Cyclic formation and stabilization of Archean lithosphere by accretionary orogenesis: Constraints from TTG and potassic granitoids, North China Craton

Abstract

Accretionary orogens are major sites of modern continental growth, yet their role in the development of Archean continental crust remains enigmatic. Diverse granitoid suites from tonalite‐trondhjemite‐granodiorite (TTG) to potassic granitoids appeared during late Archean, representing a period of major continental formation and stabilization. In this study, whole‐rock geochemical and zircon U‐Pb and Lu‐Hf isotopic data are reported for Neoarchean granitoid gneisses from the Northern Liaoning Terrane, northeastern North China Craton (NCC). Older granitoid gneisses (~2592–2537 Ma) define three magmatic zones migrating from southeast to northwest, each showing a common magmatic evolution from high‐pressure TTGs to medium‐/low‐pressure TTGs and potassic granitoids. They have depleted zircon ƐHf(t) of +0.5 to +8.7. Younger ~2529–2503 Ma potassic granitoids and TTGs occur throughout the terrane, which are marked by variable zircon ƐHf(t) of −4.7 to +8.1, and are coeval with regional high‐grade metamorphism. Petrogenetic modeling and changing Sr/Y and (La/Yb)N of the granitoids suggest that the crust experienced episodic thickening and thinning and became progressively evolved through development of potassic granitoids and sedimentary successions. The metavolcanic basement to the granitoids display tholeiitic to calc‐alkaline affinities, together with the top‐to‐the‐northwest thrusting and associated volcanogenic massive sulfide‐type Cu‐Zn deposits, suggesting cyclic crustal formation of Northern Liaoning within an accretionary orogen with a SE‐dipping subduction polarity. Cyclic crustal thickening and thinning is related to tectonic switching from advancing to retreating relations between the downgoing and overriding plate. After ~2530 Ma, this accretionary system accreted to the ancient continental nucleus of NCC (Anshan‐Benxi Terrane), signifying final lithosphere stabilization.

LA–ICP–MS zircon U Pb dating, Lu Hf, Sm Nd geochronology and tectonic setting of the Mesoarchean mafic and felsic magmatic rocks in the Sangmelima granite-greenstone terrane, Ntem Complex (South Cameroon)

“…Similar subduction-accretion tectonic model have been put forward for other Archean cratons worldwide (e.g. Cawood et al, 2009;Hawkesworth et al, 2016;Wang et al, 2017;Yu et al, 2019), thus suggesting the emergence of plate tectonics and associated accretionary orogens around 3.2-3.0 Ga (e.g. Hawkesworth et al, 2016;Brenner et al, 2020;reference therein).…”

Geochemistry, geochronology, and geodynamic implications of mafic‐felsic dykes from the Hadamengou area, north‐western North China Craton

“…During the Late Neoarchean (2.6–2.5 Ga), the seven micro‐blocks within the NCC began to amalgamate through oceanic subduction and continent‐continent collisions (Figure 1b; Tang & Santosh, 2018; Wan et al, 2015; Zhai, Bian, & Zhao, 2000; Zhai et al, 2005; Zhai, 2014). The NCC underwent extensive tectono‐thermal events during the amalgamation process and generated abundant intrusive rocks in the NCC, including tonalite‐trondhjemite‐granodiorite (TTG), associated with minor gabbroic and dioritic rocks (Gong, Zhang, Yu, Li, & Hou, 2012; Wan et al, 2015, 2017; Wang et al, 2017; Zhai, 2014; Zhou, Zhao, Zhai, Gao, & Sun, 2014). Previous studies identified that widespread magmatic rocks of the Late Neoarchean are distributed in the Jining Block, especially the Daqingshan region and adjacent Guyang area.…”

Zircon U–Pb ages and geochemistry of the late Archaean granitoids in the Zanhuang Complex: Records of an arc–continent collision event at the end of Archaean

“…Later, they revised the model so that both oceans closed at ~1,880 Ma (Trap et al, ; Trap et al, ). Another group of scholars (Deng et al, ; Deng et al, ; Kusky et al, ; Wang et al, , ; Wang, Cawood, et al, ; Wang, Kusky, et al, ; Wang, Kusky, et al, ) suggested that the WZD belongs to the Fuping arc, and the western part of the CZD (or the Guandu Group) was a ~2.5 Ga tectonic mélange belt and suture between the Eastern Block and the Fuping arc, suggesting an arc–continent collision in the late Neoarchaean. Li, Santosh, Teng, and He (, ) and Tang, Santosh, Tsunogae, and Maruoka (, ) proposed a model in which the Eastern Block and the Zanhuang arc collided at ~2.3 Ga, followed by back‐arc extension and rifting.…”

“…The NCC also shows such a distinct transition during 3.0–2.5 Ga period. These granitoids have been studied separately by many scholars (e.g., Diwu et al, ; Fu et al, ; Liu et al, ; Wang et al, ; Wang, Cawood, et al, ; Yang, Wu, Wilde, & Zhao, ). However, a comprehensive study of these diverse granitoids has not been carried out in the central NCC.…”