Structure of Southern Central Range: Insights from A-Lan-Yi area

• Main Authors: Ching-An Lee, 李謦安
• Other Authors: Chia-Yu Lu
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/c7zf6d

碩士 === 國立臺灣大學 === 地質科學研究所 === 105 === Southern Taiwan, including Pingtung peninsula and Taitung, is the incipient oblique convergent zone of Eurasian plate and Philippine Sea plate. Subduction activity formed the Luzon volcanic arc and accretionary wedge offshore southern Taiwan. So that we can infer the incipient feature structure from the topography and outcrop study of southern Taiwan. Hengchun peninsula remained the structural evolution evidence about Taiwan as subduction zone to orogenic zone inside the accretionary wedge. Previous studies observed some mountain building history by analyzing the antiformal syncline and shear zone by the tomography and field survey along the Taimali to Jinlun coastline Such as east-vergent structures which formed the overturned formation and left lateral faults which caused by transpression process. In this study, we continued the former studies and integrate the records of the structure from the field survey to complete the structure evolution story. The field survey of this study is in the Reserve area from Nantien to Syuhai, Southeast coastline of Taiwan, also known as A-Lan-Yi Trail, which preserving the ecological environment and biodiversity with abundant geological activity record. Furthermore, to map the distribution of regional structures with topography in this accessible area, I applied the 5m DTM (Digital Terrian Model) to mark the bedding attitudes with GPS data, then I adopted the true 3D model based on unmanned aerial vehicle-derived images to observe the inaccessible high area. Afterword, I use FaultKin to calculate the striation data for paleo-stress direction and divide it to different stages by the crosscutting relationship then compare the result with former studies. This study provides a strong evidence of back-thrusting and back-folding deformation during the incipient oblique collision stage, and as well as the discovered structures in this area show the similar kinematic history as the eastern flank of Central Range. Finally, after concluding the paleo-stress stages to above-mentioned results, I propose a possible evolution model with deformation history of this study area.