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

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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.