碩士 / 國立臺灣大學 / 海洋研究所 / 106 / The Southern Longitudinal Trough (SLT) is a N-S trending elongated trough located between the southeastern part of the Central Range and the Luzon Arc offshore southeastern Taiwan. It is situated in the incipient arc-continent collision zone, and the GPS measurements suggest that 60% of the plate convergence is taken up by the crustal deformation in this region. So it is important to understand the structural features and their developments in SLT. In this study, we use multichannel seismic reflection profile data together with high resolution bathymetry data, to study the topography changes and their relations with basement structures in SLT.
Morphology, the Southern Longitudinal Trough is enclosed by the Hengchun Peninsula at the western side and the Huatung Ridge at the eastern side. Large amount of orogenic sediment were delivered from Taiwan mountain belt and formed submarine channel system in the Southern Longitudinal Trough. There are two main channels in this channel system: one channel starts from Taimali river onland, the other starts from Lijia river onland. Submarine channel system is more obvious in the northern area of the Southern Longitudinal Trough where is closer to mountain belt, whereas submarine plane is more clear in the southern area. Some sediments seem to overflow out of the Southern Longitudinal Trough into the Taitung Canyon through the topographic gaps of the Huatung Ridge.
The seismic stratigraphy reveals that the Southern Longitudinal Trough is filled by growth strata, which may also form the Huatung Ridge, and the western tilting growth strata are getting flat from deep to shallow. Two main seismic sequences are recognized in the Southern Longitudinal Trough. The lower seismic sequence is strongly deformed with the basement, therefore it is interpreted to be the pre-collision sequence. The upper seismic sequence shows continuous parallel seismic strata and onlap pattern upon the lower sequence. The tilting angle of the strata in the upper sequence reduce from deep to shallow and became flat near surface. Some normal faults developed in the upper sequence but those normal faults stop at the top of the lower sequence. We interpret those are characters of syn-collision sequence. Large amount of orogenic sediments deposits in the Southern Longitudinal Trough and form growth strata when the Southern Longitudinal Trough was uplifted by convergence. Those normal faults in the upper sequence probably resulted from overloading of overlying strata.
| Identifer | oai:union.ndltd.org:TW/106NTU05279015 |
| Date | January 2018 |
| Creators | Jheng-Kai Huang, 黃政愷 |
| Contributors | 劉家瑄 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 84 |
Page generated in 0.0018 seconds