Litho- and Biostratigraphic Correlations of Chert Beds in Various Rock Units Along the Malaysia-Thailand Border
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- 1 - LITHO- AND BIOSTRATIGRAPHIC CORRELATIONS OF CHERT BEDS IN VARIOUS ROCK UNITS ALONG THE MALAYSIA-THAILAND BORDER By: The Malaysian-Thai Working Group A joint project carried out by Minerals and Geoscience Department Malaysia And Department of Mineral Resources, Thailand The Malaysia-Thailand Border Joint Geological Survey Committee (MT-JGSC) 2012 PREFACE The study on the litho- and biostratigraphic correlations of chert beds in various rock units along the Malaysia-Thailand border area is the result of close co-operation between the Minerals and Geoscience Department Malaysia, and the Department of Mineral Resources, Thailand in resolving problems related to cross border geological and stratigraphical correlations between the two countries. Most of the data presented in this report are gathered from reports by previous workers who have made detailed studies on the radiolaria found in the cherts that occur in various rock units ranging in age from the Carboniferous to Triassic, cropping out along/near the border areas of Malaysia and Thailand. Several trips of fieldwork and collection of some new data were also carried out independently by geoscientists of the Minerals and Geoscience Department Malaysia, and the Department of Mineral Resources, Thailand covering the individual territories in the year 2011 and 2012. New data obtained from the joint survey carried out by the Malaysian and Thai Working Groups in the Belum-Hala Transect area are also included in this report. Problems on the litho- and biostratigraphic correlations between chert beds in various rocks units in both sides of the common border areas have been satisfactorily resolved. Other than that, with the implementation of this project, the objective of the establishment of the Malaysia- Thailand Border Joint Geological Survey Committee (MT-JGSC) to foster closer cooperation between both countries in the field of geosciences is successfully achieved. Dato’ Yunus bin Abdul Razak Mr. Nitat Poovatanakul Director-General, Director-General, Minerals and Geoscience Department, Department of Mineral Resources, Malaysia. Thailand. September 2012 September 2012 iii ACKNOWLEDGEMENTS The Malaysian-Thai Working Group would like to thank the Director General of the Minerals and Geoscience Department Malaysia (JMG) and the Director General of the Department of Mineral Resources, Thailand (DMR) for their encouragement, support and funding of this project. Thanks are extended to Mr. Mior Sallehhuddin bin Mior Jadid, the Director of Technical Services Division, Minerals and Geoscience Department Malaysia and Mr. Montri Luengingkasoot, the Director of Bureau of Geological Survey, Department of Mineral Resources, Thailand, for their encouragements during the study. Due thanks are also dedicated to all officers and staffs of the Minerals and Geoscience Department Malaysia and Department of Mineral Resources, Thailand for their involvements in this project either directly or indirectly. The Malaysian and Thai military, provincial and border police officials are duly thanked for their assistance in the security matters. The Malaysian-Thai Working Group would also like to express their gratitude to Dr. Assanee Meesook for his free consultation especially in identifying the fossil samples collected on both Malaysian and Thai sides. Last but not least to all local residences in both sides of the Malaysia-Thailand common border areas for their support and assistance during the fieldworks. iv Litho- and Biostratigraphic Correlations of Chert Beds in Various Rock Units along the Malaysia-Thailand Border by The Malaysian-Thai Working Group EXECUTIVE SUMMARY The Malaysia-Thailand Border Joint Geological Survey Committee (MT-JGSC) had agreed to undertake the study on the litho- and biostratigraphic correlations of the chert beds in various rock units along the Malaysia-Thailand border during the 7th Meeting of the Committee held in Krabi in June 2010. The joint study was scheduled to be carried out in two years duration i.e., in the year 2011 and 2012. The occurrence of chert beds and other radiolarian bearing rock types in various rock units ranging in age from Carboniferous to Triassic along the Malaysia-Thailand border areas has been reported by many previous workers. On the Malaysian side, chert occurs in the lower part of the Kubang Pasu Formation, in the Cherty unit and in the Semanggol Formation. Chert or rather siliceous shale also occurs in the Silurian-Devonian Setul and Mahang Formations. However, no radiolarian is discovered in these older formations so far. On the Thai side, Early Carboniferous radiolarian occurs in the chert beds belonging to the Yaha and Khuan Klang Formations. Early to Middle Triassic radiolarians had been retrieved from thin-bedded limestones at Khao Chiak, Phattalung Province. The oldest chert or rather siliceous shale occurred along the Malaysia-Thailand border area belongs to the Silurian-Devonian Setul Formation. The cherty beds occur in the Lower Detrital Member and Upper Detrital Member of the Setul Formation that are well-exposed in the north western coast of Langgun Island in Langkawi. Cherty beds also occur in the Mahang Formation exposed in central and south Kedah, to the south, outside of the Malaysia-Thailand border area. However, to date, no radiolarian was discovered in these rock units. On the Malaysian side, radiolarian chert occurs in the lower part of the Tournaisian (Lower Carboniferous) Kubang Pasu Formation exposed in the Perlis and Kedah areas. This chert, associated with clastic rocks particularly shale, represents deep marine environtment along the continental margin. Biostratigraphically, three zones of radiolarian assemblages had been recognized; Albaillella deflandrei Zone and Albaillella pseudoparadoxa Zone of Tournaisian age, as well as Albaillella indensis to Latentifistula concentric Zone of Visean age. On the Thai side, the Early Carboniferous radiolarian faunas were reported from two localities in southern Thailand such as the Saba Yoi area in Songkhla Province and the Kabang area in Yala Province. The radiolarian fauna of the Saba Yoi area is quite similar to that of the Entactinia variospina assemblage in Tournaisian (Early Carboniferous). The radiolarian fauna from the Kabang area, Yala Province was assigned to the Albaillella deflandrei Zone which is estimated as upper Tournaisian in age. On the Malaysian side, Permian radiolarian chert beds are represented by the Mangga and Gerik Formations, whilst the Early Permian to Middle Triassic radiolarian chert beds are v represented by the chert in the Cherty unit. The Mangga Formation is well-exposed in western Kelantan, along the East-West highway connecting the Gerik town in Perak and Batu Melintang in Kelantan. The Gerik Formation is well-exposed in the Gerik area, Upper Perak. The Cherty unit is well-exposed in the Pokok Sena and Kuala Ketil areas, Kedah. Prior to the Malaysian-Thai Working Group joint geological survey, the Cherty unit was considered as the lower part of the Permian-Triassic Semanggol Formation. The Cherty unit had been taken out from the Semanggul Formation as it exhibits different characteristics from the Rhythmite and Conglomeratic units of the Semangol Formation in terms of lithostratigraphy, paleontology and age as well as paleoenvironment (The Malaysian and Thai Working Group, 2006). Biostratigraphically, nine zones of Permian radiolarian assemblages had been recognized; Pseudoalbaillella scalprata m. rhombothoracata assemblage Zone of Wolfcampian to Sakmarian (Early Permian to late Early Permian), Pseudoalbaillella longtanensis assemblage Zone of Kungurian age (Middle Permian), Pseudoalbaillella globosa assemblage Zone of Roadian age (Middle Permian), Follicucullus monacanthus assemblage Zone of Wordian (Middle Permian), Follicucullus porrectus assemblage Zone of Capitanian to Wuchiapingian (late Middle Permian to early Late Permian), Neoalbaillella ornithoformis of Wuchiapingian (Late Permian), Neoalbaillella optima assemblage Zone of Wuachiapingian to Changhsingian (Upper Permian), Follicucullus scholasticus of Guadalupian (Late Permian), and Albaillella levis assemblage Zone of Late Permian. On the Thai side, only one zone of radiolarian assemblage of the latest Middle to earliest Late Permian (Capitanian to Wuchiapingian) age had been identified. This radiolarian assemblage zone is reported from the Hat Yai area, Songkhla Province. Biostratigraphically, on the Malaysian side, four zones of Triassic radiolarian assemblages had been identified; Entactinosphaera chiakensis of Early Triassic, Triassocampe coronata of middle Anisian (Middle Triassic), Triassocampe deweri of middle to late Anisian, and Oertlispongus inaequispinosus of Ladinian (Middle Triassic). On the Thai side, three Triassic radiolarian assemblage zones had been recognized; Parentactinia nakatsugawaensis Assemblages Zone of Olenekian to early Anisian in age, Entactinia nikorni Assemblages Zone of Olenekian to Early Anisian (Triassic) in age and Triassocampe deweveri Assemblage Zone of Middle Triassic. The Palaeozoic to Mesozoic radiolarian-bearing rocks in northern Peninsular Malaysia and southern Thailand are represented by the siliceous and calcareous sedimentary rocks such as chert, siliceous shale and limestone. The deposition might occur in different oceanic environments such as in depressions of the continental slope/rise, and in shallow and deep oceanic basins. However, the depositional environment of the radiolarian-bearing rock sequences in Thailand and Malaysia