Active deformation of the Central Myanmar Forearc Basin : insight from post-Pleistocene inversion of the Pyay Fault

Pyay sub-basin is located in the southern part of the Central Myanmar Forearc Basin, an elongate belt of en-echelon folds and thrust faults formed as a result of the hyper-oblique convergence of the India and Asia plates. Limited neotectonic studies suggest that the Pyay Fault is a major Pliocene in...

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Main Authors: Aung, Lin Thu, Oo, Kyaw Zin, Win, Kyaw Myo, Moore, Gregory F., Tun, Soe Thura, Naing, Win
Other Authors: Earth Observatory of Singapore
Format: Article
Language:English
Published: 2021
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Online Access:https://hdl.handle.net/10356/146016
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spelling sg-ntu-dr.10356-1460162021-01-23T20:10:50Z Active deformation of the Central Myanmar Forearc Basin : insight from post-Pleistocene inversion of the Pyay Fault Aung, Lin Thu Oo, Kyaw Zin Win, Kyaw Myo Moore, Gregory F. Tun, Soe Thura Naing, Win Earth Observatory of Singapore Social sciences::Geography Central Myanmar Forearc Basin Pyay Fault Pyay sub-basin is located in the southern part of the Central Myanmar Forearc Basin, an elongate belt of en-echelon folds and thrust faults formed as a result of the hyper-oblique convergence of the India and Asia plates. Limited neotectonic studies suggest that the Pyay Fault is a major Pliocene inverted structure that trapped the hydrocarbons in Pyay sub-basin, where only sparse field-based observations are available to address the nature of very recent neotectonic processes. This study focuses on structural deformation related to active inversion of the Pyay Fault using field-based geological observations and interpretations of industrial seismic data. We map the ∼105 km long Pyay Fault, an east- dipping high-angle reverse fault with a significant dextral strike-slip component. The fault underlies the western limb of the major NNW-SSE- striking anticlinal ridge that forms the western margin of Pyay sub- basin. Growth strata within the Pliocene-Pleistocene Irrawaddy Formation, imaged in the shallow part (<1 km) of 2D seismic profiles, reflects the deposition of Pliocene-Pleistocene sediments synchronously with the inversion of the underlying Pyay Fault. In addition, uplifted fluvial terraces of the Ayeyarwady River on the hanging wall of Pyay Fault reflect the post-Pleistocene inversion of the Pyay sub-basin. This study suggests that the Pyay Fault is a prime example of active deformation of the Central Myanmar Forearc Basin which plays an important role in the basin evolution and an earthquake source potential of the Myanmar territory. Ministry of Education (MOE) National Research Foundation (NRF) Published version This work is a part of the first author’s Ph.D. dissertation at the University of Yangon, Myanmar. The first author would like to thank to U Thit Lwin, Pyay University and his graduate students for their help in various ways during the field work. The authors would like to express sincere appreciation to Prof. Punya Charusiri, Chulalongkon University and Dr. Jonathan R. Weiss, University of Potsdam for their reviews that greatly improved the quality of this manuscript. Our thanks are also extended to Prof. Khin Zaw, University of Tasmania for handling the manuscript and editorial input. We also thank Dr. Kyaw Linn Oo, Petronas Myanmar Exploration and Dr. Wang Yu, National Taiwan University for their comments on an earlier draft. Field surveys for this work were partially supported by Resource and Environment Myanmar Ltd. and Myanmar Earthquake Committee. This research was supported by the Earth Observatory of Singapore via its funding from the National Research Foundation Singapore and the Singapore Ministry of Education under the Research Centres of Excellence initiative. This work comprises EOS contribution number 343. 2021-01-21T03:31:08Z 2021-01-21T03:31:08Z 2020 Journal Article Aung, L. T., Oo, K. Z., Win, K. M., Moore, G. F., Tun, S. T., & Naing, W. (2020). Active deformation of the Central Myanmar Forearc Basin : insight from post-Pleistocene inversion of the Pyay Fault. Journal of Asian Earth Sciences: X, 4, 100037-. doi:10.1016/j.jaesx.2020.100037 2590-0560 https://hdl.handle.net/10356/146016 10.1016/j.jaesx.2020.100037 2-s2.0-85097799014 4 en Journal of Asian Earth Sciences: X © 2020 Earth Observatory of Singapore, Nanyang Technological University. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Social sciences::Geography
Central Myanmar Forearc Basin
Pyay Fault
spellingShingle Social sciences::Geography
Central Myanmar Forearc Basin
Pyay Fault
Aung, Lin Thu
Oo, Kyaw Zin
Win, Kyaw Myo
Moore, Gregory F.
Tun, Soe Thura
Naing, Win
Active deformation of the Central Myanmar Forearc Basin : insight from post-Pleistocene inversion of the Pyay Fault
description Pyay sub-basin is located in the southern part of the Central Myanmar Forearc Basin, an elongate belt of en-echelon folds and thrust faults formed as a result of the hyper-oblique convergence of the India and Asia plates. Limited neotectonic studies suggest that the Pyay Fault is a major Pliocene inverted structure that trapped the hydrocarbons in Pyay sub-basin, where only sparse field-based observations are available to address the nature of very recent neotectonic processes. This study focuses on structural deformation related to active inversion of the Pyay Fault using field-based geological observations and interpretations of industrial seismic data. We map the ∼105 km long Pyay Fault, an east- dipping high-angle reverse fault with a significant dextral strike-slip component. The fault underlies the western limb of the major NNW-SSE- striking anticlinal ridge that forms the western margin of Pyay sub- basin. Growth strata within the Pliocene-Pleistocene Irrawaddy Formation, imaged in the shallow part (<1 km) of 2D seismic profiles, reflects the deposition of Pliocene-Pleistocene sediments synchronously with the inversion of the underlying Pyay Fault. In addition, uplifted fluvial terraces of the Ayeyarwady River on the hanging wall of Pyay Fault reflect the post-Pleistocene inversion of the Pyay sub-basin. This study suggests that the Pyay Fault is a prime example of active deformation of the Central Myanmar Forearc Basin which plays an important role in the basin evolution and an earthquake source potential of the Myanmar territory.
author2 Earth Observatory of Singapore
author_facet Earth Observatory of Singapore
Aung, Lin Thu
Oo, Kyaw Zin
Win, Kyaw Myo
Moore, Gregory F.
Tun, Soe Thura
Naing, Win
format Article
author Aung, Lin Thu
Oo, Kyaw Zin
Win, Kyaw Myo
Moore, Gregory F.
Tun, Soe Thura
Naing, Win
author_sort Aung, Lin Thu
title Active deformation of the Central Myanmar Forearc Basin : insight from post-Pleistocene inversion of the Pyay Fault
title_short Active deformation of the Central Myanmar Forearc Basin : insight from post-Pleistocene inversion of the Pyay Fault
title_full Active deformation of the Central Myanmar Forearc Basin : insight from post-Pleistocene inversion of the Pyay Fault
title_fullStr Active deformation of the Central Myanmar Forearc Basin : insight from post-Pleistocene inversion of the Pyay Fault
title_full_unstemmed Active deformation of the Central Myanmar Forearc Basin : insight from post-Pleistocene inversion of the Pyay Fault
title_sort active deformation of the central myanmar forearc basin : insight from post-pleistocene inversion of the pyay fault
publishDate 2021
url https://hdl.handle.net/10356/146016
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