HR: 0800h
AN: T51A-1310    [Abstracts]
TI: Internal Structure of Taiwan Chelungpu Fault Zone Gouges
AU: * SONG, Y
EM: song@nsrrc.org.tw
AF: National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu, 30077 Taiwan
AU: Song, S
EM: srsong@ntu.edu.tw
AF: Department of Geosciences, National Taiwan University, P.O. Box 13-318, Taipei, 106 Taiwan
AU: Tang, M
EM: mautsu-nsrrc.org.tw
AF: National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu, 30077 Taiwan
AU: Chen, F
EM: frchen@ess.nthu.edu.tw
AF: Department of Engineering and System, Naitonal Tsing-Hua University, 101 Sec. 2,Guangfu Road, Hsinchu, 30043 Taiwan
AU: Chen, Y
T51A-1310 AF: National Synchrotron Radiation Research Center, 101 Hsin-Ann Road, Hsinchu, 30077 Taiwan
AB: Gouge formation is found to exist in brittle faults at all scale (1). This fine-grain gouge is thought to control earthquake instability. And thus investigating the gouge textures and compositions is very important to an understanding of the earthquake process. Employing the transmission electron microscope (TEM) and a new transmission X-ray microscope (TXM), we study the internal structure of fault zone gouges from the cores of the Taiwan Chelungpu-fault Drilling Project (TCDP), which drilled in the fault zone of 1999 Chi-Chi earthquake. This X-ray microscope have installed at beamline BL01B of the Taiwan Light Source, National Synchrotron Radiation Research Center (NSRRC). It provides 2D imaging and 3D tomography at energy 8-11 keV with a spatial resolution of 25-60 nm, and is equipped with the Zernike-phase contrast capability for imaging light materials. In this work, we show the measurements of gouge texture, particle size distribution and 3D structure of the ultracataclasite in fault gouges within 12 cm about 1111.29 m depth. These characterizations in transition from the fault core to damage zone are related to the comminuting and the fracture energy in the earthquake faulting. The TXM data recently shows the particle size distributions of the ultracataclasite are between 150 nm and 900 nm in diameter. We will keep analyzing the characterization of particle size distribution, porosity and 3D structure of the fault zone gouges in transition from the fault core to damage zone to realize the comminuting and fracture surface energy in the earthquake faulting(2-5).The results may ascertain the implication of the nucleation, growth, transition, structure and permeability of the fault zones(6-8). Furthermore, it may be possible to infer the mechanism of faulting, the physical and chemical property of the fault, and the nucleation of the earthquake. References 1) B. Wilson, T. Dewerw, Z. Reches and J. Brune, Nature, 434 (2005) 749. 2) S. E. Schulz and J. P. Evans, Tectonophysics 295 (1998) 223. 3) A. M. Boullier, K. Fujimoto, T. Ohtani, G. Roman-Ross, ? Lewin and H. Ito, P. Pezard, B. Ildefonse, Tectonophysics 378 (2004)v165. 4) Z. K. Shipton and P. A. Cowie, J. Structural Geology 25 (2003) 333. 5) J. S. Chester, F. M. Chester and A. K. Kronenberg, Nature 437, (2005) 133. 6) A. Billi, F. Salvini and F. Storti, J. Structural Geology 25 (2003)1779. 7) J. S. Caine, J. P. Evans and C. B. Forster, Geology 24 (11) (1996)1025. 8) N. Nakimura, T. Hirose and G. J. Borradaile, Earth and Planetary Science Letters 201 (2002) 13.
DE: 8010 Fractures and faults
DE: 8030 Microstructures
DE: 8118 Dynamics and mechanics of faulting (8004)
SC: Tectonophysics [T]
MN: Fall Meeting 2005