Bulletin of the Mizunami Fossil Museum

Bulletin of the Mizunami Fossil Museum No. 1

Summarized the previous works on the Seto group which has a wide distribution in the Tokai region, its geology, paleontology, correlation and geologic history are discussed. In the neighbourhood of Mizunami City, the Seto group divided into the lower Toki-guchi ceramic clay bed and the upper gravel bed. The former consists of various kind of clays and sands bearing many plant fossils as Pinus trifolia and Metasequoia disticha. It was made under a small swamp environment. The Toki gravel bed is composed of pebbles and cobbles of Paleozoic cherts, sandstones and hornfels, and of so-called quartz-porphyries with a few granites indicating existence of the Paleo-Kiso River in this area.

The geologic age of the Seto group is the Pliocene to the Early Pleistocene