Abstract
The Misogawa Complex is a Mesozoic accretionary complex widely exposed in the eastern Mino Terrane, central Japan. The Misogawa Complex in the Kisofukushima area consists of two lithologic units; one is chert-dominant unit and the other is sandstone-dominant unit. The former is composed of pelagic chert and hemipelagic siliceous mudstone, and the latter is composed of a large amount of sandstone and mudstone. They show various deformation features up to dismembered formation. In the chert-dominant units, chert-clastics sequences that are composed of pelagic chert and overlying trench-fill sediments are repeatedly exposed with imbricate thrusts. The trench-arrival age of the oceanic plate is Late Jurassic and the depositional age of the complex possibly reaches latest Jurassic or earliest Cretaceous on the basis of radiolarian biostratigraphic data obtained from three continuous successions. The trench-arrival age shows the structurally downward younging polarity through the structurally overlying Sawando Complex and the underlying Misogawa Complex. It is inferred that both complexes were formed through continuous subduction-accretion process from late Early Jurassic to latest Jurassic or earliest Cretaceous. Considering lithofacies, structures and radiolarian ages, the Takatori Unit and the Kasama Unit in the Yamizo Mountains and southern part of the Kamiaso Unit in the western Mino Terrane are correlative with the Misogawa Complex.
