2022 Fiscal Year Final Research Report
Paleoenvironmental studies of terrestrial and marine sequences in Northwest Pacific region during Paleocene-Eocene Thermal Maximum.
| Project/Area Number |
20K04153
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 17050:Biogeosciences-related
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| Research Institution | Hokkaido Research Organization |
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Principal Investigator |
Hayashi Keiichi 地方独立行政法人北海道立総合研究機構, 産業技術環境研究本部 エネルギー・環境・地質研究所, 主査 (30707906)
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| Co-Investigator(Kenkyū-buntansha) |
高嶋 礼詩 東北大学, 学術資源研究公開センター, 教授 (00374207)
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| Project Period (FY) |
2020-04-01 – 2023-03-31
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| Keywords | 暁新世-始新世境界温暖化極大（PETM） / 北西太平洋 / 根室層群 / 羽幌層 / 渦鞭毛藻シスト化石層序 / 古一次生産 |
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| Outline of Final Research Achievements |
The Paleocene-Eocene Thermal Maximum (PETM) is well known as the prominent short-term global warming event at the Paleocene-Eocene boundary. In this study, we examined the integrated stratigraphy of dinocyst-carbon isotope of the Tomikawa Formation, the uppermost part of the Nemuro Group, because of the formation is considered to be formed during early Paleocene to early Eocene. As a result, it is revealed that the negative carbon isotope excursion of PETM is in the upper middle part of the Tomikawa Formation.
Furthermore, we examined the paleoenvironment, especially the sea suaface primary productivity, by dinocyst assemblage changes across the PETM. The productivity gradually declined with the global warming in the late Paleocene, and very poor in the latest Paleocene. After that, the productivity turned to increase onset of the PETM. It is considered that the high productivity in the sea surface caused by enhanced run-off, because the humid and warm environment in the PETM period.
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| Free Research Field |
地質学，古生物学，古環境学
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| Academic Significance and Societal Importance of the Research Achievements |
本研究は，PETMの研究において，これまで研究の少なかった地域である北西太平洋域においてPETM時の陸域～海域の古環境を解明することにある．特に，本研究では，深海域で形成された根室層群と浅海～陸上で形成された羽幌層の２つの異なる環境で形成された地層において古環境を比較検討することで，当時の陸域および海域の環境変動を明らかにできる．
また，PETMは大量の二酸化炭素などが大気中に放散されて生じたと考えられることから，現在進行中の温暖化のアナログ（相似事例）と考えられており，PETM時に生じた古環境変動の解明は，現在，進行中の温暖化の将来予測のための重要な知見となる．
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