Bulletin of the Geological Society of Malaysia, Volume 72, November 2021, pp. 1 – 13

Zircon U-Pb ages of the Benom Complex: Implications for a Late Triassic uplift event in Central Peninsular Malaysia

Choong Chee Meng^1,*, Manuel Pubellier², Benjamin Sautter¹, Mirza Arshad Beg¹

1 Universiti Teknologi PETRONAS, Geosciences Department, Seri Iskandar, 32610, Perak, Malaysia
2 Ecole Normale Superieure, PSL Research University, CNRS UMR 8538, Laboratoire de Géologie, France
* Corresponding author email address: choong.meng@utp.edu.my

Abstract: The Benom Complex, located in the Central Belt of Peninsular Malaysia, has recorded the dynamics of the orogeny with multiple igneous intrusions emplaced during the late tectono-magmatic stages of the Paleo-Tethys closure. Three new zircon U-Pb ages of igneous rocks from the Benom Complex reveal the crystallization of diorite and syenite (alkaline series) at 221.8±2.4 Ma and 226.6±3.5 Ma respectively, and granite (calc-alkaline series) at 207.2±2.0 Ma. The sedimentation of the Central Belt shifted from a marine to a terrestrial environment at the Middle-Late Triassic boundary, which marked the beginning of uplift due to the Sibumasu-Indochina collision. The emplacement of alkaline series of Benom Complex during the early Late Triassic (226.6 Ma to 221.8 Ma) are interpreted as related to a slab break off and mantle upwelling. Most of the Central Belt region has no records of sedimentation since the mid Late Triassic due to continuous uplift and/or erosion. The subsequent emplacement of the Gunung Benom granite (calc-alkaline series) took place at the end of the Triassic (207.2 Ma). The red bed deposition and the emplacement of the Benom Complex (together with S-type Main Range granite) result from a continuous Late Triassic orogenic uplift event in Peninsular Malaysia.

Keywords: Benom Complex, Central Belt, uplift, zircon U-Pb

DOI: https://doi.org/10.7186/bgsm72202101