The Postglacial Marine Environment of the Northern Kaohsiung Coastal Plain－its implications for slip rate of the frontal fold-and-thrust belt

• Main Authors: Chih-Hao Chen, 陳志壕
• Other Authors: 陳文山
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/36670733547883597516

碩士 === 國立臺灣大學 === 地質科學研究所 === 97 === 　　The northern part of the Kaohsiung coastal-plain is an ongoing fold-and-thrust belt in the frontal orogenic belt. Previous studies concerning gravity and seismic profiles has shown that the structural framework in the study area is controlled by several NE trending thrust faults and folds, namely the Panpingshan anticline, Yuchang fault, Hsiaokangshan fault, Kangshan syncline, Chungchou anticline, Chungchou fault and Tawan syncline from east to west. The study aera can be divided into four tectonic domains by the Chungchou fault and the Hsiaokangshan fault ,including the coastal plain (Tawan syncline), the Chungchou tableland (Chungchou anticline), the Kangshan lowland (Kangshan syncline) and the western Foothills from west to east. 　　Based on the structural characteristics of the frontal fold-and-thrust belt, the borehole logging drilled by Central Geological Survey was rechecked in order to estimate the deformation rate through analysis of paleo-depositional environment, sequence stratigraphy, and radiocarbon dating. The result shows that subsidence rate of the Tawan syncline is -4.3±0.7 mm/yr, uplift rate of the Chungchou anticline is 3.0±0.9 mm/yr in axis and -0.2±0.9 mm/yr in limb, subsidence rate of the Kangshan syncline is -3.5±0.6 mm/yr, and uplift rate of the western Foothills is 1.5±0.9 mm/yr. The fault-propagation folding is proposed for which the Chungchou fault propagated and caused forming of the Chungchou anticline, and resulted into the Chungchou tableland. Hsiaokangshan fault deformed the overlying Holocene deposits but doesn’t cut the latter through. In addition, the Hsiaokangshan fault can be divided into two segments for different uplift rates, the northern segment has the vertical slip rate more than 3.2±1.6 mm/yr and its net slip rate probably more than 4.0±2.3 mm/yr, while the southern segment has the vertical slip rate less than 5.0±1.5 mm/yr and its net slip rate probably less than 6.1±2.4 mm/yr.