Cenozoic SE Asia Sedimentary Basins Evolution: Using Gplates Software to Correlate with Plate Tectonics in this Region

Abstract:

Most of the sedimentary basins around SE Asia were formed during Late Cretaceous to present. Previous studies suggested that Sundaland is a stable core in SE Asia that experienced the interaction of 4 major plates (Eurasia, India, Pacific and Australia plates). Although the plate tectonic history is very complicated, most of the sedimentary basins developed under the extensional regime. In Cenozoic, there are at least two contractional and four extensional events can be identified in this regime. The first contractional event is India plate colliding with Eurasia in Early Eocene, which propagated to the northern part of Sundaland and made Indochina block escape southeastward into the present-day South China Sea. The second one was in Early Miocene where Australia plate, along with many micro-continental blocks, drifted northward and collided with Sundaland that generated inversions in SE Sundaland. On the other hands, four marginal basins have their sea-floor spreading in Cenozoic, namely South China Sea (30-16Ma), Sulu Sea (17-12Ma), Celebes Sea (49-35Ma) and Andaman Sea (20-5Ma), that caused the sedimentary facies in the basins changing from mainly terrigenous to partially marine. In order to understand the evolutionary history of sedimentary basins and their relationship with plate tectonics, we used Gplates program to reconstruct SE Asia from Late Mesozoic to present. About 25 isopaches of major sedimentary basins were compiled into the program. So far, we can conclude that the key rifting event of the sedimentary basins were stared from Early Eocene that could be correlated with the India-Eurasia collision.