台灣與呂宋島間的馬尼拉隱沒帶是過去較少被研究到的區域，其地體構造不但有其複雜性且牽涉到台灣島的形成因果關係。南海的岩石圈沿著馬尼拉海溝由西向東隱沒到花東海盆(菲律賓海板塊)下方，並形成呂宋島弧。呂宋島弧形成的時間正好早於台灣島造山運動的開始，以其增積岩體來說，地形上由南而北逐漸變寬，以呂宋火山島弧而言，則由北而南逐漸變寬，甚至在南段有雙島弧的形成。值的注意的是馬尼拉隱帶沒有弧後盆地的伴隨存在，但更東邊則有南北走向加瓜海脊為界，分隔西菲律賓海盆，此間的地殼構造愈靠近呂宋島因為過去研究較少愈不清楚，因此藉此台菲地球科學合作的機會。子計畫一預期以三年的時間研究整個馬尼拉隱沒帶的地殼構造和特性，尤其著重在靠近呂宋島的馬尼拉海溝附近及加瓜海脊南端部份的地殼構造。蒐集研究區域的海洋地球物理資料(含震測、重力、磁力和水深等資料)，此為第三年計劃，持續蒐集和分析解釋台灣及菲律賓的隱沒帶海洋地球物理資料，今年預定利用美國研究船Marcus Langseth (TAIGER計畫延伸)在台灣及菲律賓間的馬尼拉隱沒帶及西菲律賓海盆的西北部作廣角的地殼深部反射震測研究，並綜合其它相關資料作整體地體構造解釋。 ; The tectonics of the reagion between Taiwan and Luzon islands was seldom studied in the literature. This region involving the formation of the Luzon Arc and the related formation of the Taiwan orogeny is complicated in terms of geodynamics. The South China Sea lithosphere has subducted eastward beneath the Huatung Basin (Philippine Sea Plate) along the Manila trench and has formed the Luzon Arc. The Luzon Arc has formed prior to its collision with SE Eurasian margin and has created the Taiwan orogen. Morphologically, the accretionary prism of the Manila subduction zone has widened northward while the Luzon Arc has widened southward. The Luzon Arc has even double zones in the southern portion. It is worthy of noting that the Manila subduction does not accompany the formation of a back-arc basin. Further east, it is bounded by the Gagua Ridge. The tectonics as well as the crustal structures of the southern Manila subduction zone was rarely understood. Hence, under the Earth Science cooperation between Taiwan and the RP scientists, we would like to propose a three-year project focusing on the southern part of the Manila subduction zone the southern part of the Gagua Ridge. We will conduct related marine geophysical cruises and provide tectonic interpretation of the study area. This is the third year of the project. This year we will use US R/V Marcus Langseth to do Multichannel Channel Seismic(MCS) reflection in the area across Manila subduction zone and the NW portion of the West Philippine Basin. The result will help us understand the deep crustal structures of the area around Taiwan and Philippines. ; 研究期間 9808 ~ 9907
