Abstract

• Myinhe Taung-Yasagyi area is located about 35 km southeast of Ywangan Township, Taunggyi District, Shan State (South). Regionally the study area mainly composed of sedimentary rocks of the Pindaya Group (Wunbye Formation) of Ordovician age, Mibayataung Group (Linwe Formation) of Silurian age and Plateau Limestone Group (Nwabangyi Formation) of MidPermian-Triassic. The Ganaingya fault is the major structure which is trending nearly NW-SE. The present research work involves the carbonate rocks of the Wunbye Formation (Middle Ordovicain age) which hosts the lead-zinc-copper ore mineralization. In the study area, four leadzinc-copper prospects are associated with the dolomitic limestone of Wunbye Formation. The lead sulfide mineralization is confined to the carbonate rocks of Wunbye Formation. The wallrock alteration zones are narrow, with dolomitization as the main alteration, and silicification as subordinate, which happen after the ore mineralization. The ore mineralogy is relatively simple where galena and barite form major constituents with minor amounts of sphalerite, pyrite, chalcopyrite, tetrahedrite , covellite, malachite and azurite. The gangue minerals are calcite, dolomite and quartz. Open-space fillings and replacement (irregular patches to massive aggregates) nature of ore mineralization are present. The lead-zinc-copper mineralization is localized by both structural and lithostratigraphical controls. Lead values range from 0.108% to 34.22% in Myinhe Taung near Yasagyi village. The contents of zinc range from 0.009% to 1.337%, copper ranges from 0% to 7.164% and barite ranges from 0% to 41.82% in the study area. Based on the geological, geochemical and mineralogical characteristics, the lead sulphide mineralizations in the study area are carbonate-hosted, stratabound, and epigenetic in origin and may be regarded as one of the sub-type of the Mississippi Valley-Type (MVT) deposits.