Middle Permian Radiolarians from the siliceous mudstone block near Pos Blau, Ulu Kelantan and their significance

Abstract

A large siliceous sedimentary block was exposed in the vicinity Pos Blau, Ulu Kelantan. The block is a part of mélange in the Bentong-Raub Suture Zone. The lower part of the block is composed of ribbon chert and the upper part consists of interbedded siliceous mudstone and tuffaceous mudstone. Five samples from the siliceous mudstone yielded very low number of individuals but fairly high number of species. Fourteen radiolarians taxa were identified. The radiolarians are divided into two assemblage zones namely Pseudoalbaillella fusiformis Zone and Follicucullus monacanthus Zone indicating Middle Permian age. The occurrence of tuffaceous material in Middle Permian siliceous rock in Peninsular Malaysia was related to volcanic activities as a result of collision between Palaeo-Tethys oceanic crust and the East Malaya terrane. The source of the tuffaceous material was from the East Malaya terrane. The tuffaceous sediments became widespread in Late Permian and Triassic. This indicates the early stage of closing the Palaeo-Tethys. Abstrak: Satu blok batuan sedimen bersilika yang besar terdedah pada kawasan berhampiran dengan Pos Blau, Ulu Kelantan. Blok ini sebahagian daripada mélange dalam Zon Sutura Bentong-Raub. Bahagian bawah blok terdiri daripada rijang ribbon dan bahagian atas terdiri daripada selang-lapis batu lumpur bersilika dan batu lumpur bertuf. Lima sampel daripada batu lumpur bersilika menghasilkan bilangan individu yang sedikit tetapi bilangan spesies agak tinggi. Empat belas taksa radiolarian telah dikenal pasti. Radiolaria dibahagikan kepada dua zon himpunan iaitu Zon Pseudoalbaillella fusiformis dan Zon Follicucullus monacanthus yang menunjukkan usia Perm Tengah. Kewujudan bahan bertuf dalam batuan bersilika Perm Tengah di Semenanjung Malaysia berkait dengan kegiatan volkano hasil daripada pelanggaran antara kerak lautan Palaeo-Tethys dan teran Malaya Timur. Punca bahan bertuf itu daripada teran Malaya Timur. Sedimen bertuf tersebar luas pada Perm Akhir dan Trias. Ini menunjukkan tahap awal penutupan Palaeo-Tethys.