Bulletin of the Geological Society of Malaysia, Volume 51, June 2005, pp. 77 – 82

Sedimentological and palaeontological study along the Kuala Tekai-Kuala Tahan stretch of Tembeling River, Jerantut Pahang

Ainul Rubizah Ariffin, Sharifah Shahira Wafa Syed Khairulmunir Wafa, Saiful Abdullah and Uyop Said

Geology Programme, School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia

Abstract: The rock succession which is exposed along the riverbank from Kuala Tekai to Kuala Tahan of Tembeling River was mapped and interpreted by previous workers as part of the Semantan Formation. However, detailed sedimentological and palaeontological study which was carried out during this study distinguished the succession into the Semantan Formation and the Mangkin Sandstone Formation of the Tembeling Group. The Semantan Formation consists of three major sedimentary facies, namely; laminated siltstone interbedded with shale facies, laminated carbonaceous shale facies, and graded bedding sandstone facies. Four major sedimentary facies were identified in the rock succession of the Mangkin Sandstone Formation. These are pebbly sandstone interbedded with sandstone facies, massive sandstone facies, interbedded sandstone and siltsone facies and interbedded sandstone and mudstone facies. The discovery of fairly well-preserved palynomorphs in the studied rock succession can be utilised in interpreting the age of the rocks. Some twenty palynomorph taxa were identified which include Retitriletes circolumenus, Lycopodiumsporites sp., Lycopodiumsporites eminulus, Klukisporites variegatus, Neoraistrickia truncates and Cyathidites punctatus. The identified palynomorph assemblage is comparable to Stylosus Assemblage of Neocomian-Aptian age.

Abstrak: Jujukan batuan yang tersingkap di sepanjang tebing Sungai Tembeling dari Kuala Tekai ke Kuala Tahan telah dipetakan dan ditafsirkan oleh pengkaji terdahulu sebagai Formasi Semantan. Walau bagaimana pun, kajian sedimentologi dan paleontologi terperinci yang dijalankan sekarang membahagikan jujukan batuan tersebut kepada Formasi Semantan dan Formasi Batu Pasir Mangkin dari Kumpulan Tembeling. Formasi Semantan terdiri daripada tiga fasies sedimen yang utama iaitu fasies selang lapis batu lodak berlaminasi dengan syal, fasies syal berkarbon berlaminasi dan fasies batu pasir berperlapisan berperingkat. Empat fasies sedimen yang utama telah dikenal pasti dalam jujukan batuan Formasi Batu Pasir Mangkin. Fasies sedimen tersebut ialah fasies selang lapis batu pasir berpebel dan batu pasir, fasies batu pasir masif, fasies selang lapis batu pasir dan batu lodak dan fasies selang lapis batu pasir dan batu lumpur. Penemuan palinomorf yang terawet sederhana baik dalam batuan yang dikaji boleh digunakan dalam membuat tafsiran usia batuan tersebut. Lebih kurang dua puluh taksa palinomorf telah dikenal pasti termasuklah Retitriletes circolumenus, Lycopodiumsporites sp., Lycopodiumsporites eminulus, Klukisporites variegatus, Neoraistrickia truncates dan Cyathidites punctatus. Himpunan palinomorf yang dikenal pasti mempunyai persamaan dengan Himpunan Stylosus yang berusia Neocomian-Aptian.

https://doi.org/10.7186/bgsm51200510