- 1Laboratoire de Géologie, CNRS/UMR 8538, Ecole Normale Supérieure, PSL Research University, 24 Rue Lhomond, 75005 Paris Cedex, France (bulois@geologie.ens.fr)
- 2Géosciences Environnement Toulouse (GET), CNRS, Université Toulouse III-Paule Sabatier, IRD, CNES, OMP, Toulouse, France
- 3ISTeP, Sorbonne Université, Paris, France
Only limited orogens show preserved markers of collision initiation, so that this specific stage is generally not integrated in plate tectonic models attempting to reconstruct their evolution. In SE Asia, this is the case of the Philippine Mobile Belt in the Philippines and Taiwan, but basement elements involved in the growth of the belt are generally not integrated to fully comprehend the construction of the region.
The geological evolution of the Philippine-Taiwan region includes extensional, compressional and transform settings overlapping in space and time since the Late Cretaceous. The resulting tectonic blocks move along major reactivated and newly-formed fault systems shaping the conjugate Eurasia/Australia margins of the South China Sea and accommodating the oblique subduction of the Philippine Sea Plate below Eurasia. Large-scale kinematic models generally describe well the clockwise rotation of the Philippine Sea Plate that drives the regional compression obliquely to the plate boundary since the Eocene. However, the detailed origin, geometry and motion of internal tectonic blocks of the Philippine Mobile Belt are often hypothetical due to the lack of onshore and offshore geological correlations.
In the frame of the research project COLLISEA (ANR-22-CE49-0015), we have collected a comprehensive geological and geophysical dataset to map accurately pre-accretionary structures and to decipher how these elements were involved during the subduction-collision transition. Until 2 Myrs (Pleistocene), the tectonic motion is reconstructed using GPS data. Then, detailed geological mapping enables us to model further motions until at least 15-20 Myrs (Early Miocene). Doing so, we progressively unfold the Philippine Mobile Belt and propose palaeogeographic reconstructions of the various tectonic blocks through the last 20 Myrs. This enables to discuss the variations of velocity and deformation styles along the plate boundary and to give new insights on geological parameters involved in the collision initiation.
How to cite: Bulois, C., Pubellier, M., Mouthereau, F., Chamot-Rooke, N., Larvet, T., Labis, F. A., and Delescluse, M.: Temptative assessment of tectonic blocks affinities to reconstruct the Philippine-Taiwan region, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17173, https://doi.org/10.5194/egusphere-egu25-17173, 2025.
