HR: 09:05h
AN: T11A-05 INVITED     [PDF]
TI: Tectonics of the Ailao Shan-Red River Fault Belt in East Asia
AU: * Lee, T
EM: t44001@cc.ntnu.edu.tw
AF: Department of Earth Sciences, National Taiwan Normal University, 88, Section 4 Ting-Chou Road, Taipei, 116 Taiwan
AU: Yeh, M
EM: porphyroblast@yam.com
AF: Department of Earth Sciences, National Taiwan Normal University, 88, Section 4 Ting-Chou Road, Taipei, 116 Taiwan
AU: Lo, C
EM: loch@ccms.ntu.edu.tw
AF: Department of Geosciences, National Taiwan University, 1, Section 4 Roosevelt Road, Taipei, 106 Taiwan
AU: Chung, S
EM: sunlin@ccms.ntu.edu.tw
AF: Department of Geosciences, National Taiwan University, 1, Section 4 Roosevelt Road, Taipei, 106 Taiwan
AU: Lan, C
EM: kyanite@earth.sinica.edu.tw
AF: Institute of Earth Sciences, Academia Sinica, 128, Section 2 Academia Road, Taipei, 115 Taiwan
AU: Wu, H
EM: wuhh@geps.gep.ncu.edu.tw
AF: Institute of Geophysics, National Central University, 300, Jung-Da Road, Jung-Li, 320 Taiwan
AU: Tsai, Y
EM: ybtsai@geps.gep.ncu.edu.tw
AF: Institute of Geophysics, National Central University, 300, Jung-Da Road, Jung-Li, 320 Taiwan
AU: Hu, J
EM: jchu@ccms.ntu.edu.tw
AF: Department of Geosciences, National Taiwan University, 1, Section 4 Roosevelt Road, Taipei, 106 Taiwan
AB: The Ailao Shan-Red River (ASRR) fault belt is one of the most profound active strike-slip faults in East Asia. It is generally believed that the Cenozoic India-Eurasia collision caused the southeastward extrusion of Indochina along the ASRR fault belt (left-lateral displacement) in mid Tertiary. However, geomorphologic evidences and earthquake focal mechanism solutions do indicate a present-day right-lateral slip of the ASRR. Structural analyses and field observation along the ASRR in northern Vietnam revealed that the ASRR has undergone multiple phases and styles of deformation (three ductile folding events with a younger brittle deformation) possibly since Triassic to Pliocene. The deformation history, combined with offshore exploration data and igneous activities, enabled us to better constrain the tectonic evolution of the ASRR. A previously unrecognized deformation event (D1) with foliations showing dextral sense of shear possibly formed during the Triassic Indosinian orogeny or during Eocene post India-Eurasia collision. D2 is the strongest deformation event within the ASRR forming large-scale horizontal folds possibly commenced since Eocene-Oligocene as the thickened ductile crust flowed eastwardly away from the Tibetan Plateau under SE Asia, and extended to Early Miocene till termination of sinsitral strike-slip movement of the ASRR. D3 continuously uplifted most of the ASRR and formed current antiformal domes in northern Vietnam with NW-SE subvertical fold axial planes parallel to the trend of ASRR, possibly due to the right-lateral movement of the ASRR during Late Miocene to Pliocene. Continuous denudation uplifted the ASRR crossing the brittle-ductile transition zone forming brittle structures (D4) as the right-lateral movement of the ASRR continued.
DE: 8000 STRUCTURAL GEOLOGY (New field, replaces single entry 8165)
DE: 8005 Folds and folding
DE: 8100 TECTONOPHYSICS
DE: 8107 Continental neotectonics
DE: 8123 Dynamics, seismotectonics
SC: Tectonophysics [T]
MN: 2003 Fall Meeting