Appalachian-style multi-terrane Wilson cycle model for the assembly of South China Shoufa Lin1,2*, Guangfu Xing3, Donald W. Davis4, Changqing Yin5, Meiling Wu1, Longming Li2, Yang Jiang3, and Zhihong Chen3 1Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada 2School of Resources and Environment, Hefei University of Technology, Hefei 230026, China 3China Geological Survey (Nanjing Center), Nanjing 210016, China 4Department of Earth Sciences, University of Toronto, Toronto, Ontario M5S 3B1, Canada 5School of Earth Sciences and Engineering, Sun Yat-Sen University, Guangzhou 510275, China ABSTRACT northeastern Jiangnan belt consists of two ter- The evolution of South China involved accretion-collision of multiple terranes from the ranes (sensu lato), Jiuling and Huaiyu, separated Proterozoic to the Mesozoic. Zircon U-Pb ages, Hf data, and structural data indicate that by the Northeast Jiangxi fault (Fig. 1). the Cathaysia block consists of two terranes, West Cathaysia and East Cathaysia, separated by a newly recognized major strike-slip fault. We propose that West Cathaysia was part of a Jiuling Terrane microcontinent that originated from a Grenvillian-aged orogen in the Rodinia supercontinent, The Jiuling terrane is characterized by a thick East Cathaysia originated from an Indosinian-aged orogen in the Paleo-Tethyan regime to sequence of middle Neoproterozoic (ca. 850– the south and was translated to the east of West Cathaysia through strike-slip motion, and 825 Ma) turbidites and minor volcanic rocks the early Paleozoic Wuyi-Yunkai orogeny was a result of direct collision of West Cathaysia (e.g., the Xikou Group) and includes the ca. 833 with a yet-unidentified terrane that rifted away after the collision. We conclude that a multi- Ma Fuchuan ophiolite (e.g., Yin et al., 2013). terrane Wilson cycle (multi-terrane accretion-collision, large-scale strike-slip motion, and These rocks are generally interpreted to have separation of two terranes by post-collisional rifting along the suture zone) characterizes the formed in an arc−back-arc system. history of South China and may be a common feature of orogens. Huaiyu Terrane INTRODUCTION progressive closing and reopening of oceans, The Huaiyu terrane is characterized by a Wilson (1966) proposed a basic model for that became known as the Wilson cycle. This series of late Mesoproterozoic to early Neopro- the tectonic history of eastern North America model has since been refined using detailed evi- terozoic supracrustal rocks that are distinctly (Grenville and Appalachian orogens), involving dence for multi-terrane accretion-collision and older than those in the Jiuling terrane (Fig. 2). strike-slip faulting (e.g., van Staal et al., 2009; Major units include (1) the Tieshajie Formation 0 Lin et al., 2013). (Fig. 3), a ca. 1160 Ma continental rift sequence 110 E North China Craton SShuangxiwuhuangxiwu G. ShuangxiwuShuangxiwSShanghaihuanghai South China is interpreted to have formed (Li et al., 2013); (2) the Tianli schist (Fig. 3), a Kongling Qinling-Dabie F Complex Shangh261ai by the amalgamation of two blocks, Yangtze Mesoproterozoic metasedimentary succession NEJ u g y and Cathaysia (Fig. 1), but the proposed timing that was deformed and metamorphosed at ca. n i li a Yangtze Xikou G. u iu CChencahencai of amalgamation varies wildly, corresponding 1.0 Ga (Li et al., 2007); and (3) the Shuangxiwu JJiulin HHuaiyu 300 N CComplexomplex to various known tectono-thermal events, from Group (Fig. 1), a ca. 970–890 Ma juvenile arc lt WWuuyyishanishan 1832 be JSF n Paleoproterozoic (Dong et al., 2015) to early Neo- sequence that was deformed and metamorphosed na F ia g ia F s Fig. 3 n s y proterozoic (ca. 1.0–0.9 Ga, Grenvillian age; e.g., before ca. 850 Ma (Li et al., 2009). The terrane ia t y W a JJiangnan belt s a NNWFF h e h t t a Li et al., 2007) to middle Neoproterozoic (ca. 820 also contains ophiolite slivers, including the ca. WWesta CCathaysia t C s Ma, Jinning or Sibao age; e.g., Zhao et al., 2011; 970 Ma Zhangshudun (Xiwan) ophiolite (Fig. 3) a EEast Cathaysia Yin et al., 2013) to early Paleozoic (ca. 460–420 that was obducted at ca. 880 Ma (Li et al., 2008). CCathaysiathaysia 200 km Yunkai 0 Ma; Caledonian age) to Mesozoic (ca. 250–230 The Huaiyu terrane has been interpreted as 120 E HHongong Ma; Indosinian age). In this paper, we propose an part of a composite terrane that formed by the KKongong alternative interpretation that is closer to the Wil- amalgamation of multiple terranes at ca. 1.0– Yangtze Precambrian n South son cycle. That is, South China formed by accre- 0.88 Ga (Yin et al., 2013). basement Jiangna 0 China athaysia tion-collision of multiple terranes, where each of 20 N Greater West C Cathaysia the above tectono-thermal events corresponds to Timing of Amalgamation of the Jiuling and 1100 E an accretional-collisional event and was modified Huaiyu Terranes Figure 1. Tectonic framework of eastern by later rifting and large-scale strike-slip motion. The pre–820 Ma units in both terranes are South China (modified from Cawood et al., metamorphosed to greenschist facies and uncon- 2013). NEJF—Northeast Jiangxi fault; JSF— YANGTZE BLOCK AND JIANGNAN BELT formably overlain by middle Neoproterozoic Jiangshan-Shaoxing fault; NWFF—Northwest The Yangtze block contains an Archean– (815–750 Ma) (e.g., the Banxi Group) to middle Fujian fault; G.—Group. Black numbers 261 and 1832 are U-Pb zircon ages (in Ma) (meta- Paleoproterozoic crystalline basement. Along Silurian cover (Fig. 2). This unconformity cor- morphic and magmatic, respectively; see Data its southeastern margin is a Neoproterozoic fold responds to the Jinning or Sibao orogeny, which Repository [see footnote 1] for sources). belt called the Jiangnan belt (or orogen) that was related to the amalgamation of the two ter- is generally considered as the collision zone ranes and the closure of the Jiuling back-arc *E-mail: [email protected] between the Yangtze and Cathaysia blocks. The basin (e.g., Yin et al., 2013). GEOLOGY, April 2018; v. 46; no. 4; p. 319–322 | GSA Data Repository item 2018090 | https://doi.org/10.1130/G39806.1 | Published online 9 February 2018 ©GEOLOGY 2018 The Authors.| Volume Gold 46 |Open Number Access: 4 | www.gsapubs.orgThis paper is published under the terms of the CC-BY license. 319 Downloaded from http://pubs.geoscienceworld.org/gsa/geology/article-pdf/46/4/319/4102178/319.pdf by guest on 24 September 2021 Neoproterozoic ages. They are intruded by early Greater West Cathaysia terrane East (A) West Cathaysia Jiuling West Cathaysia terrane Paleozoic mostly felsic intrusions. Age Huaiyu terrane Cathaysia terrane terrane Ten new samples were collected from West Ga Devonian and younger (D–) D– Cathaysia for zircon sensitive high-resolution 0.40 ca. 815 Ma to middle Silurian ?–O3 ion microprobe (SHRIMP) U-Pb geochronology 0.80 Banxi Group ? Igneous ? and Hf isotope analysis. The results are sum- zircon Fuchuan 0.84 ophiolite marized below and in Figures 3 and 4. More Xikou details are given in the GSA Data Repository1. Metamorphic 0.88 Group & t zircon equivalents A pegmatite dike, a biotite gabbro, a two- Number 0.92 Zhangshudun mica granite, and a quartz diorite (samples C, E, ophiolite Age (Ga) 0.96 F, and H, respectively) yield magmatic ages of Shuangxiwu 441 ± 3 Ma, 446 ± 4 Ma, 440 ± 2 Ma, and 447 1.00 Group (B) East Cathaysia Jiangshan-Shaoxing fault ± 4 Ma, respectively. These magmatic ages are 1.20 Tianli Tieshajie Northwest Fujian faul schist Formation coeval with metamorphic ages of 440 ± 4 Ma, 446 ± 6 Ma, 450 ± 10 Ma, and 443 ± 7 Ma from 1.50 Metamorphic two biotite gneisses, a felsic metavolcanic rock, zircon 2.00 Northeast Jiangxi fault and an amphibolite (samples A, D, G and M, Igneous Age? zircon 2.50 respectively). A porphyritic granite (sample L) 0 40 0 40 Number 0 10 0 80 0 80 yields a younger age of 404 ± 2 Ma. Gneissic 1.00 melanosome and a felsic metavolcanic rock 2.00 (samples B and G) yield magmatic ages of 907 Number Age (Ga) 3.00 ± 10 Ma and 911 ± 7 Ma, respectively, with evidence for a slightly younger metamorphic 4.00 Hf model age histograms event present in some samples (e.g., sample B; Figure 4. Compilation of new (colored) and Unconformity Magmatism Deformation/ metamorphism see the Data Repository). previous results of Lu-Hf analyses for zircons Mostly sedi- Volcano- from West Cathaysia (A) and East Cathaysia sedimentary rocks Ophiolite mentary rocks The new data, supplemented by previous (B), South China. Insets are histograms of Figure 2. Summary of main characteristics of results, indicate the following characteristics two-stage Hf model ages of magmatic zir- cons. CHUR—chondritic uniform reservoir; terranes of study area, South China. ?–O3— for West Cathaysia: (1) the Precambrian base- late Ordovician and older, base undefined. See ment rocks were affected by a major magmatic DM—depleted mantle. See Data Repository (see footnote 1) for more information. Data Repository (see footnote 1) for sources and metamorphic event in the early Paleozoic for Hf data. (ca. 460–420 Ma), called the Wuyi-Yunkai or “Caledonian” orogeny (Li et al., 2010; Wang et paths. Peak metamorphism reached upper al., 2013); (2) their protoliths mostly have ages amphibolite to granulite/eclogite facies (>1 GPa CATHAYSIA BLOCK between ca. 1.00 and ca. 0.91 Ga (Figs. 3 and in metapelite; e.g., Zhao and Cawood, 1999), The Cathaysia block is divided into two ter- 4; see also Wang et al., 2014); and (3) two-stage with associated partial melting. ranes, East Cathaysia and West Cathaysia, with zircon Hf model ages (TMD2) cluster between 1.5 contrasting geological histories (Figs.