Stratigraphy, sedimentology and provenance of Mesozoic-Cenozoic sedimentary rocks, Sarawak, Malaysia

Personnel: Tim Breitfeld & Robert Hall

Themes: Sedimentology and provenance

Aims

This project investigates terrestrial to marginal marine sandstones from the Kuching Zone in Sarawak to determine their provenance and improve our understanding of the Cretaceous-Cenozoic evolution of eastern Sundaland. The main objective of this project is to investigate the Late Cretaceous to Cenozoic Kayan and Ketungau Basin Sequences. Mesozoic sediments and metasediments of the Sadong and Pedawan Formations which lie beneath the Kayan Sequence have also been analysed. Dating of igneous rocks and “basement” schists, combined with data from the Belaga Formation of the Sibu Zone, obtained from the recently completed SEARG MRes project by Thomson Galin, will help to improve the understanding of the tectonic evolution of Sarawak and Borneo and to reconstruct basin development in NW Borneo.

Background

The geology of Sarawak is divided into the Kuching Zone, the Sibu Zone and the Miri Zone. The Lupar Line separates the Kuching Zone from the Sibu Zone and may represent an important strike-slip fault. The sandstone formations are poorly dated because of their predominantly terrestrial character and lack of fossils. The sandstones are assumed to have been deposited between the Late Cretaceous and Late Eocene. There have been no previous provenance studies in the area. Igneous rocks were previously dated by K-Ar which could yield unreliable results. The metamorphic “basement” schists were undated prior to this project.

Recent Papers –

Max Webb et al., 2023. Mesozoic Magmatism of Natuna Island, Indonesia: Implications for the subduction history of eastern Indonesia. Gondwana Research

https://doi.org/10.1016/j.gr.2023.02.022

Breitfeld et al., 2022. Provenance of Oligocene-Miocene sedimentary rocks in the Cuu Long and Nam Con Son basins, Vietnam, and the early history of the Mekong River. International Journal of Earth Sciences.

https://doi.org/10.1007/s00531-022-02214-0

Nugraha et al., 2023. Plio-Pleistocene sedimentation and palaeogeographic reconstruction in the Poso Depression, Central Sulawesi, Indonesia: from a sea channel to a land bridge. Journal of Palaeogeography.

https://doi.org/10.1016/j.jop.2023.05.003

Recent News –

Amy Gough, Max Webb, and PhD Student Sam Holmes have recently returned from field seasons in SE Asia. All of them spent some time collecting river sediments on the Citarum River to look at how hydroelectric dams change heavy mineral assemblages. Max then headed off to Papua to look at how uplift of the Cyclops Mountains led to isolation of endemic species.

We’re on the move! Amy Gough has been offered a position at Heriot-Watt University as an Assistant Professor in Geoscience. Heriot-Watt has excellent ties with SE Asia, including a linked campus in Malaysia.

Amy Gough and Max Webb presented their current SEARG research at the SEAPEX Golden Jubilee in Singapore