2026-05-04T08:50:00Z https://meral.edu.mm/oai

oai:meral.edu.mm:recid/282 2021-12-13T03:03:55Z 1582963788001:1582966668038 user-ydbu

Occurrences of the Kalaw formation in Yimi Area, Pinlaung Township, Southern Shan State Dr.Thaire Phyu Win Daw Khin Yuzana Win The present study area is situated in the Pinlaung Township, southern Shan State. The study area lies in the southern part of the Kalaw-Pinlaung Basin. It comprises the Plateau Limestone Group of Permian to Triassic age, Loi-an Group of Jurassic age, and Kalaw Formation of Cretaceous age. The Kalaw Formation can be subdivided into three members. The lower member of Kalaw Formation is an interbedded unit consisting of thin- to medium- bedded red sandstone, siltstone and shale. The good exposure of this member can be observed around the environs of Yegauk, Danrwe, Pinle and south of U-saung village and along the Pinlaung-Naypyitaw Car road. The middle conglomerate-sandstone member is an interbedded interval of medium- to thick-bedded, polymictic conglomerates and thin- to medium-bedded red siltstone and sandstone. Planar cross-beddings, pebble imbrication and gradded bedding occur in this member. This member well crops out near Htibwa Anau village, Yegauk monestry, near U-saung and along the Pinlaung-Naypyitaw Car road section. The upper member is a unit of thick-bedded to massive, hard, dark purplish to dark grey conglomerate intercalated with red siltstone.The conglomerates are poorly sorted and consist of limestone, dolomitic limestone, chert, red sandstone, and buff coloured sandstone pebbles which are cemented by red silt and sand. Upper conglomerate exposes near Zarka, Kyaungso, Ngwedaung, Htibwa Anau, Kondon, Shadein, Usaung, and near Yegauk villages.No fossil has been found from this formation in the study area. This unit unconformably overlies the Loi-an Group and the Plateau Limestone Group. On the basic of lithologic characters and stratigraphic position, the Kalaw Formation can be correlated with the Kalaw Formation of Khin Maung Win (1978), and Kalaw Red beds of MaungThein (2014). Therefore the age of the Kalaw Formation is thought to be taken as Cretaceous age.The sandstones of Kalaw Formation fall in the field of "Litharenite and Arkose" according to Pettijohn et.al, (1987) and it might be the deposit of large rivers, either alluvial or delta. It may be interpreted the conglomerate beds of the study area may be deposited as the alluvial or fluvial fan deposits. 2017 http://hdl.handle.net/20.500.12678/0000000282 https://meral.edu.mm/records/282