Triassic to Middle Jurassic radiolarians from pelagic cherts in the Nanjō Mountains, Southwest Japan - Part 1. Imajō district

Abstract

Satoshi Nakae,(2013) Triassic to Middle Jurassic radiolarians from pelagic cherts in the Nanjō Mountains, Southwest Japan -Part 1. Imajō district. Bull. Geol. Surv. Japan, vol. 64 (3/4), 3 figures, 2 tables, 5 plates. Abstract:The Nanjō Mountains located in the central region of Fukui Prefecture, Southwest Japan, are chiefly underlain by a sedimentary complex consisting of various rock-types such as basalt, limestone, chert, mudstone and sandstone. Among these rocks within the mountains, 27 chert outcrops were explored for their radiolarian content. In the studied Imajō district, the 14 rock samples from 10 localities yielded moderately-to poorly-preserved radiolarian remains as a result. Most of the samples contained Triassic to Middle Jurassic species, with Spumellaria and Entactinaria dominant among the Triassic faunas and Nassellaria dominant among the Jurassic faunas. The description and faunal analysis of these radiolarians revealed that the cherts in the Imajō district indicate a long range in age from the Olenekian? stage to the Bajocian stage.

Triassic to Middle Jurassic radiolarians from pelagic chertsin the Nanjō Mountains, Southwest Japan – Part 2. Kanmuri Yama district

“…Consequently, this study presents a systematic description of all radiolarian species extracted from the cherts in the Kanmuri Yama district as the second report. Those from the Imajō district have already been described in the first report by Nakae (2013).…”