At the mines of Apatit Combine, using a system of storey forced caving, in the blocks mined under the previously extinguished horizons, the definition of ore losses is complicated due to the transfer of beaten substandard ore and losses from the upper blocks. ...

Rock fracturing is a general property of a rock massif characterized by ubiquitous distribution and irregularity of development, as well as a pronounced average orientation of fracture systems within geological structures. The intensity of fracturing is determined, as observations show, by the composition of rocks and conditions of their occurrence. The aggregate of fracturing of individual layers, strata and stratigraphic horizons gives the fracturing of the rock massif. Being an important structural element of the rock massif, rock fracturing, especially in the conditions of folded coal deposits, is a constantly acting factor on the development conditions.

When developing disturbed areas of coal deposits, it is often necessary to deal with the assignment of exploratory or opening mine workings on a displaced wing of the seam. When a fault device encounters mine workings driven along the seam, one wing of the seam, carrying these workings, is a known wing in the solution of the specified problem, and the other is a displaced wing relative to the known or displaced wing. The solution of this and other geometric problems when working on disturbed areas - before exploration or opening of the sought (displaced) wing - is based on the assumption that the displaced wing is parallel to the known wing. Before solving the problem, it is necessary to establish the type of displacement encountered and select the direction of the working opening the displaced wing. To do this, it is necessary to know the vector of the "true" relative displacement of the displaced wing or the amplitude of the displacement in a certain direction, established by exploration. Strokes, furrows, potholes and crush halos on the plane of the fault device, as well as wing turns near cracks can serve as signs indicating the direction of movement of the "lost" wing, and can be used to determine the type of displacement and select the direction that opens the desired wing of the working.

When developing coal deposits, seams and associated mine workings are depicted on plans and sections. A seam plan and a vertical cross-section across the strike of rocks through the opening workings are mandatory components of a set of basic mine surveying plans for any conditions of coal seam occurrence. In conditions of steep seam dip, in addition to the above, a vertical projection of the seam onto a vertical plane passing through a line parallel to the dominant strike of the seam is also necessarily drawn up. When developing a group of inclined and steeply dipping seams, a horizontal section ("horizon" plan) is also drawn up with an image of the seams, capital and main development workings on it. On the listed mine surveying plans and sections - the main technical documents of the mine - the conditions of seam occurrence, and consequently, fault dislocations (displacements) must be properly reflected. A number of mandatory requirements are imposed on the specified documentation, contained in the current instructions and symbols.

Among the developed coal deposits of the USSR, the Suchan deposit is one of the most complicated by geological features and mining and operational factors. It is characterized by the following main features. The deposit is strongly dislocated. Pliquefactive and disjunctive tectonics is sharply expressed. Coal seams (as horizons) are pronounced but variable in thickness and quality. The coal-bearing strata along the weakening planes are cut by eruptive rocks with manifestations of contact metamorphism. Due to the fact that anticlinal parts of the folds are denuded to a large extent, the developed coal seams are contained in synclinal parts of the folds. It is of undoubted interest to find out from the exploitation data the distribution of displacements and the forms in which they appear in these conditions.

The described displacements belong to a special type of fault tectonics, which occurs in cover structures and develops in them as a result of movements of the underlying rigid base. Therefore, displacements of this type are of interest as a characteristic example of tectonics manifestation in the coal-bearing strata of the Lower Tertiary age. A general idea of ​​the nature of the manifestation of displacements is given by the schematic map of displacements and outcrops of coal seams (Fig. 1) and the geological section (Fig. 2). The coal-bearing strata of the Lower Tertiary age (Fig. 2) unconformably lies on the eroded surface of Mesozoic rocks. It is composed mainly of sandy clayey rocks. The underlying Mesozoic rocks in the area of ​​contact with coal-bearing deposits are represented by destroyed conglomerate and quartz-feldspar sandstones.