Abstract

• The research area is located in Chaung Zon Village, Pwintbyu Township, Magway Region. Okhmintaung Formation is characterized by light grey, medium to coarse grained, thick bedded to massive type sandstones intercalated with thin-bedded mudstones and bluish grey shales are also occurred. The sandstones of the Okhmintaung Formation may be termed as “Sublithicarenite”. Alteration of biotite to muscovite and oxidized biotite are more common in the Okhmintaung sandstone in the study area. The cementing material in the Okhmintaung sandstones are calcite and iron cements, glauconite, rutile and clay matrix. The common characteristics of late burial or phyllomorphic stage are the alteration of clay mineral into micas and the development of well crystallized phyllosilicate minerals.