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| Titel |
The Cretaceous and Cenozoic tectonic evolution of Southeast Asia |
| VerfasserIn |
S. Zahirovic, M. Seton, R. D. Müller |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1869-9510
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| Digitales Dokument |
URL |
| Erschienen |
In: Solid Earth ; 5, no. 1 ; Nr. 5, no. 1 (2014-04-29), S.227-273 |
| Datensatznummer |
250115267
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| Publikation (Nr.) |
 copernicus.org/se-5-227-2014.pdf |
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| Zusammenfassung |
Tectonic reconstructions of Southeast Asia have given rise to numerous
controversies that include the accretionary history of Sundaland and the
enigmatic tectonic origin of the proto-South China Sea. We assimilate a
diversity of geological and geophysical observations into a new regional
plate model, coupled to a global model, to address these debates. Our
approach takes into account terrane suturing and accretion histories, the
location of subducted slabs imaged in mantle tomography in order to constrain
the evolution of regional subduction zones, as well as plausible absolute and
relative plate velocities and tectonic driving mechanisms. We propose a
scenario of rifting from northern Gondwana in the latest Jurassic, driven by
northward slab pull from north-dipping subduction of Tethyan crust beneath
Eurasia, to detach East Java, Mangkalihat, southeast Borneo and West Sulawesi
blocks that collided with a Tethyan intra-oceanic subduction zone in the mid-Cretaceous
and subsequently accreted to the Sunda margin (i.e., southwest
Borneo core) in the Late Cretaceous. In accounting for the evolution of plate
boundaries, we propose that the Philippine Sea plate originated on the
periphery of Tethyan crust forming this northward conveyor. We implement a
revised model for the Tethyan intra-oceanic subduction zones to reconcile
convergence rates, changes in volcanism and the obduction of ophiolites. In
our model the northward margin of Greater India collides with the
Kohistan–Ladakh intra-oceanic arc at ∼53 Ma, followed by
continent–continent collision closing the Shyok and Indus–Tsangpo suture
zones between ∼42 and 34 Ma.
We also account for the back-arc opening of the proto-South China Sea from
∼65 Ma, consistent with extension along east Asia and the formation
of supra-subduction zone ophiolites presently found on the island of Mindoro.
The related rifting likely detached the Semitau continental fragment from
South China, which accreted to northern Borneo in the mid-Eocene, to account
for the Sarawak Orogeny. Rifting then re-initiated along southeast China by
37 Ma to open the South China Sea, resulting in the complete consumption of
proto-South China Sea by ∼17 Ma when the collision of the Dangerous
Grounds and northern Palawan blocks with northern Borneo choked the
subduction zone to result in the Sabah Orogeny and the obduction of
ophiolites in Palawan and Mindoro. We conclude that the counterclockwise
rotation of Borneo was accommodated by oroclinal bending consistent with
paleomagnetic constraints, the curved lithospheric lineaments observed in
gravity anomalies of the Java Sea and the curvature of the Cretaceous Natuna
paleo-subduction zone. We complete our model by constructing a time-dependent
network of topological plate boundaries and gridded paleo-ages of oceanic
basins, allowing us to compare our plate model evolution to seismic
tomography. In particular, slabs observed at depths shallower than
∼1000 km beneath northern Borneo and the South China Sea are likely to
be remnants of the proto-South China Sea basin. |
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