Disclosing of a deepest section of continental-type crust up- thrust as the final event of collision of arcs in Hokkaido, north Japan.

The metamorphic sequence in the main zone of the Hidaka metamorphic belt represents almost the whole section through the continent-type crust which was obducted on the accretion complex along the collision zone of two island arcs. The exposed crust section has about 23 km in thickness, consisting of granulite facies gneisses at the base, amphibolite facies gneisses in the middle to upper and greenschist facies rocks and unmetamorphosed sediments at the top. The crust might have been developed in an island arc environment during the Paleogene to Early Miocene and thrust up E to W, having been affected by the westward collision of the third island arc, the Kuril arc, in the Late Miocene to Pliocene time. -Authors