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

台湾褶皱逆冲带的剖面平衡改善欧亚被动边缘的古地理重建

基本信息

批准号：
380155214
负责人：
Professor Dr. Nikolaus Froitzheim
金额：
--
依托单位：
Arbeitsgruppe Strukturgeologie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2017
资助国家：
德国
起止时间：
2016-12-31 至 2020-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/380155214?language=en
关键词：
Cross section balancing across Taiwan

项目摘要

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.

我们打算通过沿着台湾岛的三个横断面建造新的平衡横截面，更好地限制台湾褶皱逆冲带的整体缩短量。这需要收集有关沿断面遇到的断层带的岩性、叶理方向和运动学的更详细信息，特别是在前新生代基底暴露的地方。一方面，我们的目标是验证我们当前的工作假设，根据该假设，所谓的太鲁科和玉里带中暴露的前新生代基底是由两个地壳规模的叠瓦岩组成，它们沿着W字形的逆冲接触并置碰撞后不久。其次，我们打算验证，在推覆堆积之后，这两个构造单元是否参与了地壳尺度的向后折叠，从而导致了第二个垂直于陡峭的西倾的年轻解理的发展，该解理覆盖了较旧的推覆堆积相关的叶理。因此，我们对台湾中央山脉基底单元的进一步了解将为新的平衡截面构造提供基础，这反过来又将使我们能够在弧大陆碰撞之前对欧亚被动边缘进行新的古地理恢复，依靠逆冲带缩短的定量估计。