From Basin Openings to Arc Accretion: An Alternative Model to Extrusion Tectonics and Implications to Resources Assessment in SE Asia

M. Aurelio¹ and M. Pubellier²

¹National Institute of Geological Sciences, UP Diliman, Q.C.
²Ecole Normale Supérieure de Paris, France

Abstract

Since the 1980’s, many tectonic features in the (SE) Asian region have been interpreted to be the result of extrusion tectonics which involved the collision of India with Eurasia at the beginning of the Cenozoic. For instance, this model considers crustal openings such as those that formed the South China Sea as the result of pull-apart systems generated along major strike-slip faults produced by extrusion. However, there is difficulty in using the extrusion mechanism to explain the presence of many other ocean basins in the region which present a wide range of ages and geographic distribution. Further, the complex distribution of arc systems in the region many of which are associated with nearby oceanic crustal pieces, calls for a more comprehensive mechanism of formation. An integrative review of a vast source of information especially from previously restricted material allows to establish a more robust model that accounts for the varied ages and complex distribution of marginal ocean crusts and arc systems in the (SE) Asian region. Understanding these complexities is crucial in assessing the resource potential of these tectonics features.