Late Cretaceous uplift history of the Cretaceous volcanic arc in Southwest Japan: Provenance analysis of the Yuasa–Aridagawa basin based on U–Pb zircon ages

Abstract

The Ryoke Metamorphic complex has undergone low‐P/T metamorphism and was intruded by granitic magmas around 100 Ma. Subsequently, the belt was uplifted and exposed by the time deposition of the Izumi Group began. The tectonic history of uplift, such as the timing and processes, are poorly known despite being important for understanding the spatiotemporal evolution of the Ryoke Metamorphic Belt. U–Pb zircon ages from sedimentary rocks in the forearc and backarc basins are useful for constraining uplift and magmatism in the provenance. U–Pb dating of detrital zircons from 12 samples (four sandstones and eight granitic clasts) in the Yuasa–Aridagawa basin, a Cretaceous forearc basin in the Chichibu Belt of Southwest Japan, gave mostly ages of 60–110 Ma. Granitic clasts contained in conglomerate suggest that granitic intrusions predate the formation of Coniacian and Maastrichtian conglomerate. Emplacement ages of granitic bodies originated from granitic clasts in Coniacian conglomerate are (110.2 ±1.3) Ma, (106.1 ±1.8) Ma, (101.8+5.8–3.8) Ma, and (95.3 ±1.4) Ma; for granitic clasts in Maastrichtian conglomerate, (89.6 ±1.8) Ma, (87.3+2.4–1.8) Ma, (85.7 ±1.2) Ma, and (82.7 ±1.2) Ma. The results suggest that detrital zircons in the sandstones were mainly derived from volcanic eruptions contemporaneous with depositional age, and plutonic rocks of the Ryoke Metamorphic Belt. Zircon ages of the granitic clast samples also indicate that uplift in the provenance began after Albian and occurred at least during the Coniacian to Maastrichtian. Our results, together with the difference of provenance between backarc and forearc basins suggest that the southern marginal zone of the Ryoke Metamorphic Belt was uplifted and supplied a large amount of clastic materials to the forearc basins during the Late Cretaceous.

Lithological, structural, and chronological relationships between the Sanbagawa Metamorphic Complex and the Cretaceous Shimanto Accretionary Complex on the central Kii Peninsula, SW Japan

“…Chough & Sohn, ; Imaoka et al, ; Kim et al, ; Nakajima, Takahashi, Imaoka, & Shimura, ; Sato, Matsuura, & Yamamoto, ; Yamada, Takizawa, Tanase, & Kawada, ). In addition, Shunori, Takeuchi, and Yamamoto () conducted detrital zircon U–Pb dating on the rocks of the Cretaceous forearc basin (Yuasa–Aridagawa basin) on the Kii Peninsula, and they reported that the Cretaceous granitic rocks (Ryoke granitic rocks) were providing material to the forearc basin shortly after their formation. Therefore, during this period, it is possible that the detrital zircons derived from the Cretaceous igneous rocks that had been supplied to the trench.…”

Provenance Change in Cretaceous–Paleogene Fore-arc in Western Hokkaido: U–Pb Dating of Detrital Zircons from the Yezo Group

“…Maruyama et al, 1997;Isozaki et al, 2010 な Aoki et al, 2012; 中 畑 ほ か, 2016a, b;Ikeda et al, 2016;Shunori et al, 2018; 長谷川ほか, 2019, 2020 …”