Phanerozoic accretionary history of Japan and the western Pacific margin

Abstract

It is generally accepted that oceanic plate subduction has occurred along the eastern margin of Asia since about 500 Ma ago. Therefore, the Japanese Islands have a >500 Ma history of oceanic plate subduction in their geological records. In this paper, the accretionary history of the Japanese Islands is divided into six main stages based on the mode and nature of tectonic events and the temporal gaps in the development of accretionary processes. In the first stage, oceanic plate subduction and accretion started along the margin of Gondwana. After detachment of the North and South China blocks in Devonian time, accretionary complexes developed along island arcs offshore of the South and North China blocks. After the formation of back arc basins such as the Japan Sea, accretionary processes occurred only along the limited convergent margin, e.g. Nankai Trough. Detrital zircons of sandstones revealed the accretionary history of Japan. An evaluation of a comprehensive dataset on detrital zircon populations shows that the observed temporal gaps in the development of the Japanese accretionary complexes were closely related to the intensity of igneous activity in their provenance regions. Age distributions of detrital zircons in the accretionary complexes of Japan change before and after the Middle Triassic period, when the collision of the South and North China blocks occurred.

Magmatic record of the Mesozoic geology of Hainan Island and its implications for the Mesozoic tectonomagmatic evolution of SE China: effects of slab geometry and dynamics in continental tectonics

“…Permian magmatic arc products are not exposed extensively in SE China, except on Hainan Island where Guadalupian calcalkaline granites (Wuzhishan granites; et al 2006) exist, and in Anhui Province where Guadalupian volcanic tuff deposits with calc-alkaline geochemistry are well preserved in the Permian sedimentary record . However, the widespread occurrence of Permian detrital zircons in the Upper Permian through Jurassic sedimentary rock sequences in SE China has been interpreted to have sourced from a magmatic arc in the region , including the proto-Japan arc (Duan et al 2018;Hara et al 2018;Wakita et al 2020).…”

“…Large grey arrows show the convergence direction of the palaeo-Pacific (Izanagi) oceanic plate with respect to Eurasia. Data are from Faure & Natal'in (1992), Maruyama et al (1997), Lee (1999), WD Sun et al (2007) Wakita (2020). See text for discussion of the model.…”

Tokoro Belt (NE Hokkaido): an exhumed, Jurassic – Early Cretaceous seamount in the Late Cretaceous accretionary prism of northern Japan

“…Oceanic plates with normal mid-ocean ridge basalt (N-MORB) geochemical affinities and large abyssal plains are generally subducted smoothly without leaving a trace, whereas those with large seamounts, oceanic plateaus and rugged seafloor bathymetry, which form major asperities on downgoing slabs, commonly disrupt the subduction processes, causing upper plate deformation, mega-earthquakes and punctuation in magmatism (Cloos, 1993;Tankut et al 1998;Dominguez et al 2000;Dilek, 2003;Furnes et al 2014). While parts of such asperities become entirely subducted, large portions of them may become accreted as thrust sheets into subduction-accretion complexes contributing significantly to continental growth (Dilek, 2003;Sarifakioglu et al 2017;Wakita et al 2019). Considering the fact that much of the modern western Pacific Ocean floor is covered with seamounts, seamount chains and oceanic plateaus, the arrival of these bathymetric highs and structures at the western Pacific Rim trenches in the geological future should affect the continental margin tectonics there, as has already been demonstrated by seismic investigations along the Central and South American continental margins (Kopp et al 2004;Watts et al 2016;Morrell, 2016).…”

Subduction zone processes and crustal growth mechanisms at Pacific Rim convergent margins: modern and ancient analogues

“…The Japanese archipelago comprises mainly late Palaeozoic -Cenozoic subduction-accretion complexes with exhumed high-P/T metamorphic complexes (Nishiyama et al 2020), in situ mafic to felsic intrusive-extrusive rock sequences and fragments of fossil oceanic lithosphere. This island chain represents a 450 Ma history of multiple subduction-accretion events, punctuated by shortlived mid-ocean ridge, seamount and island arc collisions along the western Pacific convergent margin (Maruyama et al 1997;Wakita et al 2018). Development of the Japanese archipelago is therefore widely considered as an archetype of an accretionary orogen (Jahn, 2010).…”