Cross section balancing across the Taiwan fold-and-thrust belt for improving palaeogeographic reconstructions of the Eurasian passive margin

我们打算通过在全岛三条横断面上构建新的平衡截面，更好地限制台湾褶皱冲断带的整体缩短量。这就需要收集更详细的岩性、片理方向和断裂带运动学方面的信息，特别是在前新生代基底暴露的地方。一方面，我们的目的是验证我们目前的工作假设，根据该假设，暴露在所谓的Tailuko和Yuli带的前新生代基底是由两个地壳尺度的叠瓦构成的，它们在碰撞后不久沿着w向逆冲接触并置。其次，我们打算验证在推覆体堆积之后，这两个构造单元是否参与了地壳尺度的反向褶皱，从而导致了第二次垂直至陡西倾的年轻理裂的发育，该理裂覆盖了与推覆体堆积相关的旧理裂。因此，我们对台湾中央山脉基底单元的进一步认识将为新的平衡剖面构造提供基础，从而使我们能够依靠冲断带缩短的定量估计，对弧-陆碰撞前的欧亚被动边缘进行新的古地理恢复。

We intend to better constrain the amount of overall shortening in the Taiwan fold-and-thrust belt by constructing new balanced cross sections along three transects across the island. This requires collecting more detailed information on the lithologies, the orientation of foliations and kinematics of fault zones encountered along the transects, particularly where pre-Cenozoic basement is exposed. For one thing, we aim at verifying our current working hypothesis, according to which the pre-Cenozoic basement exposed in the so-called Tailuko and Yuli belts is built up of two crustal-scale imbricates that were juxtaposed along a W-vergent thrust contact soon after collision. Secondly, we intend to verify whether, following nappe stacking, these two tectonic units became involved in crustal-scale back-folding, leading to the development of a second, vertical to steeply W-dipping younger cleavage that overprinted older nappe-stacking related foliations. Our improved understanding of the basement units in Taiwans Central Range will thus provide the base for new balanced cross section constructions, which, in turn, will allow us to make new palaeogeographic restorations of the Eurasian passive margin prior to arc-continent collision, relying on quantitative estimates of thrust belt shortening.