Dating Tectonism in the Indosinian–Thai–Malayan Orogen by Thermoluminescence

• Main Author: Hutchison, C.S.
• Format: Article
• Published: Geological Society of America 1968
• Subjects: Q Science (General); QE Geology
• Online Access: http://eprints.um.edu.my/25598/; https://doi.org/10.1130/0016-7606(1968)79[375:DTITIO]2.0.CO;2
• Institution: Universiti Malaya

The thermoluminescence "ages" of a large and representative selection of limestone specimens from the Thai-Malayan geosyncline, ranging in stratigraphic age from Ordovician to Triassic, are related, not to stratigraphic age, but to tectonic and magmatic events in the Mesozoic Indosinian-Thai-Malayan orogeny. It is deduced that the revolutionary phase of the orogeny extended from early Triassic to early Cretaceous; folding of the geosynclinal sediments and accompanying recrystallization of the limestones terminated in late Jurassic, but granitic activity extended to early Cretaceous. A post-orogenic phase of granitic intrusion, accompanied by secondary calcite veining of the limestones, occurred in early Tertiary and appears to be confined to a narrow zone along the western margins of the Main Range batholith. The thermoluminescence "ages" indicate that the revolutionary phase of the orogeny extended over a period of approximately 150 million years, which is in agreement with the radiometric ages of Malayan orogenic granites. © 1968, The Geological Society of America, Inc.