Algorithms for demise and regeneration of accretionary complexes

2022 Fiscal Year Final Research Report

• Project/Area Number: 16K05579
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Geology
• Research Institution: Yamaguchi University
• Principal Investigator: Koji Wakita 山口大学, 地域未来創生センター, 教授(特命) (80358366)
• Project Period (FY): 2016-04-01 – 2023-03-31
• Keywords: 付加体 / 地質学 / 砕屑性ジルコン年代 / 放散虫化石 / メランジュ / 石灰岩 / チャート

Outline of Final Research Achievements

Accretionary prisms constitute one of the most important components of the geological formations in Japan. The large non-metamorphic accretionary complexes in Japan are the Permian, Jurassic, and Cretaceous-Paleogene accretionary complexes. For a long time, it has been a mystery as to why these accretionary complexes formed and why they did not form at other times. In this study, we have clarified the relationship between the ebb and flow of magmatic activity and the formation of accretionary complexes by examining the ages of detrital zircons contained in Paleo-Mesozoic strata. This study has also explained the collision process of giant submarine volcanoes, which was key to the end of the accretionary complex by means of geological investigation in the Permian accretionary complex of the Akiyoshi Belt.

Free Research Field

付加体地質学

Academic Significance and Societal Importance of the Research Achievements

近年、日本各地でジオパーク活動が広がりを見せ、ブラタモリなどの人気番組でも取り上げられるなど、一般の人々にとっても地質学は身近なものになりつつある。付加体は日本各地に分布し、各地の重要な基盤岩となっている。本研究では、付加体の形成過程について最新の知識を公表し、一般市民に対しても分かりやすく発信し、ジオパーク観光などで、付加体の正しい知識を身につけ、日本の地質の深淵に触れることを可能にした。