The Bukuk deposit is situated in the region of development of middle Jurassic marine deposit, Variscian granites and Post Jurassic granodiorites. The granodiorite intrusion probably corresponds to the pre-cretaceous folding having highly marked traces of activity in the Eastern Transbaikal. The forming of the ore in this region chiefly takes place in the granodiorite massif, in its central and endocontact parts. The orebodies are very seldom found in the sandy-shale masses of rocks. In the course of the genetic study of the Bukuk orebody it was found out that in the formation of the orebodies the magmatic solutions used the well developed fissility in the granodiorite. In the moment of the cooling of the latter, many joints of different directions were formed. Later on they were opened and changed into gently sloping or steep fissures of diaclase, which subsequently were changed into fissures of paraclase.