Tertiary basins of S.E. Asia-their disparate tectonic origins and eustatic stratigraphical similarities


Author : Charles S. HutchisonPublication : Bulletin of the Geological Society of MalaysiaVolume : 19Page : 109 – 122Year : 1986


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Bulletin of the Geological Society of Malaysia, Volume 19, April 1986, pp. 109 – 122

 

Tertiary basins of S.E. Asia-their disparate tectonic origins and eustatic stratigraphical similarities

CHARLES S. HUTCHISON

Dept. of Geology, University of Malaya, Kuala Lumpur

 

Abstract: Following the Indosinian Earliest Jurassic compressive orogeny, Tertiary basins of Southeast Asia developed during the Late Mesozoic and Early Cenozoic by extensional tectonics combined with wrench fault control. The major basin-forming mechanisms are: rifting of Atlantic-type miogeoclinal margins, aulacogens; fore-arc, intra-arc, and various back arc extensions. Tertiary compressive movements were important only in some basins such as those lying between India and Burma, between the South China Sea microcontinents and Borneo, and between Australia and the Banda arc. Elsewhere throughout most of the region, those collisions were transmitted as major basement wrench movements which resulted in non-compressive open cover folds on the Tertiary basin fill.

With the exception of marginal seas, sedimentation kept pace with basin dilation and subsidence, and in the absence of compressive orogenic events which might cause uplift, basin unconformities, regressions and transgressions are related to global sea level changes. The eustatic rise from 29 Ma to 13 Ma ago is evident as a widespread Mid Miocene transgression over basins which had developed earlier on continental crust. Sea level drops at 13, 9.8 and 6.6 Ma ago are well documented as widespread regressions in Indonesian and Malaysian basins.

The excellent correlation of eustatic sea levels with transgressions and regressions in S.E. Asia maybe an artifact of overdependence upon S.E. Asian basins during the compilation of the eustatic curves.

https://doi.org/10.7186/bgsm19198610