First evidence Jurassic-Cretaceous radiolaria in Menanga Formation, Lampung, Sumatra, Indonesia

Abstract

Research on Menanga Formation in Lampung and surrounding areas is still limited, especially research on paleontology. The purpose of this study was to identify the presence of radiolarian fossils in the Menanga Formation. Field observations were carried out at two site in Way Sabu, Pesawaran and Gunungkasih, Tanggamus, Lampung. Twelve samples were extracted from interbedded siltstone and claystone for radiolaria fossils. There were four samples that had radiolarian fossils. Radiolaria from genus Tetraditryma sp., Paronaella sp., Pantanellium sp., Holocryptocanium sp., Archaeocenosphaera sp., Napora sp., Sethocapsa sp., and Orbiculiforma sp. were found in the Menanga Formation indicate Jurassic to Cretaceous age. Based on radiolaria assemblage, Menanga Formation was probably positioned within a warm water current system in the low latitude Mesotethys. The exposed Menanga Formation caused by a collision between Woyla terrane and West Sumatra terrane that occurred in the Late Cretaceous.