HR: 1330h
AN: T12C-0488    [PDF]
TI: Holocene Multiple Movement of the Hsinhua Fault in Southwestern Taiwan
AU: * Lee, C
EM: ct@gis.geo.ncu.edu.tw
AF: Institute of Applied Geology, National Central University, ChungLi, 320 Taiwan
AU: * Lee, C
EM: ct@gis.geo.ncu.edu.tw
AF: Institute of Geophysics, National Central University, ChungLi, 320 Taiwan
AU: Liao, C
EM: app601@gis.geo.ncu.edu.tw
AF: Institute of Geophysics, National Central University, ChungLi, 320 Taiwan
AU: Lin, P
EM: person@gis.geo.ncu.edu.tw
AF: Institute of Geophysics, National Central University, ChungLi, 320 Taiwan
AU: Wen, S
EM: wsc@gis.geo.ncu.edu.tw
AF: Institute of Applied Geology, National Central University, ChungLi, 320 Taiwan
AB: Four trenches were excavated at the Hsinhua Fault in Napalin, Tainan. Rupture zone and multiple-paleoearthquake phenomena have been discovered in these trenches. In trenches NBL-2 and NBL-3, we have recognized the rupture plane and fissure-fillings which belong to the 1946 event. We shall extend the length of trench NBL-1 northward so that the 1946 rupture zone can also be opened there. These trenches involved several reference layers which include paleo-channel deposits, peat and paleosol at the vicinity of fault rupture zone. The channel deposits have been offset by the 1946 event, and also preserved older paleoearthquake events. At the base of the channel, open fissure and peat filling, which indicate an older earthquake event, were observed. Below the channel deposit, a layer of paleosol exists at top of the Holocene Tainan Formation. Cut relations and other phenomena indicate many much older events can be further analyzed. To give an overview, the Hsinhua Fault in the study area was situated at a transtensional tectonic environment. Apparent normal-fault features as shown on the trench walls might be a flower structure that often occurs in a strike-slip fault zone. Depression of present-day ground surface as well as paleo- topography in the vicinity of the fault rupture zone, and the development of paleo-channel may closely relate with the transtensional environment. Evidences show that at least three recent events have occurred during and after the Niauhsung cultural age (400-2000y.B.P.). More detailed results may come out after the age of reference materials have been dated.
DE: 7221 Paleoseismology
DE: 7223 Seismic hazard assessment and prediction
DE: 8005 Folds and folding
DE: 8010 Fractures and faults
DE: 8107 Continental neotectonics
SC: Tectonophysics [T]
MN: 2003 Fall Meeting