GRANULOMETRIC ANALYSIS OF DEPOSITIONAL ENVIRONMENT FROM YAW FORMATION EXPOSED IN PIN DAUNG TAUNG – THA LAUK AREA, CHINDWIN BASIN
Abstract
- The research area lies within the Chindwin Basin, which is filled by the Cretaceous to Miocene clastic sedimentary rocks which are deposited between the marine to fluvial conditions. The Yaw Formation mainly consists of thin to medium-bedded, grey to bluish-grey carbonaceous silty shale and nodular clay with some intercalated buff-yellowish sandstones. Coal seams are also interlayers with silty clay and sandstones. The Yaw Formation fall litharenites and the textural parameter shows unimodal, moderately to poorly sorted, nearly symmetrical to very positive skewness, mesokurtic to leptokurtic values that indicate fine to medium grains which are low to medium energy of current velocity condition. Bivariate plot of the standard deviation & median diameter distinguished between the river/wave and quiet water condition. Moreover, The PQ/OP segments of the CM pattern describe graded suspension with some rolled sediments as well as the segments QR point to saltation population and the grains size analysis as three populations. The log-probability curve of Yaw Formation sediments also supports the segments of the CM pattern. This indicates that the sediments of the Yaw Formation were transported and deposited in the different modes of saltation/suspension. According to petrography and grain size distribution, the sandstones of the Yaw Formation may be deposited at the low to medium energy state of the deltaic condition in shallow marine environments.
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Year
- 2022
Author
-
Htay Maung
Subject
- Chemistry, Physics, Zoology, Botany and Marine Science, Geology
Publisher
- Myanmar Academy of Arts and Science (MAAS)