1:45 PM - 2:00 PM
[SGL18-01] Tectonic significance of early Paleogene collision complex in the Hidaka belt, central Hokkaido, NE Asia: A review
Keywords:Hidaka belt, Hidaka Supergroup, greenstone, depositional age, collision complex, central Hokkaido
The Hidaka belt in the central axis zone of Hokkaido, NE Asia has been one of the areas where geological research is most delayed in Japan, and their depositional ages and tectonic settings were not clear until now. It has been considered as late Cretaceous accretionary complex like the Shimato belt in southwestern Japan. From 2018 to 2024, our research group has been published a series of journal publications in the Hidaka belt, and a lot of new knowledge was obtained regarding the sedimentary rock complex in the Hidaka belt, their depositional ages, and the origin of the associated greenstones (Nanayama et al., 2021, 2018, 2022; Yamasaki and Nanayama, 2018, 2020; Yamasaki et al., 2021, 2024). The results can be summarized five points as bellows.
(1) Clastic sediments of sedimentary complexes in the Hidaka (Hidaka Supergroup) are within the depositional age between Paleocene and early Eocene.
(2) The Hidaka Supergroup is distributed widely across the east-west width of more than 100 km. However, its internal structure and age differences are not clear, and it cannot be explained by the accretionary growth model which becomes younger in the eastward.
(3) There is no significant age difference in the eruption age of the three bands of in situ basalts (N-MORB) recognized in the Hidaka belt, and if this is explained by the ridge subduction model, it can be explained only one event.
(4) The Hidaka Supergroup was a sedimentary body mainly composed of turbidite facies filled in the sea area between the Paleo-Japan arc and the Paleo-Kuril arc in early Paleogene age. After 47 Ma, according to the joining of two arc-trench systems, significant deformation was occurred it. I guess these sedimentary complexes formed a collision complex between the Paleo-Japan arc and the Paleo-Kuril arc.
(5) The Tatsuushi and Erimo formations has shown that the Hidaka Belt has been active as a right-lateral strike-slip fault system since the late Oligocene. The Chikapupetsu and Shii-Tokachigawa formations in Tomuraushi area are marine deposits that formed during the early Miocene between deposition of the late Oligocene Tatsuushi and Erimo formations and the middle Miocene Kamishiyubetsu Formation, while the right-lateral strike-slip fault system was active.
References:
Nanayama et al., 2018, U-Pb zircon ages of the Nakanogawa Group in the Hidaka Belt, northern Japan: Implications for its provenance and the protolith of the Hidaka metamorphic rocks. Island Arc, 27, e12233.
Nanayama et al., 2021, The emplacement of in situ greenstones in the northern Hidaka belt: the tectonic relationship between subduction of the Izanagi-Pacific ridge and Hidaka magmatic activity. Island Arc, 30(1), e12403.
Nanayama et al., 2022, Origin and evolution of the Paleo-Kuril arc inferred from detrital zircon U-Pb chronology in eastern Hokkaido, NE Asia. Island Arc, 31(1), e12458.
Yamasaki and Nanayama, 2018, Immature intra-oceanic arc-type volcanism on the Izanagi Plate revealed by the geochemistry of the Daimaruyama greenstones in the Hiroo Complex, southern Hidaka Belt, central Hokkaido, Japan. Lithos, 302/303, 224-241.
Yamasaki and Nanayama, 2020, Three types of greenstone from the Hidaka belt, Hokkaido, Japan: Insights into geodynamic setting of northeastern margin of the Eurasia plate in the Paleogene. Journal of Mineralogical and Petrological Sciences, 115, 29-43.
Yamasaki et al., 2021, Subduction of the Izanagi–Pacific Ridge–transform intersection at the northeastern end of the Eurasian Plate. Geology, 49, 952–957.
Yamasaki et al., 2024, Possible partial melting and production of felsic melt in a Jurassic oceanic plateau of the Izanagi Plate: Insights from 159 Ma plagiogranites from northern Japan. International Geology Review, 66:5, 993-1022, DOI: 10.1080/00206814.2023.2224426
(1) Clastic sediments of sedimentary complexes in the Hidaka (Hidaka Supergroup) are within the depositional age between Paleocene and early Eocene.
(2) The Hidaka Supergroup is distributed widely across the east-west width of more than 100 km. However, its internal structure and age differences are not clear, and it cannot be explained by the accretionary growth model which becomes younger in the eastward.
(3) There is no significant age difference in the eruption age of the three bands of in situ basalts (N-MORB) recognized in the Hidaka belt, and if this is explained by the ridge subduction model, it can be explained only one event.
(4) The Hidaka Supergroup was a sedimentary body mainly composed of turbidite facies filled in the sea area between the Paleo-Japan arc and the Paleo-Kuril arc in early Paleogene age. After 47 Ma, according to the joining of two arc-trench systems, significant deformation was occurred it. I guess these sedimentary complexes formed a collision complex between the Paleo-Japan arc and the Paleo-Kuril arc.
(5) The Tatsuushi and Erimo formations has shown that the Hidaka Belt has been active as a right-lateral strike-slip fault system since the late Oligocene. The Chikapupetsu and Shii-Tokachigawa formations in Tomuraushi area are marine deposits that formed during the early Miocene between deposition of the late Oligocene Tatsuushi and Erimo formations and the middle Miocene Kamishiyubetsu Formation, while the right-lateral strike-slip fault system was active.
References:
Nanayama et al., 2018, U-Pb zircon ages of the Nakanogawa Group in the Hidaka Belt, northern Japan: Implications for its provenance and the protolith of the Hidaka metamorphic rocks. Island Arc, 27, e12233.
Nanayama et al., 2021, The emplacement of in situ greenstones in the northern Hidaka belt: the tectonic relationship between subduction of the Izanagi-Pacific ridge and Hidaka magmatic activity. Island Arc, 30(1), e12403.
Nanayama et al., 2022, Origin and evolution of the Paleo-Kuril arc inferred from detrital zircon U-Pb chronology in eastern Hokkaido, NE Asia. Island Arc, 31(1), e12458.
Yamasaki and Nanayama, 2018, Immature intra-oceanic arc-type volcanism on the Izanagi Plate revealed by the geochemistry of the Daimaruyama greenstones in the Hiroo Complex, southern Hidaka Belt, central Hokkaido, Japan. Lithos, 302/303, 224-241.
Yamasaki and Nanayama, 2020, Three types of greenstone from the Hidaka belt, Hokkaido, Japan: Insights into geodynamic setting of northeastern margin of the Eurasia plate in the Paleogene. Journal of Mineralogical and Petrological Sciences, 115, 29-43.
Yamasaki et al., 2021, Subduction of the Izanagi–Pacific Ridge–transform intersection at the northeastern end of the Eurasian Plate. Geology, 49, 952–957.
Yamasaki et al., 2024, Possible partial melting and production of felsic melt in a Jurassic oceanic plateau of the Izanagi Plate: Insights from 159 Ma plagiogranites from northern Japan. International Geology Review, 66:5, 993-1022, DOI: 10.1080/00206814.2023.2224426