Tectonic Evolution of the North China Block: From Orogen to Craton to Orogen

TLDR: The North China Craton contains one of the longest, most complex records of magmatism, sedimentation, and deformation on Earth, with deformation spanning the interval from the Early Archaean (3.8 Ga) to the present as mentioned in this paper.

Abstract: The North China Craton contains one of the longest, most complex records of magmatism, sedimentation, and deformation on Earth, with deformation spanning the interval from the Early Archaean (3.8 Ga) to the present. The Early to Middle Archaean record preserves remnants of generally gneissic meta-igneous and metasedimentary rock terranes bounded by anastomosing shear zones. The Late Archaean record is marked by a collision between a passive margin sequence developed on an amalgamated Eastern Block, and an oceanic arc–ophiolitic assemblage preserved in the 1600 km long Central Orogenic Belt, an Archaean–Palaeoproterozoic orogen that preserves remnants of oceanic basin(s) that closed between the Eastern and Western Blocks. Foreland basin sediments related to this collision are overlain by 2.4 Ga flood basalts and shallow marine–continental sediments, all strongly deformed and metamorphosed in a 1.85 Ga Himalayan-style collision along the northern margin of the craton. The North China Craton saw relative quiescence until 700 Ma when subduction under the present southern margin formed the Qingling–Dabie Shan–Sulu orogen (700–250 Ma), the northern margin experienced orogenesis during closure of the Solonker Ocean (500–250 Ma), and subduction beneath the palaeo-Pacific margin affected easternmost China (200–100 Ma). Vast amounts of subduction beneath the North China Craton may have hydrated and weakened the subcontinental lithospheric mantle, which detached in the Mesozoic, probably triggered by collisions in the Dabie Shan and along the Solonker suture. This loss of the lithospheric mantle brought young asthenosphere close to the surface beneath the eastern half of the craton, which has been experiencing deformation and magmatism since, and is no longer a craton in the original sense of the word. Six of the 10 deadliest earthquakes in recorded history have occurred in the Eastern Block of the North China Craton, highlighting the importance of understanding decratonization and the orogen–craton–orogen cycle in Earth history. The Archaean North China (Sino-Korean) Craton (NCC) occupies about 1.7 10 km in northeastern China, Inner Mongolia, the Yellow Sea, and North Korea (Bai 1996; Bai & Dai 1996, 1998; Fig. 1). It is bounded by the Central China orogen (including the Qinling–Dabie Shan–Sulu belts) to the SW, and the Inner Monglia–Daxinganling orogenic belt (the Chinese part of the Central Asian Orogenic Belt) on the north (Figs 1 and 2). The western boundary is more complex, where the Qilian Shan and Western Ordos thrust belts obscure any original continuity between the NCC and the Tarim Block. The location of the southeastern margin of the craton is currently under dispute (e.g. Oh & Kusky 2007), with uncertain correlations between the North and South China Cratons and different parts of the Korean Peninsula. The Yanshan belt is an intracontinental orogen that strikes east–west through the northern part of the craton (Davis et al. 1996; Bai & Dai 1998). The NCC includes several micro-blocks and these micro-blocks amalgamated to form a craton or cratons at or before 2.5 Ga (Geng 1998; Zhang 1998; Kusky et al. 2001, 2004, 2006; Li, J. H. et al. 2002; Kusky & Li 2003; Zhai 2004; Polat et al. 2005a, b, 2006), although others have suggested that the main amalgamation of the blocks did not occur until 1.8 Ga (Wu & Zhang 1998; Zhao et al. 2001a, 2005, 2006; Liu et al. 2004, 2006; Guo et al. 2005; Kroner et al. 2005a, b, 2006; Wan et al. 2006a, b; Zhang et al. 2006). Exposed rock types and their distribution in these micro-blocks vary considerably from block to block. All rocks .2.5 Ga in the blocks, without exception, underwent the 2.5 Ga metamorphism, and were intruded by 2.5–2.45 Ga granitic sills and related bodies. Nd TDM models show that the main crustal formation ages in the NCC are between 2.9 and 2.7 Ga (Chen & Jahn 1998; Wu et al. 2003a, b). Emplacement of mafic dyke swarms at 2.5–2.45 Ga has also been From: ZHAI, M.-G., WINDLEY, B. F., KUSKY, T. M. & MENG, Q. R. (eds) Mesozoic Sub-Continental Lithospheric Thinning Under Eastern Asia. Geological Society, London, Special Publications, 280, 1–34. DOI: 10.1144/SP280.1 0305-8719/07/$15 # The Geological Society of London 2007.