Lower Carboniferous (Tournaisian) radiolarians from Peninsular Malaysia and their significance

Abstract

Lower Carboniferous (Tournaisian) radiolarians are widespread in Peninsular Malaysia especially in the Western Belt. The radiolarians were recorded in the Kubang Pasu Formation of Kedah and Perlis, Kenny Hill Formation, Selangor, Upper Paleozoic rocks from Nenering, north Perak and the chert block in Langkap, Negeri Sembilan. The radiolarians retrieved from the Kubang Pasu and Kenny Hill Formations exhibit very low specific diversity. The chert from Nenering and Langkap yielded moderate diversity (20 species) and high specific diversity (30 species) respectively. The lithologic association of the Kubang Pasu and Kenny Hill Formations comprises chert overlain by turbiditic sandstone and shale which indicates the depositional environment was in a basin close to a continental margin. The lithologic association of chert from Langkap consists of interbedded chert and shale which is indicative of basinal environment. The widespread distribution of chert is related to high radiolarian productivity during the Tournaisian. The Tournaisian is also known as a hypersiliceous age. The high productivity of radiolarians was related to upwelling cold dense bottom water with contained very rich siliceous material, oxygen, and nutrients. This bottom current was developed at a glacial north-Gondwanan area and flowed southwards. The chert also can be used as a marker bed for Tournaisian age and is very important rock unit to define the base of the Kubang Pasu Formation.