HR: 11:05h
AN: T32B-04    [Abstracts]
TI: Paleoseismic Investigation of the Ranong and Khlong Marui faults, Chumphon Province, Southern Thailand
AU: * Fenton, C H
EM: c.fenton@imperial.ac.uk
AF: Department of Civil & Environmental Engineering, Imperial College, London, SW7 2AZ United Kingdom
AU: Sutiwanich, C
EM: chinda_s@panyaconsult.co.th
AF: Panya Consultants, 22 Ladprao 35,Ladyao, Jutujak, Bangkok, 10900 Thailand
AB: The Ranong and Khlong Marui faults are northeast-southwest trending structures in the Isthmus of Kra, southern Thailand, that apparently link the extensional regimes of the Mergui Basin in the Andaman Sea and the Gulf of Thailand. These faults are depicted commonly as strike-slip faults, acting as conjugate structures to the dominant northwest-southeast trending strike-slip faults, in Southeast Asia. These faults are parallel to the predominant structural grain in the Carboniferous rocks of peninsular Thailand. In addition, they appear to be bounding structures for several Tertiary basins, including the onshore parts of the Surat Thani basin and the offshore Chumphon basin. Initial remote sensing studies showed that both faults have relatively subdued geomorphic expressions. Field reconnaissance investigations indicated a lack of youthful tectonic geomorphology along the Khlong Marui fault and ambiguous evidence for recent movement along the Ranong fault. Fault exposures along both fault trends and on minor parallel faults in the region indicated that, rather than predominantly strike-slip motion, these faults have experienced up-to-the-west reverse movement. Because of its more youthful geomorphic expression, several sites along the Ranong fault were chosen for paleoseismic trenching. Initial trench exposures indicate an absence of Holocene movement. Some exposures indicate the possibility of Late Tertiary-Early Holocene vertical movement. These investigations are currently ongoing and we hope to report our conclusions at the Fall Meeting.
DE: 8002 Continental neotectonics (8107)
DE: 8036 Paleoseismology (7221)
DE: 8107 Continental neotectonics (8002)
DE: 8111 Continental tectonics: strike-slip and transform
DE: 8175 Tectonics and landscape evolution
SC: Tectonophysics [T]
MN: Fall Meeting 2005