Geology, geochemistry, mineralogy of Phayaung Taung, Patheingyi Township, Mandalay Division, Myanmar

Abstract

Myanmar is endowed with a diverse array of metallic and nonmetallic mineral deposits, a number of which have recently been developed as world-class mines. Tagaung Taung deposit north of Mandalay is a resource approximately 40 km from Mandalay City. The Phayaung Taung gold deposit from the Slate Belt is hosted in phyllite, schist, and quartzite. Mineralization is associated with the stockwork quartz vein system. Wall-rock silicic alteration by cryptocrystalline quartz or amorphous silica is dominant. Phyllic alteration is characterized by sericite, quartz, chlorite, and pyrite with disseminated hematite. Gold occurs in tourmaline-quartz and sulfide-bearing quartz veins. It is associated with pyrite and chalcopyrite as well as Au-Ag-Bi-Te ore assemblages of petzite, hessite, and tellurobismuth. The Phayaung Taung gold deposit shows typical mesothermal characteristics. Scanning electron microscopy with energy-dispersive X-ray analyses revealed the average gold content of electrum grains, i.e., 75.1 wt% Au, with grain sizes ranging from 3 to 40 µm. Moreover, secondary native gold grains were formed with hematite and iron oxides in secondary remobilized/deformed veins at strongly brecciated/oxidized zones. The association between gold and altered sulfides suggests that gold was refractory in sulfides. It can be considered that supergene oxidation extended to deep mineralization veins. Such gold grains had the highest Au content, and are often in almost pure condition. This study discussed the geology, geochemistry, and mineralogy of the Phayaung Taung gold mine in Myanmar. New minerals were identified in the samples obtained from the study area, which were subjected to multiple analyses to determine their properties and understand the relationships between them.