PETROLOGY AND STRUCTURES OF VOLCANOCLASTIC SEDIMENTARY ROCKS AND IGNEOUS ROCKS IN SHINMATAUNG AREA, PAKOKKU TOWNSHIP, MAGAWE REGION
Abstract
- The study Shinmataung area situated between latitudes (21º 33’ to 21º 37’) N and longitude (95º 4’ to 95º 10’) E. Volcanic eruption might occur during and after the time of deposition of Irrawaddy Formation. Bender (1983) stated that west zone of “Pegu - Mt. Popa Line” begins south of Kabauk Village in the Shinmataung area and runs for about 100km with width of up to 18km via Salingyi, Silaungtaung and Twintaung to Natyintaung in the N. The lower Chindwin volcanic including Shinmataung area is situated north of Mt-popa and NNW striking section of the Central Volcanic Arc. The rocks are Tertiary in age except the igneous rocks of Salingyi area. Igneous rocks of the study area are rhyolitic agglomerate, breccia, diorite, olivine basalt, andesitic tuff and altered andesite. During the Miocene to sub-recent time, episodes of intermittent volcanic activity have been firstly recognized in the present area. The first phase was the extrusion of andesites. This activity appears to have been followed by the violent activity going rise to andesitic tuff-cones associated with rhyolitic agglomerate and breccia. Igneous rock units are also occurred in the western part of the present study area. These rock units are occurred isolated cone shaped hill half miles east of Kabauk village and Thardon- U hill about one mile south east of Kabauk. Moreover, dacite, fine-grained igneous rock also occurred in the valley between Taungnigyi and Shinmataung hill. Igneous rock units hill, lying nearly parallel to the Shinmataung hill, The study area (Shinmataung) is located in the Central Cenozoic Belt of Myanmar. Geologically, it is situated on the northeastern most edge of the Minbu Basin. This basin is a kind of gradually subsiding geosyncline related to subduction of India Plate beneath the Burma Plate in which tremendous thickness of clastic sediments were deposited during Oligocene to Pliocene?. The Shinmataung area is located in Yesagyo Township, Pakokku District, situated between are separated by a fault valley. Contact between igneous and sedimentary rocks can be noted beside Taunggya-Kabauk cart tract. In the Shinmataung area is the contemporaneous volcanic intercalations towards the base of the Oligocene and towards the upper limit of the composed strata.These volcanic rocks have been recorded as Miocene age in the present study area.
Collections
Download
Year
- 2020
Author
-
Yu Yu San
Subject
- Geology
Publisher
- Myanmar Academy of Arts and Science (MAAS)