Southeast Asia: New Views of the Geology of the Malay Archipelago

Abstract

Southeast (SE) Asia is surrounded by subduction zones causing intense seismicity and volcanic activity. Subduction has been the principal tectonic driver of collisions that caused the growth of continental SE Asia, and most recently the collision of Australia with SE Asia. The western part of SE Asia, Sundaland, is a heterogeneous and weak region, reflecting processes that can be observed today in the east, where there are subduction zones in different stages of development. A close relationship between subduction rollback and extension has caused dramatic elevation of land, exhumation of deep crust, and spectacular subsidence of basins, observable with remotely acquired images and seismic and multibeam data obtained from oil exploration. New dating indicates that subsidence and uplift occurred at high rates during short time intervals. Laboratory studies, modeling, and reconstructions provide valuable insights, but field-based studies continue to present surprises and new discoveries essential for interpretations of the geological history of the region.