PhD - The role of the SE China passive margin for the formation of Taiwan orogen

The project aims to investigate the control of structural, lithological and thermal inheritance of the former SE China margin during the formation of the Taiwan orogen. The structural setting of Taiwan represents a unique natural laboratory to study mountain building processes, since it results from the oblique collision of SE China rifted margin with the Luzon magmatic arc (Fig. 1). This unique setting of Taiwan enables the investigation from south to north of the gradual transition from passive margin subduction under an island arc to a continent-arc collision in Taiwan.

Expected results aims to provide new tectonic models of early collision, being one of the least understood and documented stage of orogeny.

Methodology

This project will be based on an offshore-onshore approach combining various geophysical surveys with field-related data sets. Offshore, we will use the dense geophysical TAIGER data set, including multichannel and wide-angle seismic data combined with additional seismic data available from the literature or owned by partner institutions. Seismic profiles will be interpreted in a workstation using the Petrelsoftware. First order interfaces in seismic sections will be consistently identified and mapped such as the seafloor, pre-, syn, post-rift, and pre-, syn, post-compression stratigraphic sequences as well as the top-basement. These results will be compared to additional geophysical data sets, including gravity and magnetic anomaly maps. Onshore, the remnants of the former SE China rifted margin imbricated in Central Taiwan will be investigated.

These observations will allow the establishment of maps (including structural and rift domain) associated with a series of geological cross-sections capturing the different stages of the inversion of the SE China margin. All together, these results aim to reveal the potential role of rift inheritance in localizing and controlling subsequent inversions in Taiwan.

Scientific environments

The PhD student will be based at CY Cergy Paris University in the Geoscience and Environment department. This project is proposed in the frame of the submission of a join France – Taiwan research program on the processes of collision in Taiwan. The PhD Candidate will therefore interact with Taiwanese researchers from the NTU and different French researchers from the University of Toulouse, University of Strasbourg, ENS Paris and Sorbonne University.

If interested and pending level in French, the PhD candidate will have the opportunity to teach to undergraduate students (64h per year).

Requirements

This project is based on a pluridisiplinary approach including tectonic, structural geology, marine geology, field geology. Solid experience in several of these disciplines is expected. The successful candidate has an MSc degree in geosciences. Knowledge of French is not mandatory but basic skills or willing to learn will be appreciated. Good knowledge of English is essential.

Contact

For application and more information, please contact Geoffroy Mohn (geoffroy.mohn@u-cergy.fr)