Bulletin of the Geological Society of Malaysia, Volume 73, May 2022, pp. 91 - 103

Clay minerals and their implications for Late Quaternary palaeoclimate investigation: A case study in Pontian, Johor

Abdul Hadi Hashim^1,*, Habibah Jamil¹, Ramlan Omar²

1 Geology Programme, Faculty of Science and Technology, 43600 Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
2 School of Environment and Natural Resource Sciences, Faculty of Science and Technology, 43600 Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
* Corresponding author email address: a.hadi.hashim@gmail.com

Abstract: Paleoclimate during Quaternary can be inferred from clay minerals composition in the coastal deposit acquired from the west coast of Johor, wherein this particular region has been linked with the few scholarly efforts delineating the field. This present study examined several core materials sourced from Pontian, Johor, mainly due to their almost entirely fine-grained sedimentary sequence suitable for high-resolution clay mineral assessment. Accordingly, semi-quantitative clay minerals assemblages were obtained by employing a series of measurement repetitions of air-drying, glycolation, and heating up to 350 °C and 550 °C on the sample conditions via X-ray diffraction (XRD) method. These assemblages were found to be predominantly kaolinite and illite in nature, apart from the presence of minor chlorite and smectite possibly sourced from the tuffaceous deep water deposit and granitic intrusive rock in central Johor. In line with this, stratigraphic clay mineral records revealed that the Late Quaternary experienced climatic changes between warm and humid conditions, whereas drier conditions were correlated to Greenlandian and Northgrippian sub-epoch of Holocene.

Keywords: Clay minerals, Holocene, paleoclimate, Quaternary, stratigraphy

Abstrak: Iklim kuno Kuaterner boleh dikenalpasti melalui komposisi mineral lempung yang didapati dalam enapan pesisir pantai barat Johor, di mana bidang ini kurang diketengahkan secara akademik di rantau ini. Kajian ini melibatkan teras gerudi dari Pontian, Johor yang hampir keseluruhannya berbutiran halus di mana cirian ini amat sesuai untuk penilaian mineral lempung beresolusi tinggi. Himpunan mineral lempung separa kuantitatif telah diperoleh melalui teknik pembelauan sinar-X. Sampel-sampel berkenaan diukur secara ulangan dengan syarat tertentu iaitu keringan udara, pengglikolan, pemanasan sehingga 350 °C dan 550 °C. Himpunan-himpunan lempung berkenaan didominasi oleh kaolinit dan illit serta sedikit komponen klorit dan smektit berkemungkinan berasal dari enapan laut dalam bertuf dan batuan granit terobosan dalam di kawasan pertengahan Johor. Maka, rekod stratigrafi mineral lempung ini menunjukkan perubahan iklim panas dan lembap kepada iklim yang lebih kering di Kuaterner Akhir. Ini boleh dikorelasikan kepada epok Greenlandian dan Northgrippian dalam Holosen.

Kata kunci: Mineral lempung, Holosen, iklim kuno, Kuaterner, stratigrafi

DOI: https://doi.org/10.7186/bgsm73202208

0126-6187; 2637-109X / Published by the Geological Society of Malaysia.
© 2022 by the Author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC-BY) License 4.0.