摘要:本研究計畫「亞洲大地構造運動與環境變遷研究」將針對國際地球科學界若干重大的地質問題,包括:大陸地殼之增生與演化、青藏高原與喜馬拉雅山的隆起、東亞地區大地構造運動對環境變遷之衝擊等,以活躍於相關研究領域的台大地質系及中研院地科所既有人力組成研究團隊,透過多項國際合作的推動和世界級地球化學實驗室的建立,進行系統性的整合研究,探討亞洲地區大地構造演化對環境氣候變遷的影響,期待藉由本計畫之推行,使台大成為國際上研究相關地質問題首屈一指的重鎮。
本計畫包含三個密切關聯的子計畫,其主題分別為:
(1) 經由增積與碰撞造山作用探討亞洲大陸之增生與演化。
(2) 板塊運動對東亞區域的環境氣候所造成的衝擊。
(3) 在台大設立世界級的同位素地球化學實驗室。
Abstract: The immense size of the Asian continent readily indicates that it must be composite in nature, formed by amalgamation of plates and terranes over a long period of geological time. Analyses of paleomagnetic data and present plate motions appear to suggest that Asia is a "supercontinent" (= future Gondwana) in the making. We intend to study the evolution of the Asian continents (pl.) as well as ocean basins (both ancient and modern) through the entire Phanerozoic era. This project should emphasize the continental geology as this is where the real strength of the proponent group lies.
The proposed research project "Asian Orogenesis and Environmental Changes: A Multi-Disciplinary Approach" is aimed to tackle some of the most important geological problems, particularly, those concerning the growth, deformation history and tectonic evolution of Asia in the Phanerozoic era, and influence of tectonic uplift to the Cenozoic and recent environmental and climatic changes. The project assembles the currently most active and dynamic researchers at NTU and IES-Academia Sinica to work together. Their diverse disciplines will be coordinated to produce the most significant results. The project calls for a multi-disciplinary approach, including field and structural analyses, geochronological, petrological, geochemical and geophysical (particularly, paleomagnetic) studies. The field and structural analyses and geophysical study could only be achieved through cooperation with other specialists. Consequently, we emphasize the importance of international cooperation.
The present proposal comprises two seemingly unequal but tightly connected parts: the major part is composed of problem-oriented sub-projects and the minor part, but critical to all the others, is a technique-oriented project. The problem-oriented sub-projects represent a comparative and coherent study of accretionary and collisional orogens in East Asia, as well as the causal effect of the uplift of the Tibetan/Himalayan orogen on climatic change. The minor technique-oriented project would be focused on the development and enhancement of our analytical capabilities, particularly on state-of-the-art techniques of magnetic sector MC-ICPMS (Multi-Collector Inductively Coupled Plasma Mass Spectrometry). In summary, we present three interlocked sub-projects as follows:
(1) Growth and evolution of the Asian continent, as evidenced from contrasting orogens: accretionary (Central & East Asia, and Taiwan) and collisional (the Tibetan Plateau and Himalayas). In accretionary orogenic belts of Central and East Asia (e.g., the Altai and Xing`an Mountians in China), we intend to study an interesting style of orogeny in which abundant juvenile crust formed and the size of continent enlarged. This study is intimately connected to a new project of the International Lithosphere Program (ILP). In collisional orogenic belts, as represented by the Tibetan plateau and Himalayas, our goal is to study the processes of mountain building as well as thickening and recycling of the continental crust.
(2) Tectonic impacts on the environmental changes in East Asia. We will undertake some of most fashionable research topics and use the world-class geochemical facilities to be established at NTU. Our studies aim to understand the probable link between tectonic processes (mountain building) and paleoenvironmental/paleoclimatic changes, such as modification of atmospheric circulation or monsoon patterns, changes in the seawater composition, interactions between tectonic uplift, river erosion and alluvial deposition, provenance of loess deposits, as well as desertification in Central Asia.
(3) Establishment of a world-class laboratory of isotope geochemistry at the Department of Geosciences, National Taiwan University. This is very crucial to the success of the above research projects.