Accretion-collision tectonics in mobile belts is one of the most important new topics in solid earth science. A special seminar on this subject, the Oji International Seminar on Accretion Tectonics, was held from the 10th to 16th September, 1981, in Tomakomai, Hokkaido, Japan. It was sponsored by the Japan Society for the Promotion of Science and the Fujihara Foundation of Science, organizers were S. Uyeda, Earthquake Research Institute, University of Tokyo, Amos Nur, Department of Geophysics, Stanford University, and M. Hashimoto, Department of Geology, National Science Museum, Tokyo. More than fifty geoscientists, thirty from Japan and twenty from abroad, met together to present findings from their recent studies and exchange ideas about accretion-collision phenomena in the circum-Pacific mobile belts. Two field days were also spent in the Horokanai area, central Hokkaido, to examine and the Horokanai ophiolite. The the Kamuikotan high-pressure metamorphic rocks latter is a fragment of ancient ocean floor crust that has been obducted onto the Kamuikotan rocks at the time of collision of the Okhotsk Micro-continent with Asia. The seminar was by no means a large congress. However, to the best of our knowledge, it was the first international conference on accretion-collision tectonics. The meeting was highly successful and we believe that it has opened an important new era in the study of plate tectonics.

Proceedings of the Oji International Seminar on Accretion Tectonics, September 1981, Tomakomai, Japan

Inhalt
General.- Break-up and Accretion Tectonics.- North America to Northeast Asia.- Recognition, Character, and Analysis of Tectonostratigraphic Terranes in Western North America.- Tectonostratigraphic Terranes of Alaska and Northeastern USSRA Record of Collision and Accretion.- Accretionary Terranes and Tectonic Evolution of Northeast Siberia.- Accretional and Collisional Eugeosynclinal Folded Systems of the Northwestern Pacific Rim.- Space-Time Distribution of Late Mesozoic to Early Cenozoic Magmatism in East Asia and Its Tectonic Implications.- Hokkaido, North Japan.- Collision Orogenesis and Sedimentation in Hokkaido, Japan.- Mesozoic Arc-Trench Systems in Hokkaido, Japan.- Collision Tectonics in Hokkaido and Sakhalin.- From Subduction to Paleosubductions in Northern Japan.- Disclosing of a Deepest Section of Continental-Type Crust Up-Thrust as the Final Event of Collision of Arcs in Hokkaido, North Japan.- Southwest Japan.- Hida and Mino: Tectonostratigraphic Terranes in Central Japan.- Accretion Tectonics Inferred from Paleomagnetic Measurements of Paleozoic and Mesozoic Rocks in Central Japan.- Accreted Oceanic Reef Complex in Southwest Japan.- Tectonic Environments and Crustal Section of the Outer Zone of Southwest Japan.- Accretionary Melange of Cretaceous Age in the Shimanto Belt in Japan.- Paleomagnetism of the Shimanto Belt in Shikoku, Southwest Japan.- Japan Cenozoic Ophiolite.- Mineoka Ophiolite Belt in the Izu Forearc AreaNeogene Accretion of Oceanic and Island Arc Assemblages on the Northeastern Corner of the Philippine Sea Plate.- Paleomagnetic and Geotectonic Investigation of Ophiolite Suites and Surrounding Rocks in South-Central Honshu, Japan.- Southwest to South Pacific.- A Possible Mechanism of Episodic Spreading of the Philippine Sea.- Tertiary Accretion of Ophiolite Seamounts, North Island, New Zealand.- Roles of Seamount, Rise, and Ridge in Lithospheric Subduction.- Geophysics and Metallogenesis.- Forces Acting on the Subducted Lithosphere Revealed by the Geometry of Deep-Seismic Zones.- Overthrust and Underthrust as a Fundamental Process of Continental Accretion.- Accretion Tectonics and Metallogenesis.