2015-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/670634摘要：地表的岩石圈主要可以由兩種方式回到深部的地函：海洋板塊的隱沒作用以及大陸岩石的拆沈作用。這兩種作用都發生在聚合板塊的邊界，在大陸造山系統上尤其複雜，岩石圈劇烈碰撞的過程牽涉到增厚再減薄，碰撞前又曾有隱沒的發生，現今殘存的板塊位置及大小等相關證據可以幫助我們了解是否有岩石圈斷裂或拆沈，並回溯碰撞歷史和條件。伊朗高原為阿拉伯板塊與歐亞大陸板塊碰撞所生成，造山背景類似西藏高原並且碰撞前同樣有新特提斯洋的隱沒，但是該區域的地函相關研究相對較少，目前以S波結果為主，並且解析度在深部地函明顯降低。本研究將利用台灣設於高加索區域的測站和土耳其地震站所形成的大型觀測網，分析來自興都庫什區域及巴基斯坦的地震，以多重波路徑法研究伊朗及鄰近地區地地函過渡帶之速度構造。期望本計畫能獲得科技部支持，以繼續維護高加索地震網，並加強跨國(喬治亞與、美尼亞及伊朗)、跨領域的合作，結果將可與地震波層析成像以及淺部岩石圈構造一起解釋，並與西藏結果相比對。<br> Abstract: There are two main mechanisms to recycle tectonic plates into deep mantle: subduction of oceanic slab and delamination of sub-continental lithosphere. Both of them occur in convergent boundaries to create mountains and plateaus. In particular, the orogenic belt caused by continental collision is a complicated process that involves thickening and thinning of deformed lithosphere, and closure of former subduction along the passive margin. The current configurations of plates near surface and remnants merged in the deep mantle can help us understand whether the break-off or delamination of lithosphere happened in the past. In other word, the resulting image depends on the history and conditions of continental collision. Iranian plateau is created by the collision between Arabian and Eurasian plates. The tectonic background is similar to Tibet and both cases involve the subduction of Neo-Tethys slab before the collision. The deep structure under Iran is still poorly constrained due to limited data. In this project, we propose to investigate the mantle transition zone under Iran and surrounding region with a large array combing stations in the Turkey and those in Caucasus region from Taiwan. We will construct a fan of profiles and analyze triplication waveforms from the earthquakes in Hindu-Kush and Pakistan. With the support from MOST, we are able to maintain the seismic array in the Caucasus, collaborate with scientists from different international institutes and fields of discipline. The results from deep mantle can be jointly interpreted with studies of tomography and other geologic constraints at shallower depth. It can also further be compared to our previous work in Tibet.大陸碰撞伊朗西藏拆沉作用地函過渡帶地震波多重波路徑continental collisionIranTibetdelaminationmantle transition zoneseismic triplication