Paleoenvironments, paleogeography and basins of Cretaceous system in Japanese island arcs reconstructed from integrated stratigraphic correlation

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K05688
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Stratigraphy/Paleontology
• Research Institution: Ibaraki University
• Principal Investigator: Ando Hisao 茨城大学, 理工学研究科(理学野), 教授 (50176020)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 白亜紀 / 日本列島 / 古日本陸弧－海溝系 / 複合層序対比 / 古環境変動 / 古地理 / 堆積盆解析 / 古生態

Outline of Final Research Achievements

Based on stratigraphy, sedimentary facies, sequence stratigraphy, biostratigraphy and radiometric dating, Cretaceous strata deposited in the Paleo-Japan continental arc-trench system are correlated over the Japanese island arcs on a wide scale. The paleoenvironments, paleogeography and paleoecosystems of the system during the Cretaceous time are reconstructed, taking the tectonic setting in the east Asia into account. Furthermore, several newly investigated topics of representative strata such as the Yezo, Kuji, Soma-Nakamura, Futaba, and Nakaminato groups in Northeast Japan are reported from the viewpoints of terrestrial and marine biota and their characteristics.

Free Research Field

層序古生物学

Academic Significance and Societal Importance of the Research Achievements

現在の自然豊かな日本列島の基盤である地質体は，古第三紀以降の被覆岩体を除くと，大半は白亜紀の堆積岩や火成岩，変成岩である．鉱物・燃料資源を含む日本の大地の恵みは白亜紀に形成されたといっても過言ではない．本研究は，日本列島が，もともとは古アジア大陸の一部として成立し，その後の地質学的歴史の中で列島になったという，いわば日本列島のルーツを辿る点で社会的にも影響力があり，学術的にも重要な示唆を与える．