Prospecting at the Minamisenno Ore Deposit of the Nakatatsu Mine

Abstract

Pyrometa somatic lead-zinc deposits of the Nakatatsu mine consist of five main ore deposits. Minamisenno, one of these ore deposits, has been prospected since 1955. As a result of this prospecting severeral new lead-zinc deposits with molybdenite and chalcopyrite, and two magnetite deposits have been discovered. Predominant contact minerals associated with these deposits are hedenbergite and garnet. Ore deposition is structurally contrrolled, as the ore is found in the outer side of shale or sandstone in limestone layers, in the axis of folding, in the fructured zone, and in the boundary between limestone and shale or sandstone. The mineralization is closely related to the quartz-porphyry. The magnetite deposits occur in the inner zone of the skarn masses adjacent to the quartz-porphyry, and sphalerite and galena deposits are found in the outer zone. An appreciable amount of molybdenite is disseminated throughout the skarn zone.