本年度計畫為全程三年研究的第三年，在三年中預計完成以下的項目： 1) 地下斷層演化與地表地形和次盆地發育的相關性：斷層的運動及地下構造型態及位置，影響盆地及第四紀地形的發育。研究沿著斷層走向位移型態(位移量及移位方向)的改變，伴隨的生長褶皺（包括背斜及向斜）在地層傾角及岩層繞著褶皺軸旋轉的角度變化，以及相關可以量化地形指標的變化。這些地形指標特徵包括：河階、水系密度、河階地沈積物的傾動、翼部傾角變化、集水盆地的不對稱性、河流波降指數、山脈前緣的蜿蜒度、河谷寬深比及面積高度積分等。 2) 地下構造方面：利用新的鑽井、震測剖面及地表構造資料，重新審視確立西南部地下構造的型態並建立沿活動構造走向一系列大比例尺、密集的剖面，以了解構造型態的改變與斷層的幾何型態、運動的方式及速率和活動性的關係。配合地表測量的地殼變動 (包括大地衛星及水準測) 資料，解釋地下斷層的幾何型態及移位速率。 3) 斷層的三維構造發育：研究解斷層之間相對的活動度、位移轉換、斷層分段的幾何構造及可能的發震構造位置；特別針對構造及斷層的形貌和褶皺機制在側向方向上的型態及位移量變化。在第一年中我們完成重新審視及解釋台南關子嶺一帶的下構造，以及曾文溪流域地形計測指標與構造發育之關係。第二年研究地形指標與地表地殼形變的資料 (包括短期GPS測量及中長期影像判釋) 。第三年結合GPS觀測、地形指標配合地下斷層及褶皺的構造，瞭解地表地形與地下構造發育之間的量化關係，進一步探討區域性地表地形及地下構造的演化模式。 ; This project is the third year of three-year program. We propose to study three-dimensional subsurface structure and active surface geomorphology in the Fold-and-Thrust belt of southwestern Taiwan in three years through the following analyses: A. Development of surface topography with evolution of subsurface fault: investigate both structural and geomorphologic changes associated with lateral development of active structures. Geomorphic indices, such as river terraces, river channel density, drainage basin asymmetry, hypsometric integral, S-L index and mountain-front sinuosity that are sensitive to active tectonics will be quantified to correlate the growth of subsurface structure. B. Subsurface Structure: use oil wells and acquired seismic profiles, and surface data to re-interpret the complex subsurface structure of southwestern Taiwan. Construct a series of cross sections to characterize the subsurface fault model and correlate the surface displacement rates from GPS geodetic survey. The ultimate goal is to establish an integrated model of crustal movement with subsurface structure growth through modeling. C. Three-dimensional evolution of active structure model: Study lateral development of individual faults and linkage between faults to characterize possible displacement transfer, linkage (or fault-segment) structure and partitioned of displacement among faults. We have reviewed and reinterpreted the subsurface structure of the Kuanzulin Anticline and Chaochou fault and surveyed terrace deposits along the Tsennwen River in the first year. A continuing survey of morphometric indices and its quantitative relationship with both GPS and satellite images derived surface deformation rate are the focus of the second year research. In the last year, we will combine all above data and validate our cross sections to understand regional evolution of active geomorphology and subsurface structures. ; 研究期間 9808 ~ 9907
