched between the North Asian and Sino-Korean craton [10]. According to the interpretation of seismic materials, the modern horizontal movement of the Amur Plate occurs under external force from the North Asian Craton (Siberian Platform).…”

“…Based on the results of field measurements at specific deposits, the spread of the expected values of the modern compression of the upper part of the Earth's crust of the Amur Plate can range from 20 to 100 MPa and maybe more. Moreover, the position of the known impact-prone deposits of the Amur Plate, both in relation to its boundaries and in relation to the distinguished neotectonic elements, differs significantly and this circumstance cannot be ignored in their structurally scalable geomechanical assessment [10,11].…”

“…This is expressed by the presence of highly active seismic belts: from the north and northwest -Baikal-Stanovoy, from the east -Sakhalin. The inner region of the Amur Plate is characterized by relatively low seismicity [10].…”

“…Previously performed geodetic studies have established the specifics of fluctuations of different-scale blocks of rocks under the influence of natural and mining-induced seismicity, and the analysis of seismoacoustic data has shown the nature of the development of cracking in certain areas, preceding the destruction of the massif sections in dynamic form [10][11][12]. In the course of the studies carried out on rockburst hazardous deposits, areas with varying degrees of probability of mining-induced earthquakes during seismic activity of the blocks containing these deposits were identified [14].…”