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

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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.