ABSTRACT : In this study, geomechanical properties of the soil units which forms the Mgnitic series in Erzurum- Horasan-Ali çeyrek area are investigated, furthermore expected soil behavior during mining excavations and the applicability of some mining methods are discussed from the geotechnical point of veiw. From the geotechnical point of view» days in the area investigated, show relatively durable, highly plastic.» nonsensitive and montmoriUonitic character. On the other hand,,, sands generally form loose» uniform and weak soils however` show medium to veak properties. Studies carried out on. clay soils indicate some positive behaviors such as soundness, relatively long term, unsupported stand-up time with the exception, of medium-high swelling potential. In, loose sand horizons, especially below the groundwater level» -ravelling» running` and short term unsupported stand-up time behaviors should be expected. Therefore, the occurance of some limitations ought to be considered for the applicability of underground mining methods, in. the area. In the case of applying open pit method,» loose sand, horizons are` considered as one of the most important factors controlling the stability. Thus, final pit slopes should be designed with angles flatter than. 45 degrees. In addition » because of the long` duration of mining aperations and determined, geomechanical properties of cohesive soils in the area, long` term stability would be most critical stability condition and should be öncluded in the investiga- - tions of slope stability.