The Triassic Stratigraphy and Ammonite Fauna of Japan

Abstract

The Triassic ammonites of Japan are known from the southern Kitakami Massif, the Kwanto Massif, the Maizuru Zone, and the Islands of Shikoku and Kyushu. Based upon them a biostratigraphical correlation of the Japanese Triassic is attempted. The four ammonite zones recognized in the Lower Triassic and the Middle Triassic are correlative with the standard ammonite zones of the world, whereas the Upper Triassic ammonite fauna is in-sufficiently known for such purpose. Besides descriptions and discussions on the Triassic stratigraphy and paleontology, remarks are given on the sedimentary environment and tectonic history of the Japanese Triassic Epoch.