Application of an integrated methodology for forecasting tectonic disturbances to ensure safe open pit mining of apatite-nepheline ore deposits

Mining operations in complex mining and geological conditions with intensive structural and tectonic disturbance of the rock massif poses the primary task of accurate identification and prediction of tectonic disturbances and zones of structural weakening, as the most intense and dangerous manifestations of geodynamic processes are confined to the areas of their localization. In the present work the main provisions and peculiarities of practical application of the developed complex method of tectonic disturbance forecasting are considered. This methodology includes several stages: forecasting tectonic spaces based on initial geological exploration data, identifying tectonic spaces in order to check and create a three-dimensional model of tectonic spaces, which represent the boundaries of structuraltectonic blocks of various ranks. The list of geological factors influencing the stability of mine workings on the example of apatite-nepheline ore deposits of the Khibiny massif is given. The main regularities of the influence of structural and tectonic disturbance on the nature of related manifestations of accidents are characterized. The results of the analysis of the peculiarities of the tectonic structure of the considered deposits and field verification of the predicted tectonic disturbances are given. On the surface of the majority of these disturbances is fixed in the form of crushing or stratification zones, which show intensive development of hypergenic processes with formation of spreuerusteinization zones sustained along strike and dip. Dikes of intrusive rocks characteristic of fracture zones are confined to some of them. Displacements of geologic boundaries along the faults are rare. The results of forecasting of tectonic faults allow to determine more precisely the location and characteristics of tectonic faults, to reduce possible costs in order to ensure geodynamic safety of the field.The authors are grateful to Candidate of Geological and Mineralogical Sciences E. K. Melnikov, Candidates of Engineering Sciences N. V. Guseva and M. M. Idiyatullin for the preparation of initial factual material that served as a basis for developing this methodology.