Sedimentological and stratigraphical analysis of Kaki Bukit Formation (Lower Setul Member) at Teluk Ewa, Pulau Langkawi


Author : Mohamad Ezanie Abu Samah, Che Aziz Ali, Kamal Roslan MohamedPublication : Bulletin of the Geological Society of MalaysiaNumber : 72Page : 25 - 35Year : 2021DOI : doi.org/10.7186/bgsm72202103


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Bulletin of the Geological Society of Malaysia, Volume 72, November 2021, pp. 25 - 35

Analisis sedimentologi dan stratigrafi jujukan Formasi Kaki Bukit (Ahli Batu Kapur Setul Bawah) di Teluk Ewa, Pulau Langkawi

Sedimentological and stratigraphical analysis of Kaki Bukit Formation (Lower Setul Member) at Teluk Ewa, Pulau Langkawi

Mohamad Ezanie Abu Samah*, Che Aziz Ali, Kamal Roslan Mohamed

Program Geologi, Fakulti Sains dan Teknologi, Universiti Kebangsaan Malaysia, 43600, UKM Bangi, Selangor, Malaysia
* Corresponding author email address : mohamadezanie@yahoo.com

Abstrak: Penemuan beberapa unit baharu pada jujukan karbonat di kawasan Teluk Ewa (dari Tg. Mendidih hingga Teluk Ewa) telah mencetuskan idea untuk penyemakan semula stratigrafi Formasi Kaki Bukit (Ahli Setul Bawah). Aspek kajian merangkumi kajian sedimentologi, di mana jujukan sedimen membentuk sistem percampuran sedimen laut cetek yang menggabungkan perselangan di antara unit karbonat dan silisiklastik. Sebanyak lapan fasies sedimen ditemui antaranya (1) Fasies argilit, (2) Fasies selang lapis nipis batu lumpur dan batu kapur, (3) Fasies batu kapur stromatolit beralun, (4) Fasies batu kapur stromatolit lurus, (5) Fasies heterolitik batu lumpur-batu kapur, (6) Fasies syal, (7) Fasies batu kapur masif dan (8) Fasies batu kapur thrombolit. Setiap fasies dibahagikan kepada empat unit litostratigrafi berbeza berdasarkan kepada rujukan Jawatankuasa Penamaan Stratigrafi Malaysia (1997) dan Kod Stratigrafi Amerika Utara 2005. (1) Unit klastik yang merujuk bahagian paling atas Formasi Machinchang masih dikekalkan dengan penamaan lama. Manakala, penamaan baru yang dicadangkan adalah seperti (2) Ahli Sabung yang merujuk kepada bahagian dasar unit batuan karbonat terdiri daripada fasies mikrobial dan fasies percampuran sedimen klastik-karbonat. (3) Ahli Pesak Seluar di bahagian tengah iaitu unit batuan silisiklastik yang terdiri daripada fasies syal dan (4) Ahli Ewa di bahagian paling atas yang mewakili unit karbonat atas. Unit-unit batuan ini ditafsirkan mempunyai persamaan litostratigrafi dengan Kumpulan Tarutao Formasi Pante Malaka, Formasi Rung Nok dan Formasi Lae Tong di Thailand seperti yang dicadangkan oleh Wongwanich et al. (1990, 2002) dan Imsamut & Abdul Rahman (2017).

Kata kunci: Ahli Setul Bawah, Formasi Kaki Bukit, litofasies, unit stratigrafi

Abstract: The identification of new units on the carbonate sequence of Teluk Ewa (from Tg. Mendidih to Teluk Ewa) has given an idea for the review of stratigraphic succession of Kaki Bukit Formation (Lower Setul Member). The analysis is related to a sedimentology study, where the sedimentary sequences formed as a mixed siliciclastic–carbonate shallow marine system that combines the carbonate and silisiclastic deposits. Eight facies have been recognised such as (1) argillite facies, (2) interlayer of mudstone and limestone facies, (3) wavy stromatolites limestone facies, (4) linear stromatolites limestone facies, (5) heterolithic of mudstone-limestone facies, (6) shale facies, (7) massive limestone facies and (8) thrombolites limestone facies. Each facies are divided into four litostratigraphic units based on the evaluation from Malaysian Stratigraphic Nomenclature Committee (1997) and North American Stratigraphic Code 2005. (1) The clastic unit referring to the uppertmost part of Machinchang Formation maintains it's name. Meanwhile, the suggested nomenclature for the new units such as (2) The Sabung Member is referring to the basal carbonate unit comprising microbial facies and mixed silisiclastic-carbonate sediment. (3) The Pesak Seluar Member in the middle is a silisiclastic unit that consists of shale facies and (4) The Ewa Member at the top representing the upper limestone unit. All units show a similar litostratigraphic characteristics that are found in Tarutao Group, Pante Malaka Formation, Rung Nok Formation and Lae Tong Formation in Thailand as described by Wongwanich et al. (1990; 2002) and Imsamut & Abdul Rahman (2017).

Keywords: Lithofacies, Kaki Bukit Formation, Lower Setul Member, stratigraphic unit

DOI: https://doi.org/10.7186/bgsm72202103