The bed of continuous ores has a benchlike structure due to the development of shearfault tectonics. The faulting consists of level and straight or slightly curved planes of slip. In some parts there are zones of increased jointing. Their thickness is 1-5 m. The azimuths of the strike of the faulting are 110-190 = , and the dips 60-90 = . Within the worked field of the Oktyabr' mine, except in the zones of intensive jointing, the continuous sulfide ores are regarded as only slightly faulted: The mean block dimension is 25 cm. During the construction of the Oktyabr' mine there were cases of dynamic breakage of the rock in workings driven near the periphery in metamorphosed argillites and marls. In the continuous ores during the first stage of development of the mine, the operations were accompanied by large-scale dynamic falls of the roof and sides in the form of flaking, intensive slip, bursts, and sudden caving, due to the high state of stress of the rocks. Using the method of complete stress relaxation, we investigated the state of stress of the rock: We found that the horizontal stresses average 400-600 kg/cm 2 and the vertical ones 200-300 kg/cm 2. The o~ientation of the stress components agrees with the tectonic deformations of the rocks. The minimum horizontal components are parallel to the tectonic faulting, and the maximum ones are normal to it. The nonuniformity of the stress field is due to the tectonics and to the mechanical properties of the rocks. We investigated the variation of the state of stress of the rock round a working, using complete load relaxation, insertion of an indentor into the face and walls of a borehole, electrometry, disk cores, and drillholes; we found that the zone of maximum stresses lies 0.5 to 3-4 m from the periphery of the working. The cause of dynamic breakage in the potentially shock-prone rocks is that near the periphery of the workings there are zones of high stress which reach or exceed the strength under uniaxial compression.