碩士 / 國立臺灣大學 / 海洋研究所 / 85 / Taiwan is in the sutural zone between the Eurasian Plate and the
PhilippineSea Plate. The collision of these two plates presents
today''s Taiwan topography. Thus, the investigations of the
interaction between plates'' motion can be achieved by studying
the topographical features of the southern Taiwan region. By
using the topographic DTM data, the mechanism of orogeny under
the tectonical processes exerted in southern Taiwan is studied
in this thesis. The conclusions are also supported by the
seismic reflection profiles as well as the distribution map of
the earthquake epicenters. Onland of southeastern Taiwan, there
is a series of the ridges orientating in arc-shaped geometry
aligned in the E-W direction. These ridges extend offshore
eastward and develop in the basement of the Southernn
Longitudinal Trough as well as through the Hutung Ridge (HR).
These arcs share an geometric center geographically, implying
that a unique straining process controls the genesis of these
ridges. The continuity of the arc-shaped ridges in southeastern
Taiwan denotes the boundary between the plates should be located
in the east bounds of the HR.By the lineation analysis of the
topography, it is indicated that three sets of rupture zone are
detected. One of the sets is in the NW-SE direction crossing the
land into the ocean. From 22°40''N to the north, the Taitung
Trough(TT) presents an extensional left-lateral strike-slip
motion; to the south, it transforms as a compressional left-
lateral strike-slip mechanics. In addition, there are two right-
lateral strike-slip faults crossing through the north and the
south part of the TT. The processes imply a clockwise rotation
tectonically in the southeastern Taiwan region.As to the
geometric center of the arc-shaped ridges, it''s location can be
identified by the cluster of earthquake epicenters in the
region; however, by comparing among the orientations of three
sets of rupture zone, the distribution of earthquake epicenters,
and the location of the geometric center, it points out that the
center of the arc-shape ridges is a place of stress
concentration, and the stress has been migrated toward the
north.The orogeny of arc-shaped ridges resulting from the
collision between the Philippine Sea Plate and the Eurasian
Plate is proposed. This dynamics produces a concentrated stress
in the southeastern Taiwan, then propagating the stress to its
surroundings. Stress propagation/relaxation makes up a series of
arc-shaped ridges, and these ridges have the higher elevations
as they locate close to the compressional geometric center.
| Identifer | oai:union.ndltd.org:TW/085NTU00274018 |
| Date | January 1997 |
| Creators | Liu, Pei-Kun, 劉佩琨 |
| Contributors | Song Gwo-Shyh, 宋國士 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 97 |
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