The metamorphic Yuli Belt in Taiwan – Key to the tectonics of arc-continent collision and high-pressure rock exhumation

吕宋岛火山弧与中国被动大陆边缘碰撞形成台湾造山带。沿着欧亚板块（西）和菲律宾海板块（东）之间的碰撞缝合线，台湾最高级的变质单元暴露出来：玉里带，包括蓝片岩和蛇纹岩的变沉积物和透镜体。通过对玉里断裂带各剖面褶皱和剪切带的构造研究、对寿丰断裂带剪切岩的显微构造研究和结构测角学研究、对玉里断裂带的构造演化研究、对玉里断裂带的构造演化研究、对玉里断裂带的构造演化研究等，探讨玉里断裂带的构造演化史，特别是古地理起源、俯冲和折返过程。使用微XRF、拉曼光谱学、热压法和平衡相图计算来确定沿着这些横截面的变质条件;岩浆岩锆石U-Pb定年和变质沉积物中碎屑锆石定年;蓝片岩Lu-Hf定年。我们将测试的假说，即折返的玉里带有关的弧前提取。

The collision of the Luzon volcanic arc with the Chinese passive continental margin caused the formation of the Taiwan orogen. Along the collision suture between the Eurasian Plate (west) and the Philippine Sea Plate (east), the highest-grade metamorphic unit of Taiwan is exposed: the Yuli Belt, comprising metasediments and lenses of blueschist and serpentinite. We will investigate the tectonic history of the Yuli Belt, in particular, its palaeogeographic origin as well as its subduction and exhumation, using the following methods: structural study of folds and shear zones in sections across the Yuli Belt; microstructural studies and texture goniometry of sheared rocks from the Shoufeng Fault; determining metamorphic conditions along these cross sections using micro-XRF, Raman spectroscopy, thermobarometry and equilibrium phase diagram calculations; U-Pb zircon dating of magmatic rocks and detrital zircon populations in metasediments; Lu-Hf dating of blueschists. We will test the hypothesis that the exhumation of the Yuli Belt was related to forearc extraction.