http://www.paper.edu.cn Precambrian Research 136 (2005) 177–202 Late Archean to Paleoproterozoic evolution of the North China Craton: key issues revisited Guochun Zhaoa,∗, Min Suna, Simon A. Wildeb, Li Sanzhongc a Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong b Department of Applied Geology, Curtin University of Technology, Bentley 6012, Western Australia c College of Marine Geosciences, Ocean University of China, 266003, Qingdao, China Received 1 July 2003; accepted 28 October 2004 Abstract A recently proposed model for the evolution of the North China Craton envisages discrete Eastern and Western Blocks that developed independently during the Archean and collided along the Trans-North China Orogen during a Paleoproterozoic orogenic event. This model has been further refined and modified by new structural, petrological and geochronological data obtained over the past few years. These new data indicate that the Western Block formed by amalgamation of the Ordos Block in the south and the Yinshan Block in the north along the east-west-trending Khondalite Belt some time before the collision of the Western and Eastern Blocks. The data also suggest that the Eastern Block underwent Paleoproterozoic rifting along its eastern continental margin in the period 2.2–1.9 Ga, and was accompanied by deposition of the Fenzishan and Jingshan Groups in Eastern Shandong, South and North Liaohe Groups in Liaoning, Laoling and Ji’an Groups in Southern Jilin, and possibly the Macheonayeong Group in North Korea. The final closure of this rift system at ∼1.9 Ga led to the formation of the Jiao-Liao-Ji Belt. In the late Archean to early Paleoproterozoic, the western margin of the Eastern Block faced a major ocean, and the east-dipping subduction beneath the western margin of the Eastern Block led to the formation of magmatic arcs that were subsequently incorporated into the Trans-North China Orogen. Continued subduction resulted in a major continent- continent collision, leading to extensive thrusting and high-pressure metamorphism. The available age data for metamorphism and deformation in the Trans-North China Orogen indicate that this collisional event occurred at about 1.85 Ga ago, resulting in the formation of the Trans-North China Orogen and final amalgamation of the North China Craton. © 2004 Elsevier B.V. All rights reserved. Keywords: North China Craton; Archean; Paleoproterozoic; Collision; Rifting 1. Introduction ∗ Corresponding author. Tel.: +852 28578203; The North China Craton is a general term used to fax: +852 25176912. refer to the Chinese part of the Sino–Korea Craton. It E-mail address: [email protected] (G. Zhao). covers ∼1.5 million square kilometers in most of north- 0301-9268/$ – see front matter © 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.precamres.2004.10.002 转载 中国科技论文在线 http://www.paper.edu.cn 178 G. Zhao et al. / Precambrian Research 136 (2005) 177–202 Fig. 1. Tectonic map of China showing the major cratons and younger orogens (Zhao et al., 2001b). ern China, the southern part of northeastern China, In- and Qian, 1995; Song et al., 1996; Bai and Dai, 1998; ner Mongolia, the Bohai Bay and the northern part of Wu et al., 1991, 1998; Kusky and Li, 2003). Uncon- the Yellow Sea. The craton is bounded by the early formably overlying the basement are Mesoproterozoic Paleozoic Qilianshan Orogen and late Paleozoic Cen- unmetamorphosed volcanic-sedimentary successions, tral Asian Orogenic Belt to the west and north, re- called the Changcheng-Jixian-Qingbaikou system, and spectively, and the Mesozoic Qinling–Dabie and Su-Lu Phanerozoic cover. ultrahigh-pressure metamorphic belts to the south and Conventionally, the North China Craton has been east, respectively (Fig. 1). The basement of the North considered to be composed of Archean to Paleoprotero- China Craton consists of variably exposed Archean to zoic basement formed during four distinct tectonic cy- Paleoproterozoic rocks, including TTG gneiss, gran- cles, named the Qianxi (>3.0 Ga), Fuping (3.0–2.5 Ga), ite, charnockite, migmatite, amphibolite, greenschist, Wutai (2.5–2.4 Ga) and Luliang¨ (2.4–1.8 Ga) cycles pelitic schist, Al-rich gneiss (khondalite), banded iron (Huang, 1977; Ma and Wu, 1981; Wu et al., 1991; formation (BIF), calc-silicate rock and marble (Huang Zhao, 1993; Shen and Qian, 1995). Correspondingly, et al., 1986; Jahn et al., 1987; Ma et al., 1987; Qiao four tectonic events, named the Qianxi, Fuping, Wutai et al., 1987; Kroner¨ et al., 1988; He et al., 1992; Liu and Luliang¨ movements, were postulated at ∼3.0 Ga, et al., 1992; Shen et al., 1992; Sun et al., 1992; Shen ∼2.5 Ga, ∼2.4 Ga and ∼1.8 Ga, respectively (Huang, 中国科技论文在线 http://www.paper.edu.cn G. Zhao et al. / Precambrian Research 136 (2005) 177–202 179 1977; Ma et al., 1987; Cheng, 1994; Bai and Dai, 1998). blocks (e.g. Wu et al., 1998; Wu and Zhong, 1998; These tectonic cycles/movements were built upon ev- Zhao et al., 1998, 2001b; Li et al., 2000; Zhai et al., idence of a few “unconformities”, K–Ar, Rb–Sr and 2000; Zhai and Liu, 2003; Zhai et al., 2003; Wu et al., conventional multigrain U–Pb zircon geochronology, 2000; Kusky and Li, 2003). To resolve these controver- and misconceptions that much of the basement of the sial issues, geologists from China, Australia, Germany, craton was dominated by supracrustal rocks, and that USA and Canada have carried out extensive structural, high-grade metamorphic rocks were older than low- metamorphic, geochemical and geochronological in- grade ones. However, geological mapping carried out vestigations in some key areas of the craton over the in the late 1980s and early 1990s reveals that the ma- last few years, and obtained numerous new geological jority of felsic gneisses cropping out in the craton are data and provided new interpretations for these key is- metamorphosed TTG and granitic plutons (Jahn and sues (e.g. Wang et al., 1996, 1997, 2001; Li and Liu, Zhang, 1984; Zhai et al., 1985, 1990; Jahn et al., 1987, 1997; Li et al., 2001a, 2001b, 2004; Wilde et al., 1997, 1988; Jahn and Ernst, 1990; He et al., 1992), and 1998, 2002, 2003, 2004; Cawood et al., 1998; Kroner¨ et some so-called “unconformities” between these tec- al., 1998, 2001, 2002, 2004; Wu and Zhong, 1998; Wu tonic cycles are regional-scale ductile shear zones (Li et al., 2000; Zhao et al., 1998, 1999c, 2000a, 2001b, and Qian, 1991). Moreover, new geochronological data 2002a, 2003a, 2003b; Guo et al., 1999, 2001, 2002, indicate that not all the low-grade metamorphic rocks 2004; Halls et al., 2000; Liu et al., 2000, 2002a, 2002b, are younger than the high-grade rocks. For example, the 2004a, 2004b; Zhai et al., 2000, 2003, 2004; Kusky low-grade Wutai Complex has protolith ages similar to et al., 2001; Guo and Zhai, 2001; Zhai and Liu, 2003; those of the high-grade Fuping and Hengshan Com- Passchier and Walte, 2002; Ge et al., 2003; Wang et al., plexes (Wilde et al., 1997, 1998, 2004; Kroner¨ et al., 2003; Kusky and Li, 2003; O’Brien et al., 2004; Wu et 2004; Guan et al., 2002; Zhao et al., 2002a). Because al., 2004). In this contribution, we examine a number of these, the polycyclic model and its main assumption of important issues related to the late Archean to Pa- that the North China Craton has a single basement have leoproterozoic evolution of the North China Craton. been abandoned in recent studies (Li et al., 1990; Wu These include the nature and origin of its component et al., 1991, 1998; Wang et al., 1996; Wu and Zhong, parts, development of its eastern margin, the presence 1998). or otherwise of Archean ophiolites, the distribution and Major advancements in understanding the geolog- tectonic nature of granulite facies rocks, and the tim- ical history of the North China Craton have been ing of its final amalgamation. On the basis of these new achieved in the past decade following discovery of geological data, we present a synthesis of our current fragments of ancient oceanic crust, melanges,´ high- understanding of the evolution and amalgamation of pressure granulites and retrograded eclogites, and the North China Craton. crustal-scale ductile shear zones and thrusts in the cen- tral part of the craton (Li et al., 1990; Li and Qian, 1991; Bai et al., 1992; Zhai et al., 1992, 1995; Zhang et 2. Tectonic subdivision of the North China al., 1994; Wang et al., 1996, 1997; Zhao et al., 1999a, Craton 2001a; Guo et al., 2002). These discoveries have led to a broad consensus that the basement of the North 2.1. Tectonic subdivision China Craton is composed of different blocks/terranes that developed independently and finally collided to One of the most controversial issues concerning the form a coherent craton (Wu et al., 1998; Wu and Zhong, late Archean to Paleoproterozoic geology of the North 1998; Zhang et al., 1998; Zhai et al., 2000; Zhao, 2001; China Craton is the tectonic division of the basement Li et al., 2000; Kusky and Li, 2003). However, it still of the craton, and several proposals have been put for- remains controversial as to how the craton should be ward (Wu and Zhong, 1998; Wu et al., 1998; Zhang subdivided and where the collisional boundaries are et al., 1998; Zhai et al., 2000; Li et al., 2000; Kusky located, the nature of the late Archean to Paleopro- and Li, 2003). For example, Zhang et al. (1998) di- terozoic tectonothermal events, and the timing and tec- vided the basement of the North China Craton into 15 tonic processes involved in the amalgamation of the blocks/terranes, but they did not expound what were 中国科技论文在线 http://www.paper.edu.cn 180 G.