Abstract

• Carbonate microfacies analysis was systematically carried out focusing on the sedimentological characters for the rock units exposed in the area between Yatsawk and Bawsaing, Yatsawk township, Shan state (south), Myanmar. It lies between latitude 21° 03' N and 21° 07'N, longitude 96° 45' E and 96° 55'E, representing one inch topographic map index of 93 C/16. Most of the exposed rock units are limestone and dolomite with different lithologic characters in different geological age, with minor amount of clastic rocks. Detailed sedimentological analysis and interpretations are carried out for the Linwe Formation. It consists of purple, pink and grey, medium to thick bedded phacoidal limestones, fine-grained, poorly jointed, wavy and discontinuous laminated, argillaceous limestone, bluish-grey calcareous shale and calcareous mudstone. Based on the partical component, texture and sedimentary structure six microfacies such as lime mudstone, bioclastic lime mudstone, biointraclastic wackestone, bioclastic wackestone, bioclastic lithoclasticpackstone and bioclastic packstone are recognized. By the microfacies analysis, Linwe Formation can be subdivided into four different facies associations falling into four main depositional environments, namely, foreslope, open sea shelf, deep shelf margin and basin by identifying their grain type, physical, biologic and sedimentary structures.