Abstract

• The Shwebontha area is located about one-kilometer ENE of the Letpadaung Cu-Au deposit. This study is aimed to investigate and characterize the geological condition, rock, alteration and ore mineralization. The geology of the Shwebontha area consists of volcanic and volcaniclastic rocks of the Late Oligocene to Middle Miocene Magyigon Formation that served as the host rocks of ore mineralization. Geochemically, the volcanic rocks having calc-alkaline nature and they are classified as volcanic field (rhyolite). Three types of alteration are developed in vicinity of mineralized quartz veins including silicic, argillic, and propylitic alteration zones. Mineralization is characterized by gold-bearing silicified massive ore and chalcedonic quartz vein in rhyolite host rocks. Optical microscopy and X-ray diffractometer (XRD) analysis indicate that these veins typically contain several ore mineral assemblage such as pyrite, sphalerite, galena, chalcopyrite, gold, covellite, goethite and hematite, associated with gangue mineral characterized by quartz, calcite, chlorite/epidote and clay minerals. Based on the current available data from hydrothermal alteration, mineralization types and ore mineral assemblages from the Shwebontha area develops forming under an epithermal environment.