Parallel Tethyan sutures in mainland Southeast Asia: New insights for Palaeo-Tethys closure and implications for the Indosinian orogeny

Abstract

Two contrasting parallel tectonic sutures can be recognised through the Yunnan-Thailand region of mainland Southeast Asia; they are sutures of the Devonian-Triassic Palaeo-Tethys Ocean and a Permian back-arc basin. The Changning-Menglian and Inthanon suture zones are regarded as the Palaeo-Tethys Suture Zone. The Jinghong-Nan-Sra Kaeo suture is regarded as a closed back-arc basin. The Sukhothai Zone is no longer treated as a part of the Sibumasu Terrane, but is defined as the core part of the Permian island-arc system developed on the western margin of the Indochina Terrane. Two tectonic events are interpreted from the parallel sutures; a Late Permian collapse of the back-arc basin and a mid-Triassic collision of Sibumasu to the Sukhothai Arc of Indochina (= closure of the Palaeo-Tethys). The Early-early Middle Triassic thermotectonism of Vietnam as linked to the Indosinian orogeny by some authors is incompatible with the suggested timing of Sibumasu collision, but instead it is temporally closer to the back-arc compression of western Indochina. To cite this article: M.

Did Oligocene crustal thickening precede basin development in northern Thailand? A geochronological reassessment of Doi Inthanon and Doi Suthep

“…The late Triassic suturing of the Palaeo-Tethys leading to the Indosinian Orogeny (Metcalfe, 2000 andMetcalfe, 2008) was followed by the suturing of the Neo-Tethys, the collision of the Indian plate with Asia, and the onset of the Himalayan Orogeny at ca. 50 Ma (Green et al, 2008).…”

Where was the Ailaoshan Ocean and when did it open: A perspective based on detrital zircon U–Pb age and Hf isotope evidence

“…Previous studies suggested two Paleo-Tethyan branches in SE Asia, namely the Main Paleo-Tethys represented by the ChangningMenglian-Inthanon suture Kamata et al, 2012), and the Ailaoshan Ocean represented by the Jingshajiang-Ailaoshan suture (Sone and Metcalfe, 2008;Zaw et al, 2014). It has been commonly accepted that the Main Paleo-Tethys had opened in the Silurian-Devonian and closed in the Triassic by an east-directed (modern orientation) subduction beneath Indochina-Simao (Metcalfe, 2013;Zaw et al, 2014).…”

Higher-resolution biostratigraphy for the Kinta Limestone and an implication for continuous sedimentation in the Paleo-Tethys, Western Belt of Peninsular Malaysia

“…The closure of the Paleo-Tethys was in the Middle Triassic (Sone et al, 2008), implying that there was accommodation space for a continuous deposition of sedimentary successions in the paleo-basin. Moreover, the global sea level for the Phanerozoic (Haq and Schutter, 2008) was on the rise from the Devonian to lower Carboniferous.…”