Abstract

• Kyauktap area, the study area is situated about 17 kilometres north of Heho, Kalaw Township, Taunggyi District. Regionally, the Precambrian rocks of Chaungmagyi Group are surrounded by Lower Paleozoic rocks. The study area is located in the southern part of Bawsaing Range that lies in the southwestern part of the Shan Plateau. Sedimentary rocks of the Wunbye Formation, Nanon Formation of Pindaya Group (Ordovician age) and Linwe Formation of Mibayataung Group (Silurian age) cropped out in the study area. According to petrographic classification, Wunbye Formation can be divided into six microfacies: Oolitic Dolomatized Grainstone, Dolomitic Limestone, Crystalline Limestone, Oolitic-PelloidalGrainstone, Pelloidal-Bioclastic Wackestone, Micrite or Limemudstone, and Ferruginous Lime Mudstone of Linwe Formation. The lead mineralization is confined to the carbonate rocks of Wunbye Formation of Middle Ordovician age. Absence of igneous rocks is conspicuous. Two types of wallrock alteration are dolomitization as the main alteration, and silicification as subordinate, which predate the ore mineralization. The major ore minerals are galena and barite, and its associated minerals are sphalerite, pyrite, chalcopyrite, covellite and anglesite. The gangue minerals are calcite, dolomite and quartz. Both open-space fillings (veinlets, disseminations, fracture fillings and solution collapse breccias) and replacement (irregular patches to massive aggregates) styles are the nature of ore mineralization. Lead mineralizations are localized by both structural and lithostratigraphical controls.There are two occurrences of lead mineralization in the study area. Pb values range from 3.746% to 58.34%. The content of Zn ranges from 0.0% to 16.45%, Cu ranges from 0.0% to 0.024%, Ba ranges from 0.0% to 0.729% in the study area. Based on the geological, geochemical and mineralogical characteristics, the lead mineralizations in the study area are carbonate-hosted, stratabounddeposits, and epigenetic in origin and may be regarded as one of the sub-types of the Mississippi Valley-Type (MVT) deposits.