HR: 1330h
AN: T12C-0476    [PDF]
TI: Geomorphic Indicators and Tectonic Implications of the Active Chaochou Fault, Southern Taiwan
AU: * Hung, J
EM: jhung@earth.ncu.edu.tw
AF: Institute of Geophysics, National Central University, Institute of Geophysics, National Central University, Chungli, 320 Taiwan
AU: Liao, H
EM: jhung@earth.ncu.edu.tw
AF: Institute of Applied Geology, National Central University, Institute of Applied Geology, National Central University, Chungli, 320 Taiwan
AB: The Chaochou Fault, lying on the easternmost edge of the Pingtung plain, is the major geologic boundary between the Slate Belt to the east and the Western Foothills to the west. According to previous studies, the Chaochou fault is a high-angle reverse fault dipping 75-80 degrees to the east. Along strike, several transverse rivers cut across the fault and form alluvial fans in the foothills, which provide unique morphotectonic features to study the activity of the Chaochou Fault. Digitized data from topographic maps of 1/5,000 to 1/25,000 scales and digital elevation data of 40m resolution were input into GIS software and analyzed to quantitatively evaluate geomorphic indicators such as hypsometric integral, stream length-gradient index and drainage basin asymmetry etc. Anomalies of these indices are further checked in the field on bedrocks, man-made structures and fold and faults, to clarify spatial variations of indicators. These, coupled with GPS data, field survey in the slate belt and uplifted terraces and subsurface seismic profiles, can further constrain spatial and temporal kinematics of the Chaochou fault and the relationship between topographic evolution and subsurface structures. Our preliminary results show that river landforms are highly related to the Chaochou Fault. Drainages were tilted to the west in response to uplifting in the east of the Chaochou Fault. Geomorphic indices indicate that the uplift rate is higher in the north and decreases progressively toward the south. The peak tectonic activity occurs in the area between the Chaochou and the Chishan Fault.
DE: 1744 Tectonophysics
DE: 1824 Geomorphology (1625)
SC: Tectonophysics [T]
MN: 2003 Fall Meeting