Bulletin of the Geological Society of Malaysia, Volume 43, Dec. 1999, pp. 491 – 502
Jabatan Geologi, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor D.E., Malaysia
Abstract: The dacitic tuff-chert sequence is exposed at several road-cuts along the road to Tebedu 2.5 km to 4 km west of Piching. The sequence is composed of bedded dacitic tuff interbed with cherts and mudstone. The sequence is informally assigned as the Binong bed which is closely related to the Serian Volcanics and may represents the top part of the formation. Twenty seven taxa of Radiolaria were identified from the chert samples. The occurrence of Parahsuum simplum Yao, Parahsuum directiporatum (Rust), Praecocaryomma media Pessagno and Poisson, Praeconocaryomma decora Yeh, Paracanoptum anulatum (Pessagno and Poisson), Canutus izeensis Pessagno and Whalen, and Paracanoptum rugosum (Pessagno and Poisson) suggests that the radiolarian faunas belong to the Parahsuum directiporatum Zone. Based on the radiolarian faunas, the whole chert-dacitic tuff sequence was deposited during Pliensbachian-early Toarcian, Early Jurassic. The radiolarian chert was deposited in a deep marine marginal basin environment very close to an island arc.