「地震及活斷層研究」－地震地質─車籠埔斷層活動相關之光螢光法年代學研究(2/2)

This proposal will focus on age determination,
which is eagerly needed in the integrated project
“Earthquake Geology and Kinematics of Active
Faults”. Adopted method is Optical Stimulated
Luminescence (OSL) method, which has been rapidly
developed during 90’s. Hopefully the advantage of
this method in dating limit can help us extending our
knowledge into much older past. It is also expected
that the advantage in sampling would fill up age void
during late Pleistocene.
The major subjects on earthquake geology and
kinematics of active fault are recurrence interval of
coseismic faulting and long-term slip rate. These time
related subjects need to cooperate with useful
geochronological study. In the past, radiocarbon
method was commonly used; however, its short dating
limit and restricted sample requirement made widely
using unable. On the other hand, recent progress on
OSL method seems able to make up these deficiencies.
Its oldest limit can reach 150ka. Its dating materials
are common minerals that are widely distributed
elsewhere in sediments. Furthermore, not like TL
method, it is applicable to sediments collected from
different sedimentary environments. One more
advantage worthwhile to mention is its highly efficient
analyzing processes. It further results in a relative low
cost. All these above-mentioned advantages indicate
that the OSL method is unequivocally useful.
During the coming year, this project plans to
firstly collaborate with the other principal
investigators who are working paleoseismology, the
trenching excavation along the chelungpu fault. The
second goal is to work on samples collected from
river terraces, which can provide more age data to
decipher the neotectonics in central Taiwan.
Hopefully, this project can provide at least 150 OSL
ages in coming three years to help understanding more
details regarding to earthquake geology and
kinematics of active faults in central Taiwan.