Lithos 208–209 (2014) 104–117

Contents lists available at ScienceDirect

Lithos

j ourna l homepage: www.e lsev ie r .com/ locate / l i thos

2.2 Ga magnesian andesites, Nb-enriched basalt-andesites, and adakiticrocks in the Lüliang Complex: Evidence for early Paleoproterozoicsubduction in the North China Craton

Chaohui Liu a,⁎, Guochun Zhao b, Fulai Liu a, Jianrong Shi c

a Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, Chinab Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kongc Tianjin Institute of Geology and Mineral Resources, Tianjin 300170, China

⁎ Corresponding author. Tel.: +86 10 88332013.E-mail address: denverliu82@gmail.com (C. Liu).

http://dx.doi.org/10.1016/j.lithos.2014.08.0250024-4937/© 2014 Elsevier B.V. All rights reserved.

a b s t r a c t

a r t i c l e i n f o

Article history:Received 18 June 2014Accepted 29 August 2014Available online 16 September 2014

Keywords:Magnesian andesiteNb-enriched basaltLüliang ComplexNorth China CratonEarly Paleoproterozoic

The Lüliang Complex is located at the western margin of the middle segment of the Trans-North China Orogen,along which the Western and Eastern Blocks amalgamated to form the basement of the North China Craton.The complex consists of the Paleoproterozoic granitic plutons and meta-supracrustal rocks, of which the latterare subdivided into the Jiehekou, Lüliang, Yejishan, and Heichashan/Lanhe Groups. A meta-volcanic rock fromthe Yejishan Group gives a magmatic zircon U–Pb age of 2188 ± 48 Ma and εHf(t) values of +0.06 to +5.42.Based on the geochemical characteristics, four different ~2.2 Ga igneous rock suits have been identified in theLüliang Complex. The calc-alkaline basalts and andesites show the geochemical features of typical ‘normal’ arcvolcanics with pronounced LREE enrichments relative to HREE, negative Nb, Ta, P and Ti anomalies andεNd(t) values of−2.69 to +2.14. The adakitic rocks are characterized by high Na2O/K2O ratios, weak to positiveEu anomalies, positive Sr and Ba but negative Nb and Ti anomalies, and relatively clustered and near to zeroεNd(t) values. The Nb-enriched basalts and andesites have higher Nb, Zr and TiO2 contents, higher Nb/Ta(14.4–19.3) and Nb/U (20.6–23.2) ratios than the majority of arc basalts and andesites and relatively variableεNd(t) values (−1.54 to +3.02). The magnesian andesites are characterized by anomalously high MgO, Cr andNi contents and have εNd(t) values of −3.90 to +1.17. The occurrence of adakitic rocks, Nb-enriched basaltsand andesites and magnesian andesites has been described from many modern arcs featuring subduction ofoceanic slab. Therefore, we suggest that similarmechanismmay have played an important role in the productionof the ~2.2 Ga igneous rocks in the Lüliang Complex and thus thefinal collision between the Eastern andWesternBlocks along the TNCO must have happened at some time after ~2.2 Ga.

© 2014 Elsevier B.V. All rights reserved.

1. Introduction

The Trans-North China Orogen (TNCO) in the North China Craton(NCC), one of the oldest cratonic blocks in the world, has been studiedon the lithology, structural style, metamorphic evolution, geochemistryand geochronology in the last decades (e.g. Faure et al., 2007; Kröneret al., 2005a, 2005b; Kusky and Li, 2003; Polat et al., 2005; Wang et al.,2010b; Wilde et al., 2002; Zhai et al., 2005; Zhao et al., 2012). Differentmodels for the tectonic subdivision and amalgamation of the NCC havebeen proposed to explain the important tectonothermal events, espe-cially the ~2.5 Ga and ~1.85 Ga events (Faure et al., 2007; Kusky,2011; Kusky and Li, 2003; Santosh, 2010; Trap et al., 2007, 2012;Wang et al., 2010a; Zhai and Santosh, 2011; Zhai et al., 2005; Zhaoet al., 2005). In the last decades, an increasing lines of evidence for the2.2–2.1 Ga tectonothermal events in the TNCO have been reported in

the Hengshan Complex (Kröner et al., 2005b; Wang et al., 2010b;Zhao et al., 2011), Wutai Complex (Du et al., 2010, 2013; Peng et al.,2005; Wilde, 2002; Wilde and Zhao, 2005), Fuping Complex (Guanet al., 2002; Zhao et al., 2002), Lüliang Complex (Geng et al., 2000; Liuet al., 2012a, 2014a; Zhao et al., 2008), Zanhuang Complex (Liu et al.,2012b; Xie et al., 2012; Yang et al., 2011) and Zhongtiao Complex(Sun et al., 1990) in the TNCO. However, the petrogenesis and tectonicsetting of the 2.2–2.1 Ga igneous rocks remain controversial, partlyresulting in the differentmodels for the tectonic evolution of the craton.Zhai (2004, 2011), Zhai and Peng (2007) and Du et al. (2013) suggestedthat these igneous rocks were related with the 2.30–1.95 Ga rift eventsafter ~2.5 Ga cratonization of the NCC. On the contrary, Zhao et al.(2005), Liu et al. (2012a, 2014a) and Wang et al. (2010b) consideredthesemagmatic rocks to be subduction-related at an Andean-style con-vergent margin or in a marginal arc-back-arc basin system. Therefore,the nature and tectonic significance of the tectonothermal events at2.2–2.1 Ga and their relevance to the tectonic evolution of the TNCO isof particular importance.

105C. Liu et al. / Lithos 208–209 (2014) 104–117

A rock association of adakites, magnesian andesites (MA) and Nb-enriched basalts and andesites (NEBA) with ‘normal’ arc basalts andandesites has been reported from Cenozoic arcs featuring subductionof hot, young (b20 Ma) oceanic lithosphere (Drummond et al., 1996;Kelemen, 1995; Martin, 1999). Such an association is also known fromNeoarchean greenstone terranes of the Dharwar craton (Manikyambaet al., 2009), Superior (Polat and Kerrich, 2001), Baltic block(Shchipansky et al., 2004) and the NCC (Guo et al., 2013; Peng et al.,2012a, 2012b; Wang et al., 2004). In this paper, we report new zirconU–Pb and Lu–Hf isotopic, whole-rock geochemical and Sm–Nd isotopicdata for the meta-volcanics in the Yejishan Group in the Lüliang Com-plex. Combined with the published geochemical and geochronologicaldata, we suggest that the ~2.2 Ga meta-igneous rocks in the LüliangComplex include an association of adakitic rock, MA and NEBA. Basedon the results, we evaluate the petrogenesis of these rocks and comparethese to counterparts in Cenozoic arc with a view to further understandthe tectonic evolution of the TNCO in the early Paleoproterozoic.

2. Geological setting

The NCC is composed of Archean to Paleoproterozoic metamorphicbasement overlain by Mesoproterozoic to Cenozoic unmetamorphosedcover (Zhao et al., 2012). Asmentioned above, a number ofmodels havebeen proposed for the tectonic subdivision and amalgamation of theNCC (Faure et al., 2007; Kusky, 2011; Kusky and Li, 2003; Santosh,2010; Trap et al., 2007, 2012; Wang et al., 2010b; Zhai and Santosh,2011; Zhao et al., 2005), most of which agree the division of the NCCinto the Eastern and Western Blocks and emphasize the importance ofcontinent–continent collisional belts to the tectonic evolution of theNCC. The two blocks collided along the NS-trending TNCO (Fig. 1;Zhao et al., 2005), which is also called the Central Orogenic Belt(Kusky and Li, 2003) or the Jinyu Belt (Zhai and Peng, 2007; Zhai andSantosh, 2011). The Eastern Block is subdivided into the LongangBlock (also called the Yanliao Block; Santosh, 2010) and the LangrimBlock, which are separated by the Liao-ji Belt (Zhai and Santosh, 2011)or the Jiao-Liao-Ji Belt (Li et al., 2004, 2005, 2006, 2010, 2012b; Liuet al., 2013c, d, e, 2014b; Lu et al., 2008; Luo et al., 2004, 2008; Tam

Fig. 1. Tectonic subdivision ofModified after Zhao et al. (20

et al., 2011, 2012a, b, c; Wang et al., 2014a; Zhang et al., 2014a; Zhouet al., 2008), whereas the EW-trending Khondalite Belt (also called theFengzhen Belt or Inner Mongolian Suture Zone; Zhai and Peng, 2007;Santosh, 2010; Zhai and Santosh, 2011) subdivides the Western Blockinto the Yinshan and Ordos Blocks (Zhao et al., 2005; Xia et al., 2006a,b, 2008; Yin et al., 2009, 2011, 2014; Zhao, 2009; Li et al., 2011a,2011b; Wang et al., 2011; Liu et al., 2014c; Zhang et al., 2014b).

The TNCO, a nearly NS-trending ~1200 km long and 100–300 kmwide belt across the central part of the NCC (Fig. 1), is composedof Neoarchean to Paleoproterozoic TTG gneisses, meta-supracrustalrocks (metamorphosed sedimentary and volcanic rocks), syn- to post-tectonic granites and mafic dykes. Geochemical and isotopic studiessuggest that the dominant Neoarchean to Paleoproterozoic rocksrepresent arc-related juvenile crust with minor reworked basement(Liu et al., 2002, 2004, 2005, 2012a; Sun et al., 1992; Wang et al.,2004, 2014b, 2014c). Ancient oceanic fragments and mélange havebeen identified in the Jingangku Formation of the Wutai Complex(Polat et al., 2005; Wang et al., 1996, 1997). Most recently, syn-tectonicforeland basin deposits represented by the younger sequence-set of thelow-grade supracrustal successions have been found in the Wutai,Lüliang, Zanhuang and Zhongtiao Complexes (Faure et al., 2007; Liuet al., 2013a; Trap et al., 2007). The TNCO also possesses numerous struc-tural andmetamorphic features as classical indicators of collision tecton-ic, such as linear structural belts characterized by strike-slip ductile shearzones, large-scale thrusting and folding, transcurrent tectonics, sheathfolds and mineral lineations (Li et al., 2010; Trap et al., 2007; Zhanget al., 2007, 2009, 2012), high-pressure granulites and retrogradeeclogites in the Hengshan, Huai'an, Xuanhua and Chengde Complexes(Guo et al., 2002, 2005; Zhai et al., 1992, 1995; Zhao et al., 2001) andclockwise metamorphic P–T paths involving near-isothermal decom-pression (Zhao et al., 2001; Xiao et al., 2011; Qian et al., 2013). Theselithotectonic features contrast with those in the Eastern and WesternBlocks and led Zhao et al. (2000) to propose that the TNCO is acontinent–continent collisional belt, along which the Eastern andWestern Blocks amalgamated to form the coherent basement of theNCC. Available metamorphic ages obtained from metamorphic zirconsand monazites in different complexes of the TNCO are consistent at

the North China Craton.05).

106 C. Liu et al. / Lithos 208–209 (2014) 104–117

~1.85 Ga, which is interpreted as the timing of the collisional event lead-ing to the final cratonization of the NCC (Guan et al., 2002; Guo et al.,2005; Kröner et al., 2005a, 2005b, 2006; Liu et al., 2006; Wang et al.,2010a; Zhao et al., 2002, 2008).

The Lüliang Complex is situated at the western margin of thecentral segment of the TNCO (Fig. 1) and consists of Paleoproterozoicgranitic plutons and meta-supracrustal rocks (Fig. 2; Geng et al., 2000,2006; Zhao et al., 2008; Liu et al., 2012a). The granitoid rocks havebeen subdivided into pre-tectonic TTG (tonalitic–trondjhemitic–granidioritic) gneisses, syn-tectonic gneissic granites and post-tectonicmassive granites (Zhao et al., 2008). The pre-tectonic TTG gneissesinclude the 2499 Ma Yunzhongshan TTG gneiss (Zhao et al., 2008),2375 Ma Gaijiazhuang porphyritic gneiss (Zhao et al., 2008) and2182–2151 Ma Chijianling–Guandishan TTG gneiss (Du et al., 2012;Geng et al., 2000; Liu et al., 2009a; Zhao et al., 2008), and geochemicaldata indicate that these rocks are mostly calc-alkaline and formed in acontinental arc setting (Liu et al., 2009a). It is worthy to note that theYunzhongshan TTG gneiss has been considered equivalent to the2520–2475 Ma Hengshan and Fuping TTG gneisses to the northeast ofthe Lüliang Complex (Zhao et al., 2008). The syn-tectonic gneissicgranites are mainly distributed in the southern Lüliang Complex andrepresented by the 1832 Ma Huijiazhuang gneissic granite, which

Fig. 2. (A) A simplified geological map of the Lüliang Complex (modified after Zhao e

intrudes the Chijianling-Guandishan TTG gneiss and contain its xeno-liths (Zhao et al., 2008). The post-tectonic massive granites include the~1800 Ma Luyashan charnockite (Geng et al., 2000, 2006; Zhao et al.,2008), 1807 Ma Lucaogou porphyritic granite (Zhao et al., 2008) and~1800 Ma Tangershang–Guandishan massive granite (Geng et al.,2006; Zhao et al., 2008), all of which intrude the Chijianling–Guandishan TTG gneiss or the Yunzhongshan TTG gneiss. On the otherway, the meta-supracrustal rocks in the Lüliang Complex have beensubdivided into the Jiehekou, Lüliang, Yejishan andHeichashan/LanxianGroups (Fig. 2; Yu et al., 1997a; Geng et al., 2000).

The Jiehekou Group is located in the western part of the complex(Fig. 2) and consists mainly of graphite-bearing pelitic gneisses/schists,quartzites, fine-grained felsic paragneisses, graphite marbles, calc-silicate rocks and minor amphibolites (Wan et al., 2000). U–Pb detritalzircon dating results in the upper sequence of the group have an agerange between 2.3 and 2.0 Ga and the metamorphic zircons gave agesaround1.85Ga,which suggests that the Jiehekou grouphas beendepos-ited in the period of 2.0–1.85 Ga (Liu et al., 2013b;Wan et al., 2006; Xiaet al., 2009). Based on the similarities in the rock assemblage andgeochemical features of the Jiehekou Group and the “khondalite series”in the Western Block, which crop out along the northern and easternmargins of the Ordos Block respectively, they are proposed to represent

t al., 2008); (B) a cross section through the middle part of the Lüliang Complex.

107C. Liu et al. / Lithos 208–209 (2014) 104–117

stable continental margin deposits surrounding the block (Liu et al.,2013b; Wan et al., 2006; Zhao et al., 2005). On the contrary, the dis-covery of igneous plutons and metamorphic volcanics in the groupled Liu et al. (2012a) to interpret it as the active continental marginproducts.

The Lüliang Group is distributed only in the central part of the com-plex (Fig. 2) and consists predominantly of amphibolite- to greenschist-facies metamorphosed sedimentary rocks in the lower sequence andvolcanic rocks in the upper sequence (Yu et al., 1997a). The protolithsof thesemeta-sedimentary rocks are considered to have sourcedmainlyfrom the Lüliang and Taihua complexes in the TNCO, and they were de-posited during the period between 2.2 and 2.1 Ga, based on the ages ofthe youngest detrital zircons and the Daorengou adamellite intrudingthe group (Liu et al., 2014a). For the upper sequence, Geng et al.(2000) reported a Sm–Nd whole-rock isochron age of 2351 ± 56 Mafrom amphibolites and a single zircon U–Pb age of 2360 ± 95 Mafrom ameta-rhyolite, both interpreted as their rock-forming ages. How-ever, Yu et al. (1997a) reported single zircon U–Pb ages of 2051 ± 68and 2099 ± 41 Ma for a meta-basalt and a meta-rhyolite respectively,also interpreted as the timing of the volcanic eruption. Most recently,Liu et al. (2012a) reported a LA-ICP-MS magmatic zircon U–Pb age of2213 ± 47 Ma and a metamorphic zircon age of 1832 ± 56 Ma for ametabasalt from the group. Similar zircon crystallization ages havealso been obtained for the metabasites (2209–2178 Ma; Liu et al.,2014a) and feldspar porphyritic rocks (2189–2186 Ma; Du et al.,2012) from the upper sequence. Based on the geochemistry of meta-volcanics in the group, Yu et al. (1997b) and Geng et al. (2003)suggested that the Lüliang Group developed in a continent marginalrift environment. However, Faure et al. (2007), Liu et al. (2012a) andLiu et al. (2014a) interpreted the group as having formed in amagmaticarc and/or a back-arc basin environment.

The Yejishan Group is distributed along a narrow, NE–SW-trendingbelt in the northwestern part of the complex (Fig. 2). The grouphas been subdivided into the Qingyangshuwan, Bailongshan, andChengdaogou Formations (Geng et al., 2003), all of which weremetamorphosed in subgreenschist- to amphibolite-facies. The lowestQingyangshuwan Formation is composed of ~635 m thick basalconglomerates, quartzites and phyllites interbedded with minor meta-volcanics. These terrigenous deposits show vertical facies changingfrom coarse clastic sediments into finer-grained siliciclastic rocks, sug-gesting that they were deposited in a graben-related environment(SBGMR, 1989). The basal conglomerates consist of pebble-sized clastsof quartzite, granite, pegmatite, gneiss and marble (in decreasingorder of abundance; SBGMR, 1989). Conformably overlying theQingyangshuwan Formation is the Bailongshan Formation which con-sists of more than 1500 m-thick bed of metabasites interlayered withphyllites and quartzites in the lower part. Widespread pillow lavas pre-served in the formation suggest a submarine eruption (Geng et al.,2003). The Chengdaogou Formation is more than 900 m thick andhas a conformable contact with the underlying amphibole schists ofthe Bailongshan Formation. The main lithologic sequence of the forma-tion is thick layer conglomerates and coarse-grained sandstoneswith large-scale tabular oblique bedding and mud crack structures(Liu et al., 2009b). Geng et al. (2000) reported a zircon U–Pb age of2124 ± 38 Ma for a meta-volcanic rock from the Bailongshan Forma-tion, which is consistent with the youngest age peak of 2086 ± 10 Mafrom a meta-sandstone in the same formation (Liu et al., 2011). Morerecently, Liu et al. (2012a) reported an older zircon U–Pb age of2210 ± 13 Ma for a meta-subvolcanic rock from the BailongshanFormation. For the Qingyangshuwan Formation, the youngest detritalzircon age of 1835 ± 24 Ma from the metamorphosed clastic rocksplaces constraints on the maximum depositional age (Liu et al., 2011).Like controversy on the tectonic setting of the Lüliang Group, debateson the tectonic setting of the Yejishan Group also remain, rangingfrom the continent marginal rift (Geng et al., 2003) to the active conti-nental margin (Liu et al., 2009b, 2012a).

TheHeichashan/Lanhe Groups aremainly distributed in thewesternpart of the complex and unconformably overlie the Jiehekou, Lüliangand Yejishan Groups (Fig. 2). The main lithologic sequences changefrom the meta-conglomerates, quartzites, phyllites and dolomites ofthe Lanhe Group to the meta-conglomerates and quartzites of theHeichashan Group. The similarities of the upper coarse-grained sedi-ment sequence of the Yejishan Group with the Heichashan/LanxianGroup in metamorphic grade and rock assemblage led Liu et al.(2009b) to propose that they formed in a late Paleoproterozoic forelandbasin.

3. Samples and analytical techniques

Twenty-one meta-volcanic samples from the Yejishan Group wereselected for major and trace element analysis. Samples for geochemicalanalyses were collected from the least weathered outcrops. After petro-graphic screening, least altered samples were selected for detailed geo-chemical studies.Major elements weremeasured by X-ray fluorescencespectrometry (XRF, Rigaku-2100) with relative standard deviations lessthan 3%. Rare earth elements and other trace elements were analyzedby inductively coupled plasma mass spectrometry (ICP-MS, TJA-PQ-Excel) at theNational Research Center for Geoanalysis, Beijing. Precisionand accuracy are better than 5% for the majority of trace elements.Geochemical data of meta-volcanic rocks from the Lüliang Group(Du et al., 2012; Liu et al., 2014a; Yu et al., 1997b) and meta-intrusiverocks from the Guandishan TTG gneisses (Du et al., 2012; Liu et al.,2009a) are also used in this study. Whole-rock geochemical data wereprocessed with the “GeoPlot” Excel™ plug-in by Zhou and Li (2006).

Nd isotopic analyses of six meta-volcanic rocks from the YejishanGroup were carried out at the Institute of Geology and Geophysics,Chinese Academy of Sciences, Beijing. Whole rock powders for Nd isoto-pic analyses were dissolved in Savillex Teflon screw-top capsule prior toHF + HNO3 + HClO4 dissolution. Nd was separated using the classicaltwo-step ion exchange chromatographic method and measured using aTriton Plus multi-collector thermal ionization mass spectrometer. TheNd isotopic ratios were corrected for mass fractionation by normalizingto 146Nd/144Nd = 0.7219. Five runs of the JNdi-1 international standardaveraged 143Nd/144Nd = 0.512103 ± 0.000008. 147Sm/144Nd ratioswere calculated from Sm and Nd contents determined by the ICP-MSmethod. The Nd isotopic analysis followed procedures described byLi et al. (2011a, 2012a). Sm–Nd isotopic data of meta-volcanic rocksfrom the Lüliang Group (Liu et al., 2014a; Yu et al., 1998) and meta-intrusive rocks from the Guandishan TTG gneisses (Liu et al., 2009a)are also used in this study. εNd values were calculated from thepresent-day Chondrite Uniform Reservoir (CHUR), assuming 147Sm/144Nd ratio of 0.1967 and 143Nd/144Nd ratio of 0.512638 (DePaolo andWasserburg, 1976).

One amphibolite (12LL18-1) from the Bailongshan Formation of theYejishan Group was selected for zircon U–Pb and Lu–Hf isotopic analy-ses. The fresh portions of whole-rockwere powdered in an agate mill toabout 40–80 mesh and zircons were separated using heavy liquid andmagnetic separation methods. The zircons were hand-picked under abinocular microscope and then mounted into epoxy resin disks, whichwere polished to reveal cross sections of the grains and photographedin both reflected and transmitted light. Cathodoluminescence (CL) im-ages of the zircons were obtained before zircon U–Pb analysis, using aJSM6510 SEM attached with a Gatan CL detector. Zircon U–Pb isotopeanalyses were conducted using a Newwave UP 213 laser ablation sys-tem coupled to a Thermo Finnigan NeptuneMC–ICP-MS at the Instituteof Mineral Resources, Chinese Academy of Geological Sciences, Beijing.The ablation protocol employed a spot diameter of 32 μm at 10 Hz rep-etition rate. Zircon GJ1 was used as the external standard and analyzedtwice every 10 analyses. Detailed descriptions for the analytical proce-dures have been given by Hou et al. (2009). Off-line raw data selection,integration of background and analytical signals, and time-drift correc-tion and quantitative calibration for U–Pb dating were calculated using

Fig. 4. Concordia plot of Sample 12LL18-1 from the Yejishan Group, insets showing theweighted average 207Pb/206Pb age.

108 C. Liu et al. / Lithos 208–209 (2014) 104–117

the ICPMSDataCal 8.4 (Liu et al., 2010). Concordia diagrams andweight-ed mean ages were made using Isoplot/Ex_ver 3.23 (Ludwig, 2003).

After zirconU–Pb analyses, Hf analyseswere alsofinished at the Insti-tute of Mineral Resources, Chinese Academy of Geological Sciences,Beijing, using the method of Hou et al. (2007). Analyses were carriedout in situ with a Newwave UP213 laser-ablation system, attached to aNeptune MC–ICP-MS. All analyses used a beam diameter of 44 μm andenergy density of 15–20 J/cm2. ZirconGJ1was used as the reference stan-dard during our routine analyses,with aweightedmean 176Hf/177Hf ratioof 0.282009± 0.000013 (2σ, n=15), indistinguishable from theweight-ed mean 176Hf/177Hf ratio of 0.282000 ± 0.000005 (2σ) using a solutionanalysis method by Morel et al. (2008). For the calculation of εHf values,we have adopted the present day chondritic 176Hf/177Hf ratio of0.282772 (Blichert-Toft and Albarede, 1997). Depleted mantle modelages (TDM) were calculated based on the measured 176Lu/177Hf ratios,referred to the depleted mantle with present-day 176Hf/177Hf =0.28325 and 176Lu/177Hf = 0.0384 (Griffin et al., 2004).

4. Results

4.1. Zircon U–Pb geochronology

We present U–Pb zircon ages for an amphibolite (12LL18-1) fromthe Bailongshan Formation of the Yejishan Group. The CL images ofrepresentative zircons are shown in Fig. 3 and the U–Pb analyticaldata are presented in Supplementary Table 1 and plotted in Fig. 4.

Sample 12LL18-1 is an amphibolite from the Bailongshan Formationand is composed of plagioclase (~50%)+ amphibole (~45%) andminorapatite, zircon and ilmenite. This sample is originally basaltic, and geo-chemically belongs to calc-alkaline basalts to andesites (SupplementaryTable 3). A total of seventeen U–Pb isotopic analyses were obtained on17 grains from this sample. These zircons have prismatic or roundedshapes and range in size from 124 to 32 μm with length/width ratiosof 2:1 to 1:1. The CL images reveal that most of zircons have oscillatoryor sector zonings with high luminescence rims (Fig. 3), suggesting theirmagmatic origins (Corfu et al., 2003) and subsequent growth. Seven-teen analyses gave a relative wide range of Th/U ratios of 1.64–0.25and the measured 207Pb/206Pb ages vary from 3170 Ma to 2146 Ma. Asshown in Fig. 4, eight analyses of them form a regression line with theupper intercept age of 2188 ± 48 Ma (MSWD = 8), which is similarto the 2210 ± 13 Ma for meta-subvolcanic rocks from the sameFormation (Liu et al., 2012a). We therefore consider that the age of2188±48Mamight represent the time of crystallization of the igneousprotolith. The remaining nine older grains with the ages from 3170 Mato 2298Ma aremost likely xenocrysts thatwere captured during the as-cent of the magma. It is worthy to note that the crystallization ages ofthe meta-volcanics from the Yejishan Group (2210–2188 Ma) is nearlythe same with those of the Chijianling–Guandishan TTG gneiss

Fig. 3. Representative selection of cathodoluminescence (CL) zircon images. Circles (44 anεHf(t) values are also plotted. The scale bar is 100 μm long.

(2182–2151 Ma; Geng et al., 2000; Zhao et al., 2008; Liu et al., 2009a;Du et al., 2012) and meta-igneous rocks from the Lüliang Group(2213–2178 Ma; Du et al., 2012; Liu et al., 2012a; Liu et al., 2014a)dated by zircon U–Pb method.

4.2. Zircon Lu–Hf isotopic results

In situ Lu–Hf isotopic analyses of zircons from Sample 12LL18-1 arelisted in Supplementary Table 2 and shown in Fig. 5. Two groups ofzircons have been recognized from amphibolite sample 12LL18-1,magmatic zircons with old ages (xenocrysts) and magmatic zircons re-cording the crystallization age of the igneous protolith. The xenocrystzircons (2702–2488 Ma) have variable Hf isotopic compositions, with176Hf/177Hf ratios of 0.281161–0.281254, εHf(t) values of −2.9 to+1.7 and TDM values of 3.0–2.8 Ga (Supplementary Table 2 andFig. 5). Results of Hf analyses on magmatic zircons display higherεHf(t) values relative to the xenolithic zircons. All of their εHf(t) valuesare located between the CHUR and DM evolution lines and gaveεHf(t) values of +0.1 to +5.4 and TDM model ages of 2.6 to 2.3 Ga(Supplementary Table 2 and Fig. 5).

4.3. Geochemical characteristics

In the Lüliang Complex, four different ~2.2 Ga igneous rock suites arerecognized based on their geochemical characteristics (Supplementary

d 32 μm) show positions of Hf and U–Pb analytical sites, respectively. 207Pb/206Pb and

Fig. 5. εHf (t) vs. zircon 207Pb/206Pb ages diagram of sample 12LL18-1 from the Yejishan Group. CHUR: Chondrite Uniform Reservoir. DM: DepletedMantle. The fields of Lüliang Group areafter Liu et al. (2014a).

109C. Liu et al. / Lithos 208–209 (2014) 104–117

Table 3). These igneous suites, in decreasing relative abundance, are(1) calc-alkaline basalts and andesites, (2) adakitic rocks, (3) Nb-enriched basalts and andesites and (4) magnesian andesites.

4.3.1. Calc-alkaline basalts and andesitesCalc-alkaline basalts and andesites in the Lüliang Complex are

mainly represented by chlorite–albite schists, metabasite, amphibolitesand amphibole schists, and exposed in the Jinzhouying Formation ofthe Lüliang Group (nine samples) and the Qingyangshuwan andBailongshan Formations of the Yejishan Group (twenty-one samples).These samples plot mostly in the tholeiitic basalt field on theFeO*/MgO vs. SiO2 diagram of Miyashiro (1974; not shown), yet frac-tionated REE patterns (Fig. 6a), high Zr/Y ratios (3.4–10.6) and K2O con-tents (Supplementary Table 3) aremore indicative of calc-alkaline suits.Therefore, they are collectively referred to here as the calc-alkaline suitefor convenience. These rocks appear to form continuous trends on dia-grams of major elements vs. MgO, over the range of 47–57 wt.% SiO2

and Mg# of 32–77 (Supplementary Table 3). The most obvious charac-teristic of the calc-alkaline suit is its similarity to common arc basaltsand andesites. On the REE diagrams, they have light rare earth elements(LREEs) at ~50–180 times chondrite, fractionated LREEs with La/SmCN

ratios of 1.6–3.6, enrichment in LREEs relative to heavy rare earth ele-ments (HREEs) with La/YbCN ratios of 3.0–15.7 and fractionated HREEswith Gd/YbCN ratios of 1.2–2.2 (Fig. 6a). On primitive mantle-normalized spider diagrams, the calc-alkaline rocks have coherentpatterns with: (1) uniformly enriched Th and U over La (Fig. 7a);(2) variable Nb troughs relative to Th and La (Nb/Thpm = 0.12–0.38and Nb/Lapm = 0.25–0.40); and (3) generally negative anomalies atP (P/Ndpm = 0.16–0.73) and Ti (Ti/Smpm = 0.23–1.03).

Whole rock Nd isotopic data for the ~2.2 Ga magmatic rocks in theLüliang Complex are presented in Supplementary Table 4 and Figs. 9and 10a. Initial Nd isotopic ratios and εNd(t) values are calculated att = 2.2 Ga. The calc-alkaline basalts to andesites display εNd(t) valuesof −2.69 to +2.14 and TDM of 2.93 to 2.46 Ga (Supplementary Table 4and Fig. 9).

4.3.2. Adakitic rocksAdakitic rocks in the Lüliang Complex occur within the Guandishan

gneiss (six samples) and consist of gneissic tonalites and granodiorites(Liu et al., 2009a). Like typical adakites in the world (Defant andDrummond, 1990; Martin et al., 2005), they are characterized by highAl2O3 contents (13–19 wt.%) and Na2O/K2O ratios (1.26–2.34), high La(14–70 ppm) but low Yb (0.9–1.6 ppm) contents resulting in extremely

fractionated REE patterns (La/YbCN = 19–51), generally negligible topositive Eu anomalies (Fig. 6b), and positive Sr and Ba but negative Nband Ti anomalies in the spider diagrams (Fig. 7b). They all plot in orvery near to the field of adakites on the Sr/Y vs. Y and La/YbCN vs. YbCNdiagrams (Fig. 8a and b). As a group, the adakitic rocks are characterizedby relatively clustered and near to zero εNd(t) values (−0.59 to +0.90;Fig. 9).

4.3.3. Nb-enriched basalts and andesites (NEBA)The NEBAs have been identified in the Jinzhouying (three samples),

Yuanjiacun (two samples) and Dujiagou (one sample) Formations ofthe LüliangGroup. Collectively, they are characterized by higher absoluteNb contents (7–17 ppm) and Nb/Thpm and Nb/Lapm ratios than mostPhanerozoic oceanic island arc basalts and andesites (Nb b 2 ppm),plotting above the diagonal line on Fig. 8c (Polat and Kerrich, 2001).Compositionally, they vary in the SiO2 contents of 49–54 wt.% and Mg#

of 31–60 and, as a group, possess moderately fractionated REEpatterns (La/YbCN = 3.0–10.2) and weakly negative Eu anomalies(Eu/Eu* = 0.7–0.9; Fig. 6c). They are distinguished from thecalc-alkaline suite by their higher Zr (119–317 ppm) and TiO2

(1.05–2.29 wt.%) contents, and higher Nb/Ta (14.4–19.3) and Nb/U(20.6–23.2) ratios. On the primitive mantle-normalized spider dia-grams, the NEBAs display minor negative or positive anomalies in Ba,Nb, Zr and Ti (Fig. 7c), which are almost identical to those of the Ceno-zoic NEBAs (Aguillón-Robles et al., 2001; Sajona et al., 1996;Wang et al.,2013). The NEBAs display the highest εNd(t) values (+2.50 and+3.02)in the four rock types (Fig. 9).

4.3.4. Magnesian andesites (MA)The Lüliang MAs were found in the Jinzhouying Formation of the

Lüliang Group (three samples) where they coexist with NEBAs. Anorthogneiss sample from the Guandishan gneiss reported by Du et al.(2012) is also compositionally similar to the above MAs, which will bediscussed together. The four samples are characterized by anomalouslyhigh MgO (5.2–12.2 wt.%), Cr (74–1078 ppm) and Ni (35–341 ppm)contents for an andesitic–dacitic range of SiO2. They plot above theline between the normal arc andesites and magnesian andesites(McCarron and Smellie, 1998; Fig. 8d), and thus they are designatedas magnesian andesites. Compared to the calc-alkaline suite, the MAshave less TiO2 at a given value of MgO and more fractionated REE pat-terns (La/YbCN = 5–19; Fig. 6d). Similar to the other igneous suites,the MAs are featured by negative anomalies of Nb, Ta and Ti relativeto neighboring REE on the spider diagrams, whereas the anomalies

Fig. 6. Chondrite-normalized REE pattern of the calc-alkaline basalts and andesites(a), adakitic rocks (b), Nb-enriched basalts and andesites (c) and magnesian andesites(d). Normalizing values after Sun and McDonough (1989).

Fig. 7. Primitive mantle-normalized multi-element spider diagrams of the calc-alkalinebasalts and andesites (a), adakitic rocks (b), Nb-enriched basalts and andesites (c) andmagnesian andesites (d). Normalizing values after Sun and McDonough (1989).

110 C. Liu et al. / Lithos 208–209 (2014) 104–117

increase from theNEBAs throughMAs to adakitic rocks (Fig. 7). TheMAsgave the lowest εNd(t) values of −3.90 to −1.17 and TDM of 2.79 to2.58 Ga (Supplementary Table 4 and Fig. 9). Collectively, the whole-rock Nd isotopic date from the four igneous suites plot collinearlywith an ‘age’ of 2144 ± 430 Ma, and an initial 143Nd/144Nd ratio of0.50981 ± 35 (Fig. 10a).

5. Discussion

5.1. Petrogenesis

5.1.1. Assessing post-magmatic alteration and crustal contaminationGiven that all samples analyzed for this study have witnessed

multi-phase deformation and subgreenschist- to amphibolite-faciesregional metamorphism (Liu et al., 2012a; Trap et al., 2009; Zhaoet al., 2000), it is essential to assess the effects of post-magmatic

Fig. 8. (a) Y vs. Sr/Y diagram (Defant andDrummond, 1993). (b) YbCN vs. La/YbCN diagram (Martin, 1999), thefield for subducted oceanic crust-derived adakites is afterWang et al. (2006).(c) Nb/Lapm vs. Nb/Thpm diagram, the dashed line is after Polat and Kerrich (2001). (d) MgO vs. SiO2 diagram, the dashed line is after McCarron and Smellie (1998). (e) Zr vs. La diagram.(f) Zr vs. Nb diagram.

111C. Liu et al. / Lithos 208–209 (2014) 104–117

alteration on geochemical compositions of these meta-igneous rocksbefore using them to evaluate their petrogenesis and tectonic setting(Polat et al., 2002). It is generally believed that in fine-grained igne-ous rocks the Al, REEs (except Ce and Eu), HFSEs, Y, and Sc are leastsusceptible to post-magmatic alteration and greenschist- toamphibolite-facies metamorphism (Kerrich and Fryer, 1979;Manikyamba et al., 2009).

Following the criteria proposed by Polat and Hofmann (2003), sam-ples having significant carbonate and silica replacement (N2%), highloss on ignitions (LOI, N6 wt.%), or large Ce anomalies (Ce/Ce* N 1.1and b0.9) are considered strongly altered. All of the samples reportedin this study have LOI between 0.17 and 4.65 wt.% and Ce/Ce* ratiosof 0.9–1.1 (except one NEBA sample and one calc-alkaline sample;Supplementary Table 1). Furthermore, good correlations between theZr (an element immobile under most metamorphic conditions) andLa, Nb in each of the four igneous suits (Fig. 5e and f), along withcoherent chondrite-normalized REE and primitive mantle-normalizedHFSE patterns in each of the four igneous suites, endorse limited mobil-ity of these elements. In addition, the 2144 Ma isochron age, similar to

the 2.21–2.18 Ga magmatic zircon crystallization ages, suggests thatthe Sm–Nd system has not been significantly disturbed during post-magmatic alteration.

Significant contamination of the calc-alkaline suite volcanics in theLüliang Complex by continental crust during the magma ascent can beruled out based on the following observations: (1) thepillowed structuresof the meta-basalts in the Yejishan Group and their close spatial associa-tionwith the flysch-type sediments are consistent with an oceanic ratherthat a continental setting (Liu et al., 2009b); (2) the presence of positiveεNd(t) value (+2.14); (3) the lack of correlations between εNd(t) valuesand contents of contamination-sensitive elements or ratios, such as Si,Ni, Th, Zr, La/SmCN, Th/Ce, Nb/La and Nb/Th (not shown; Polat et al.,2011); and (4) no correlation between 147Sm/144Nd and εNd(t), whichargues strongly against crustal contamination (not shown; Vervoort andBlichert-Toft, 1999). Many of the above arguments also apply to theadakitic rocks, NEBAs and MAs. In conclusion, the geochemical and Ndisotopic compositions of the ~2.2 Ga igneous rocks in the LüliangComplex, which are consistent with insignificant interaction with oldercontinent crust during the ascent and have not been significantly

Fig. 9. εNd(t) vs. age diagram of samples from the Lüliang Complex. CHUR: Chondrite UniformReservoir. DM: DepletedMantle. Data sources: lower crustal pyroxenite xenoliths in theNCC(Ying et al., 2010); 2.8 Ga mafic enclaves (Liu et al., 2000).

112 C. Liu et al. / Lithos 208–209 (2014) 104–117

disturbed during post-magmatic alteration and metamorphism, areinterpreted to reflect their near-primary source compositions.

5.1.2. Calc-alkaline basalts and andesitesThe calc-alkaline basalts and andesites have fractionated LREEs,

enrichment in LREEs relative to HREEs, fractionated HREEs (La/SmCN = 1.6–3.6, La/YbCN = 3.0–15.7 and Gd/YbCN = 1.2–2.2; Fig. 6a),and negative anomalies at Nb, Ta, P and Ti (Fig. 7a), characteristic ofconvergent margin and volcanic arc magmas (Perfit et al., 1980;Hawkesworth et al., 1993; Pearce and Peate, 1995). Furthermore, thecalc-alkaline basalts and andesites plot in the mantle sourcemetasomatized by fluid-related subduction field in the (Ta/La)N vs.(Hf/Sm)N diagram (Fig. 10b; LaFlèche et al., 1998). These geochemicalfeatures most likely resulted from the slab dehydration-wedgemelting,when HFSEs are retained in the slab whereas LILEs, Th, U and LREEs areremoved from slab-derived fluids to themantle wedge (McCulloch andGamble, 1991; Pearce and Parkinson, 1993). Furthermore, nearly all thecalc-alkaline samples plot on the spinel-garnet lherzolite (50:50) linewith ~1% partial melting degree, whereas the sample 12LL49-2 fromthe Lüliang Group falls close to the garnet lherzolite line with ~5% de-gree of partial melting (Fig. 10c). On the other way, the calc-alkalinesamples have Nb contents of 2.–13 ppm and Zr/Nb ratios of 15–23,higher than those of N-MORB (2.3 ppm and 11–39; Sun andMcDonough, 1989), and εNd(t) values of −2.69 and +2.14, suggestingthat their mantle source was heterogeneous and generally enrichedrelative to N-MORB.

5.1.3. Adakitic rocks and magnesian andesitesAdakitic rocks are believed to be generated by crustal assimilation

and fractional crystallization (AFC) processes from “normal” arc maficmagmas (Castillo et al., 1999), partial melting of the mafic lower crustunder eclogites-facies conditions (Atherton and Petford, 1993; Chunget al., 2003; Condie, 2005) or young and hot slabmeltingunder eclogitesfacies or garnet bearing amphibolite conditions (Kay et al., 1993; Sternand Kilian, 1996).

In the case of the ~2.2 Ga Lüliang adakitic rocks, an oceanic settinghas been supported by several lines of evidence as we discussed earlierin this study and “E-MORB signatures” of some metabasites from theLüliang Group (Liu et al., 2014a). Such geochemical features provideadditional evidence that the AFC process has not been significant. Forexample, the adakitic rocks display coherent REE and HFSE patternsover a range of absolute abundances, which are clearly different fromthose of the calc-alkaline suit (Figs. 6b and 7b). Moreover, most of

them have relatively low Th/Ce ratios (Supplementary Table 3),suggesting that they are more comparable with slab melting ratherthan partial melting of a thickened crust (Wang et al., 2008). Isotopicevidence also argues against lower crust origin for these adakiticrocks, as they have Nd isotopic compositions distinct from those oflower crustal pyroxenite xenoliths in the NCC (Ying et al., 2010;Fig. 9). In particular, the 2.18–2.17 Ga age of the adakitic rocks is consis-tent with the 2182–2112 Ma subduction-related magmatism in theTNCO (Kröner et al., 2005b; Wang et al., 2010b; Wilde, 2002; Wildeand Zhao, 2005; Zhao et al., 2008). Collectively, these lines of evidencesuggest that the adakitic rocks in the Lüliang Complex were producedby the partial melting of a subducted oceanic crust.

The continuous trends between the Lüliang adakitic rocks and MAson many of the variation diagrams (Fig. 8b and d) provide a strongsupport for the affinity of the adakitic rocks to those related to theslabmelting. The generation of MAs is most likely accounted for by pro-gressive interaction of adakitic melts with a peridotite mantle wedge(Kelemen, 1995; Rapp et al., 1999), which is also against a lower crustalmelting model for the adakitic rocks. Moreover, this model for the MAscan account for their ‘normal’ arc geochemical features, such as fraction-ated REEs and pronounced negative Nb and Ti anomalies (Fig. 7d).

5.1.4. Nb-enriched basalts and andesites (NEBA)Two models have been proposed to explain the origin and distinc-

tive geochemical features of theNEBAs: (1)mixing of anOIB or enrichedmantle with a depleted mantle wedge (Castillo et al., 2002); and(2) a mantle wedge metasomatized by adakitic melts (Defant andKepezhinskas, 2001; Defant et al., 1992). In the case of the LüliangNEBAs, we suggest that the latter mechanism is more possible basedon the following evidences: (1) as discussed above, the continuoustrends between the Lüliang adakitic rocks and MAs provide supportfor the interaction of adakitic melts with mantle peridotite; (2) thepoor correlation between Rb and Nb in the Lüliang NEBAs (Fig. 10d)indicates that the enrichment of Nb was not produced by varyingdegrees of partial melting or source depletion (Wang et al., 2008);(3) the positive correlations between Th, La and Nb (Fig. 10eand f) indicate a mantle source metasomatized by melts carryingHSFEs more easily than hydrous fluids (Keppler, 1996); and (4) theapproximately linear positive correlation between 147Sm/144Nd and143Nd/144Nd for the LüliangNEBAs,MAs and adakitic rocks (Fig. 10a) sug-gests their close relationship in petrogenesis (Polat and Kerrich, 2002).On the otherway, the Lüliang NEBAs do not display correlations betweenTh/Nb, La/Nb and Yb (Fig. 10g and h), which indicates that their Nb

Fig. 10. (a) 143Nd/144Nd vs. 147Sm/144Nd diagram. (b) (Ta/La)N vs. (Hf/Sm)N diagram (after LaFlèche et al., 1998). (c) Sm vs. Sm/Yb diagram (after Peng et al., 2010). (d) Nb vs. Rb diagram.(e) Nb vs. Th diagram. (f) Nb vs. La diagram. (g) Yb vs. Th/Nb diagram. (h) Yb vs. La/Nb diagram.

113C. Liu et al. / Lithos 208–209 (2014) 104–117

enrichments did not result from enrichmentmantle “blobs” as suggestedby Castillo et al. (2002).

5.2. Tectonic implication

5.2.1. Redefinition of the Yejishan GroupOur new and recently published geochronological and geochemical

results have led to a better understanding of the stratigraphic sequencesof the Yejishan Group. These results suggest similarities between the

Qingyangshuwan and Bailongshan Formations of the Yejishan Groupand the Lüliang Group based on the following aspects:

1) They are composed chiefly of meta-clastic rocks and variableamounts of meta-volcanics, of which the latter show typicalsubduction-related geochemical features.

2) The eruption ages of themetabasites from the two groups are nearlycontemporaneous, at 2.21–2.18Ga (Liu et al., 2012a, 2014a; Du et al.,2012; this study), which are almost coeval or slightly older than thesubduction-related 2.18–2.15 Ga Chijianling–Guandishan TTG

114 C. Liu et al. / Lithos 208–209 (2014) 104–117

gneiss in the Lüliang Complex (Du et al., 2012; Geng et al., 2000; Liuet al., 2009a; Zhao et al., 2008).

On the other hand, the stratigraphic and geochronological featuresof the Chengdaogou Formation of the Yejishan Group suggest thatit deposited in a different depositional environment from the lowersequences of the group as evidenced by the following factors:

1) The depositional environment change is supported by the angularunconformity between the Bailongshan and Chengdaogou Forma-tions (Liu et al., 2009b).

2) The Chengdaogou Formation consists mainly of shallow-marine tofluvial facies conglomerates and coarse-grained sandstones, whichare different from the underling deep-marine sedimentations.

3) The maximum depositional age of the Chengdaogou Formations isconstrained at ~1.84 Ga by the youngest detrital zircon age peak(Liu et al., 2011), which overlaps with the timing of the major colli-sional event in the TNCO (Guan et al., 2002; Kröner et al., 2005a,2006; Liu et al., 2006; Wang et al., 2010b; Zhang et al., 2009; Zhaoet al., 2002, 2008) and much younger than the 2.21 Ga and 2.06 Gamaximum depositional ages of the Lüliang Group and theQingyangshuwan Formation of the Yejishan Group, respectively(Liu et al., 2011, 2014a).

On the basis of these data, we agree with the redefinition of theYejishan Group proposed by Liu et al. (2009b, 2011), which suggestedthat the Qingyangshuwan and Bailongshan Formations should beremoved from the Yejishan Group and assigned to the Lüliang Groupand the redefined Yejishan Group could be comparable with theHeichashan/Lanhe Groups.

5.2.2. Constraints on the tectonic evolution of the Trans-North ChinaOrogen

As mentioned above, the 2.2–2.1 Ga geological events are wide-spread across the TNCOandhave important implications on the tectonicevolution of the NCC in the Paleoproterozoic (Du et al., 2010, 2012,2013; Kröner et al., 2005b; Liu et al., 2012a, 2014a; Sun et al., 1990;Wang et al., 2010b; Wilde, 2002; Wilde and Zhao, 2005; Xie et al.,2012; Yang et al., 2011; Zhao et al., 2011). However, controversy still re-mains over the petrogenesis and tectonic setting of the 2.2–2.1 Ga igne-ous rocks. One school of researchers suggested a continental rift basinsetting based on the “A-type” signatures of the Xuting granite in theZanhuang Complex and the Dujiagou feldspar porphyritic rocks in theLüliang Complex (Du et al., 2012; Yang et al., 2011). However, basedon the whole-rock and mineral geochemistry, Liu et al. (2012a, 2014a)and Wang et al. (2010b) proposed that the metabasites of the Lüliangand Yejishan Groups in the Lüliang Complex and the Yanmenguanmafic-ultramafic intrusion in the Hengshan Complex were subduction-related.

In this study, the geochronological and geochemical evidence indi-cates that the subduction of oceanic slab may have been responsiblefor the generation of adakitic rocks, MAs and NEBAs in the earlyPaleoproterozoic Lüliang Complex, similar to such modern rock associ-ations in the Philippines (Sajona et al., 1996), southern Andes (Sternand Kilian, 1996) and central Tibet (Wang et al., 2007, 2008). In thisframework, the adakitic magmas were generated by the partial meltingof a subducted oceanic slab, which reached its solidus temperature dueto the high geothermal gradients in the mantle (Martin, 1999). Theadakitic magmas, along with the fluids released from the slab, reactedwith the mantle wedge peridotites and resulted in the NEBAs withhigher HFSE contents than normal arc basalts (Hollings and Kerrich,2000; Polat and Kerrich, 2002). On the other way, the MAs wereproduced by hybridization of adakiticmagmaswithmantlewedge peri-dotite (Defant and Kepezhinskas, 2001) and calc-alkaline basalt andandesites came from the partial melting of mantle wedge peridotitemetasomatized by the liberated hydrous fluids.

The above discussion and previous studies about the 2.2–2.1 Gaigneous rocks in the Lüliang and Hengshan Complexes indicate theirsignificant connection with the arc-related magmatism of the mantlewedge affected by either partial melting or dehydration of thesubducted oceanic slab (Liu et al., 2012b, 2014a; Wang et al., 2010b,this study). This is consistent with the model that the collision betweenthe Eastern and Western Blocks along the TNCO to form the NCC oc-curred at ~1.85 Ga (Guo et al., 2005; Kröner et al., 2005a, 2005b, 2006;Liu et al., 2006; Wilde, 2002; Zhang et al., 2007, 2009, 2012; Zhaoet al., 2000, 2005).

6. Conclusions

1) The Qingyangshuwan and Bailongshan Formations should be re-moved from the Yejishan Group and assigned to the Lüliang Groupbased on their similar rock assemblages, subduction-relatedgeochemical features of the meta-volcanics and ~2.2 formationages, and thus the redefined Yejishan Group consists only ofcoarse-grained siliciclastic rocks and could be comparable with theHeichashan/Lanhe Groups.

2) Four rocks suites have been identified from the ~2.2 Ga igneous rocksin the Lüliang Complex based on their geochemical characteristics:calc-alkaline basalts and andesites, adakitic rocks, Nb-enriched basaltsand andesites andmagnesian andesites. The calc-alkalinemagmas areindicative of normal arc magmatism generated in response to themantle wedge metasomatized by hydrous fluids. The adakitic rockswere derived from the partial melting of the subducted oceanic slab.The NEBAs originated frommantle wedgemetasomatized by adakiticmelts and the associatedMAswere products of interaction of adakiticmagmas and mantle wedge peridotite.

3) The close spatial and temporal association of theNEBAswith adakiticrocks and MAs is similar to those in many modern subduction-related environments, suggesting that the final collision betweenthe Eastern and Western Blocks along the TNCO must have hap-pened at some time after ~2.2 Ga.

Supplementary data to this article can be found online at http://dx.doi.org/10.1016/j.lithos.2014.08.025.

Acknowledgments

This research was financially funded by the NSFC grants (41372195and 41190075), Hong Kong RGC GRF grants (7060/12P and 7063/13P)and the Basic Outlay of Scientific Research Work from the Ministry ofScience and Technology (No. J1218). We thank Kejun Hou, Guo Chunliand Chaofeng Li for their laboratory assistance. We are also gratefulfor thoughtful and constructive reviews that significantly improvedthe quality of this paper.

References

Aguillón-Robles, A., Caimus, T., Bellon, H., Maury, R.C., Cotton, J., Bourgois, J., Michaud, F.,2001. Late Miocene adakite and Nb enriched basalts from Vizcaino Peninsula,Mexico: indicators of East Pacific Rise subduction below southern Baja California.Geology 29, 531–534.

Atherton, M.P., Petford, N., 1993. Generation of sodium-rich magmas from newlyunderplated basaltic crust. Nature 362, 144–146.

Blichert-Toft, J., Albarede, F., 1997. The Lu–Hf geochemistry of chondrites and the evolu-tion of the mantle-crust system. Earth and Planetary Science Letters 148, 243–258.

Castillo, P.R., Janney, P.E., Solidum, R.U., 1999. Petrology and geochemistry of Camiguinisland, southern Philippines: insights to the source of adakites and other lavas in acomplex arc setting. Contributions to Mineralogy and Petrology 134, 33–51.

Castillo, P.R., Solidum, R.U., Punongbayan, R.S., 2002. Origin of high field strength elementenrichment in the Sulu Arc, southern Philippines, revisited. Geology 30, 707–710.

Chung, S.L., Liu, D.Y., Ji, J.Q., Chu,M.F., Lee, H.Y.,Wen, D.J., Lo, C.H., Lee, T.Y., Qian, Q., Zhang, Q.,2003. Adakites from continental collision zones: melting of thickened lower crustbeneath southern Tibet. Geology 31, 1021–1024.

Condie, K.C., 2005. TTGs and adakites: are they both slab melts? Lithos 80, 33–44.Corfu, F., Hanchar, J.M., Hoskin, P.W.O., Kinny, P., 2003. Atlas of zircon textures. In:

Hanchar, J.M., Hoskin, P.W.O. (Eds.), Zircon: Mineralogical Society of America.Reviews in Mineralogy and Geochemistry 53, pp. 469–500.

115C. Liu et al. / Lithos 208–209 (2014) 104–117

Defant, M.J., Drummond, M.S., 1990. Derivation of some modern arc magmas by meltingof young subducted oceanic lithosphere. Nature 347, 662–665.

Defant, M.J., Drummond, M.S., 1993. Mount St. Helens: potential example of the partialmelting of the subducted lithosphere in a volcanic arc. Geology 21, 547–550.

Defant, M.J., Kepezhinskas, P., 2001. Evidence suggests slab melting in arc magmas. Eos82, 62–69.

Defant, M.J., Jackson, T.E., Drummond, M.S., De Boher, J.Z., Bellon, H., Feigenson, M.D.,Maury, R.C., Stewart, R.H., 1992. The geochemistry of young volcanism throughoutwestern Panama and southeastern Costa Rica: an overview. Journal of the GeologicalSociety, London 149, 569–579.

DePaolo, D.J., Wasserburg, G.J., 1976. Nd isotopic variations and petrogenetic models.Geophysical Research Letters 3, 249–252.

Drummond, M.S., Defant, M.J., Kepezhinskas, P.K., 1996. Petrogenesis of slab-derivedtrondhjemite–tonalite–dacite/adakite magmas. Transactions of the Royal Society ofEdinburgh: Earth Sciences 87, 205–215.

Du, L.L., Yang, C.H., Guo, J.H., Wang,W., Ren, L.D.,Wan, Y.S., Geng, Y.S., 2010. The age of thebase of the Paleoproterozoic Hutuo Group in the Wutai area, North China Craton:SHRIMP zircon U–Pb dating of basaltic andesite. Chinese Science Bulletin 55,1782–1789.

Du, L.L., Yang, C.H., Ren, L.D., Song, H.X., Geng, Y.S., Wan, Y.S., 2012. The 2.2–2.1 Gamagmatic event and its tectonic implication in the Lüliang Mountains, North ChinaCraton. Acta Petrologica Sinica 28, 2751–2769 (in Chinese with English abstract).

Du, L.L., Yang, C.H., Wang, W., Ren, L.D., Wan, Y.S., Wu, J.S., Zhao, L., Song, H.X., Geng, Y.S.,Hou, K.J., 2013. Paleoproterozoic rifting of the North China Craton: geochemical andzircon Hf isotopic evidence from the 2137 Ma Huangjinshan A-type granite porphyryin the Wutai area. Journal of Asian Earth Sciences 72, 190–202.

Faure, M., Trap, P., Lin, W., Monie, P., Bruguier, O., 2007. Polyorogenic evolution of thePaleoproterozoic Trans-North China Belt, new insights from the Lüliangshan–Hengshan–Wutaishan and Fuping massifs. Episodes 30, 1–12.

Geng, Y.S., Wan, Y.S., Shen, Q., Li, H., Zhang, R., 2000. Chronological framework of the earlyPrecambrian important events in the Lüliang Area. Shanxi Province. Acta GeologicaSinica 74, 216–223 (in Chinese with English abstract).

Geng, Y.S., Wan, Y.S., Yang, C.H., 2003. The Palaeoproterozoic rift-type volcanism inLuliang Area, Shanxi Province and its geological significance. Acta Geoscientia Sinica24, 97–104 (in Chinese with English abstract).

Geng, Y.S., Yang, C.H.,Wan, Y.S., 2006. Paleoproterozoic graniticmagmatism in the Luliangarea, North China Craton: constraint from isotopic geochronology. Acta PetrologicaSinica 22, 305–314 (in Chinese with English abstract).

Griffin, W.L., Belousova, E.A., Shee, S.R., Pearson, N.J., O'Reilly, S.Y., 2004. Archean crustalevolution in the northern Yilgam Craton: U–Pb and Hf-isotope evidence from detritalzircons. Precambrian Research 131, 231–282.

Guan, H., Sun, M., Wilde, S.A., Zhou, X.H., Zhai, M.G., 2002. SHRIMP U–Pb zircon geochro-nology of the Fuping Complex: implications for formation and assembly of the NorthChina Craton. Precambrian Research 113, 1–18.

Guo, J.H., O'Brien, P.J., Zhai, M.G., 2002. High-pressure granulites in the Sangan area, NorthChina Craton: metamorphic evolution, P–T paths and geotectonic significance.Journal of Metamorphic Geology 20, 741–756.

Guo, J.H., Sun, M., Zhai, M.G., 2005. Sm-Nd and SHRIMP U–Pb zircon geochronologyof high-pressure granulites in the Sanggan area, North China Craton: timing ofPaleoproterozoic continental collision. Journal of Asian Earth Sciences 24,629–642.

Guo, R.R., Liu, S.W., Santosh, M., Li, Q.G., Bai, X., Wang, W., 2013. Geochemistry, zirconU–Pb geochronology and Lu–Hf isotopes of metavolcanics from eastern Hebei revealNeoarchean subduction tectonics in the North China Craton. Gondwana Research 24,664–686.

Hawkesworth, C.J., Gallagher, K., Hergt, J.M., 1993. Mantle and slab contributions in arcmagmas. Annual Review of Earth and Planetary Sciences 21, 175–204.

Hollings, P., Kerrich, R., 2000. An Archean arc basalt–Nb-enriched basalt-adakiteassociation: the 2.7 Ga confederation assemblage of the Birch–Uchi greenstone belt,Superior Province. Contributions to Mineralogy and Petrology 139, 208–226.

Hou, K.J., Li, Y.H., Zou, T.R., Qu, X.M., Shi, Y.R., Xie, G.Q., 2007. Laser ablation-MC–ICP-MStechnique for Hf isotope microanalysis of zircon and its geological application. ActaPetrologica Sinica 23, 2595–2604 (In Chinese with English abstract).

Hou, K.J., Li, Y.H., Tian, Y.R., 2009. In situ U–Pb zircon dating using LA-MC–ICP-MS. MineralDeposits 28, 481–492 (in Chinese with English abstract).

Kay, S.M., Ramos, V.A., Marquez, M., 1993. Evidence in Cerro Pampa volcanic rocks of slabmelting prior to ridge trench collision in southern South America. Journal of Geology101, 703–714.

Kelemen, P.B., 1995. Genesis of high Mg# andesites and the continental crust. Contribu-tions to Mineralogy and Petrology 120, 1–19.

Keppler, H., 1996. Constraints from partitioning experiments on the composition ofsubduction-zone fluids. Nature 380, 237–240.

Kerrich, R., Fryer, B.J., 1979. Archean precious metal hydrothermal systems Dome MineAbitibi greenstone belt: II REE and oxygen isotope relations. Canadian Journal ofEarth Sciences 16, 440–458.

Kröner, A., Wilde, S.A., Li, J.H., Wang, K.Y., 2005a. Age and evolution of a late Archaean toPaleoproterozoic upper to lower crustal section in the Wutaishan/Hengshan/Fupingterrain of northern China. Journal of Asian Earth Sciences 24, 577–595.

Kröner, A., Wilde, S.A., O'Brien, P.J., Li, J.H., Passchier, C.W., Walte, N.P., Liu, D.Y., 2005b.Field relationships, geochemistry, zircon ages and evolution of a late Archean toPaleoproterozoic lower crustal section in the Hengshan Terrain of Northern China.Acta Geologica Sinica (English Edition) 79, 605–629.

Kröner, A., Wilde, S.A., Zhao, G.C., O'Brien, P.J., Sun, M., Liu, D.Y., Wan, Y.S., Liu, S.W., Guo, J.H.,2006. Zircon geochronology of mafic dykes in the Hengshan Complex of northernChina: evidence for late Paleoproterozoic rifting and subsequent high-pressure eventin the North China Craton. Precambrian Research 146, 45–67.

Kusky, T.M., 2011. Comparison of results of recent seismic profiles with tectonic models ofthe North China craton. Journal of Earth Sciences 22, 250–259.

Kusky, T.M., Li, J.H., 2003. Paleoproterozoic tectonic evolution of the North China Craton.Journal of Asian Earth Sciences 22, 383–397.

LaFlèche, M.R., Camire, G., Jenner, G.A., 1998. Geochemistry of post-Acadian, Carboniferouscontinental intraplate basalts from the Maritimes Basin, Magdalen Islands, Québec,Canada. Chemical Geology 148, 115–136.

Li, S.Z., Zhao, G.C., Sun, M., Wu, F.Y., Liu, J.Z., Hao, D.F., Han, Z.Z., Luo, Y., 2004. Mesozoic,not Paleoproterozoic SHRIMP U–Pb zircon ages of two Liaoji granites, Eastern Block,North China Craton. International Geology Review 46, 162–176.

Li, S.Z., Zhao, G.C., Sun, M., Han, Z.Z., Luo, Y., Hao, D.F., Xia, X.P., 2005. Deformation historyof the Paleoproterozoic Liaohe assemblage in the eastern block of the North ChinaCraton. Journal of Asian Earth Sciences 24, 659–674.

Li, S.Z., Zhao, G.C., Sun, M., Han, Z.Z., Zhao, G.T., Hao, D.F., 2006. Are the South and NorthLiaohe Groups of the North China Craton different exotic terranes? Nd isotope con-straints. Gondwana Research 9, 198–208.

Li, S.Z., Zhao, G.C., Zhang, J., Sun, M., Zhang, G.W., Luo, D., 2010. Deformational history ofthe Hengshan–Wutai–Fuping belt: implications for the evolution of the Trans-NorthChina Orogen. Gondwana Research 18, 611–631.

Li, C.F., Li, X.H., Li, Q.L., Guo, J.H., Li, X.H., 2011a. Directly determining 143Nd/144Nd isotoperatios using thermal ionization mass spectrometry for geological samples withoutseparation of Sm–Nd. Journal of Analytical Atomic Spectrometry 26, 2012–2022.

Li, X.P., Yang, Z.Y., Zhao, G.C., Grapes, R., Guo, J.H., 2011b. Geochronology of khondalite-seriesrocks of the Jining Complex: confirmation of depositional age and tectonometamorphicevolution of the North China craton. International Geology Review 53, 1194–1211.

Li, C.F., Li, X.H., Li, Q.L., Guo, J.H., Li, X.H., Yang, Y.H., 2012a. Rapid and precise determina-tion of Sr and Nd isotopic ratios in geological samples from the same filament loadingby thermal ionizationmass spectrometry employing a single-step separation scheme.Analytica Chimica Acta 727, 54–60.

Li, S.Z., Zhao, G.C., Santosh, M., Liu, X., Lai, L.M., Suo, Y.H., Song, M.C., Wang, P.C., 2012b.Paleoproterozoic structural evolution of the southern segment of the Jiao-Liao-JiBelt, North China Craton. Precambrian Research 200–203, 59–73.

Liu, S.W., Liang, H.H., Zhao, G.C., Hua, Y.G., Jian, A.H., 2000. Isotopic geochronology andgeological events of early Precambrian complexes in Taihangshan. Science in ChinaSeries D 30, 18–24.

Liu, S.W., Pan, Y.M., Li, J.H., Li, Q.G., Zhang, J., 2002. Geological and isotopic geochemicalconstraints on the evolution of the Fuping Complex, North China Craton. PrecambrianResearch 117, 41–56.

Liu, S.W., Pan, Y.M., Xie, Q.L., Zhang, J., Li, Q.G., 2004. Archean geodynamics in the CentralZone, North China Craton: constraints from geochemistry of two contrasting series ofgranitoids in the Fuping and Wutai Complexes. Precambrian Research 130, 229–249.

Liu, S.W., Pan, Y.M., Xie, Q.L., Zhang, J., Li, Q.G., 2005. Geochemistry of the PaleoproterozoicNanying Granitoid Gneisses: constraints on the tectonic setting of the Central Zone,North China Craton. Journal of Asian Earth Sciences 24, 643–658.

Liu, S.W., Zhao, G.C., Wilde, S.A., Shu, G.M., Sun, M., Li, Q.G., Tian, W., Zhang, J., 2006.Th–U–Pb monazite geochronology of the Lüliang and Wutai Complexes: constraintson the tectonothermal evolution of the Trans-North China Orogen. PrecambrianResearch 148, 205–225.

Liu, S.W., Li, Q.G., Liu, C.H., Lu, Y.J., Zhang, F., 2009a. Guandishan granitoids of thePaleoproterozoic Luliang Metamorphic Complex in the Trans-North China Orogen:SHRIMP zircon ages, petrogenesis and tectonic implications. Acta Geologica Sinica-English Edition 83, 580–602.

Liu, S.W., Li, Q.G., Zhang, L.F., 2009b. Geology, geochemistry of metamorphic volcanic rocksuite in Precambrian Yejishan Group, Luliangmountains and its tectonic implications.Acta Petrologica Sinica 25, 547–560 (in Chinese with English abstract).

Liu, Y.S., Hu, Z.C., Zong, K.Q., Gao, C.G., Gao, S., Xu, J., Chen, H.H., 2010. Reappraisement andrefinement of zircon U–Pb isotope and trace element analyses by LA-ICP-MS. ChineseScience Bulletin 55, 1535–1546.

Liu, C.H., Zhao, G.C., Sun, M., Wu, F.Y., Yang, J.H., Yin, C.Q., Leung, Y.H., 2011. U–Pb and Hfisotopic study of detrital zircons from the Yejishan Group of the Lüliang Complex:constraints on the timing of collision between the Eastern and Western Blocks,North China Craton. Sedimentary Geology 236, 129–140.

Liu, S.W., Zhang, J., Li, Q.G., Zhang, L.F., Wang, W., Yang, P.T., 2012a. Geochemistry andU–Pb zircon ages of metamorphic volcanic rocks of the Paleoproterozoic LüliangComplex and constraints on the evolution of the Trans-North China Orogen, NorthChina Craton. Precambrian Research 222–223, 173–190.

Liu, C.H., Zhao, G.C., Liu, F.L., Sun, M., Zhang, J., Yin, C.Q., 2012b. Zircons U–Pb and Lu–Hfisotopic and whole-rock geochemical constraints on the Gantaohe Group in theZanhuang Complex: Implications for the tectonic evolution of the Trans-NorthChina Orogen. Lithos 146–147, 80–92.

Liu, C.H., Zhao, G.C., Liu, F.L., Han, Y.G., 2013a. Nd isotopic and geochemical constraints onthe provenance and tectonic setting of the low-grade meta-sedimentary rocks fromthe Trans-North China Orogen, North China Craton. Journal of Asian Earth Scienceshttp://dx.doi.org/10.1016/j.jseaes.2013.11.007.

Liu, C.H., Liu, F.L., Zhao, G.C., 2013b. Provenance and tectonic setting of the Jiehekou Groupin the Luliang Complex: constraints from zircon U–Pb age and Hf isotopic studies.Acta Petrologica Sinica 29, 517–532 (in Chinese with English abstract).

Liu, J., Liu, F., Ding, Z., Yang, H., Liu, C., Liu, P., Xiao, L., Zhao, L., Geng, J., 2013c. U–Pb datingand Hf isotope study of detrital zircons from the Zhifu Group, Jiaobei Terrane, NorthChina Craton: Provenance and implications for Precambrian crustal growth andrecycling. Precambrian Research 235, 230–250.

Liu, J., Liu, F., Ding, Z., Liu, C., Yang, H., Liu, P., Wang, F., Meng, E., 2013d. The growth,reworking and metamorphism of early Precambrian crust in the Jiaobei terrane, theNorth China Craton: Constraints from U–Th–Pb and Lu–Hf isotopic systematics, andREE concentrations of zircon from Archean granitoid gneisses. Precambrian Research224, 287–303.

116 C. Liu et al. / Lithos 208–209 (2014) 104–117

Liu, P., Liu, F., Liu, C., Wang, F., Liu, J., Yang, H., Cai, J., Shi, J., 2013e. Petrogenesis, P–T–tpath, and tectonic significance of high-pressure mafic granulites from the Jiaobeiterrane, North China Craton. Precambrian Research 233, 237–258.

Liu, C.H., Zhao, G.C., Liu, F.L., Shi, J.R., 2014a. Geochronological and geochemical con-straints on the Lüliang Group in the Lüliang Complex: implications for the tectonicevolution of the Trans-North China Orogen. Lithos http://dx.doi.org/10.1016/j.lithos.2014.04.003.

Liu, F., Liu, P., Wang, F., Liu, J., Meng, E., Cai, J., Shi, J., 2014b. U–Pb dating of zircons fromgranitic leucosomes in migmatites of the Jiaobei Terrane, southwestern Jiao-Liao-JiBelt, North China Craton: Constraints on the timing and nature of partial melting.Precambrian Research 245, 80–99.

Liu, P., Liu, F., Liu, C., Liu, J., Wang, F., Xiao, L., Cai, J., Shi, J., 2014c. Multiple mafic magmaticand high-grade metamorphic events revealed by zircons from meta-mafic rocksin the Daqingshan–Wulashan Complex of the Khondalite Belt, North China Craton.Precambrian Research 246, 334–357.

Lu, S.N., Zhao, G.C., Wang, H.C., Hao, G.J., 2008. Precambrian metamorphic basement andsedimentary cover of the North China Craton: Review. Precambrian Research 160,77–93.

Ludwig, K.R., 2003. User's Manual for Isoplot 3.00: A Geochronological Toolkit forMicrosoft Excel, Special Publication 4a. Berkeley Geochronology Center, Berkeley,California.

Luo, Y., Sun, M., Zhao, G.C., Li, S.Z., Xu, P., Ye, K., Xia, X.P., 2004. LA-ICP-MS U–Pb zirconages of the Liaohe Group in the Eastern Block of the North China Craton: constraintson the evolution of the Jiao-Liao-Ji Belt. Precambrian Research 134, 349–371.

Luo, Y., Sun, M., Zhao, G.C., Ayers, J.C., Li, S.Z., Xia, X.P., Zhang, J.H., 2008. A comparison ofU–Pb and Hf isotopic compositions of detrital zircons from the North and SouthLiaohe Group: constraints on the evolution of the Jiao-Liao-Ji Belt, North ChinaCraton. Precambrian Research 163, 279–306.

Manikyamba, C., Kerrich, R., Khanna, T.C., Satyanarayanan, M., Krishna, A.K., 2009.Enriched and depleted arc basalts, with Mg-andesites and adakites: a potentialpaired arc-back-arc of the 2.6 Ga Hutti greenstone terrane, India. Geochimica etCosmochimica Acta 73, 1711–1736.

Martin, H., 1999. Adakitic magmas: modern analogues of Archaean granitoids. Lithos 46,411–429.

Martin, H., Smithies, R.H., Rapp, R., Moyen, J.F., Champion, D., 2005. An overview ofadakites, tonalite–trondhjemite–granodiorite (TTG) and sanikoid: relationships andsome implications for crustal evolution. Lithos 79, 1–24.

McCarron, J.J., Smellie, J.L., 1998. Tectonic implications of forearc magmatism andgeneration of high-magnesian andesites: Alexander Island, Antarctica. Journal ofthe Geological Society, London 155, 269–280.

McCulloch, M.T., Gamble, A.J., 1991. Geochemical and geodynamical constraints onsubduction zone magmatism. Earth and Planetary Science Letters 102, 358–374.

Miyashiro, A., 1974. Volcanic rock series in island arcs and active continental margins.American Journal of Science 274, 321–355.

Morel, M.L.A., Nebel, O., Nebel-Jacobsen, Y.J., 2008. Hafnium isotope characterizationof the GJ-1 zircon reference material by solution and laser-ablation MC–ICPMS.Chemical Geology 255, 231–235.

Pearce, J.A., Parkinson, I.J., 1993. Trace element models for mantle melting: application tovolcanic arc petrogenesis. Geological Society, London, Special Publications 76,373–403.

Pearce, J.A., Peate, D.W., 1995. Tectonic implications of the composition of volcanic arcmagmas. Annual Review of Earth and Planetary Sciences 23, 251–285.

Peng, P., Zhai, M.G., Zhang, H.F., Guo, J.H., 2005. Geochronological constraints onthe paleoproterozoic evolution of the North China craton: SHRIMP zircon ages ofdifferent types of mafic dikes. International Geology Review 47, 492–508.

Peng, P., Guo, J.H., Zhai, M.G., Bleeker, W., 2010. Paleoproterozoic gabbronoritic and gra-nitic magmatism in the northern margin of the North China Craton: evidence ofcrust–mantle interaction. Precambrian Research 183, 635–659.

Peng, P., Guo, J.H., Zhai, M.G., Windly, B.F., Li, T.S., Liu, F., 2012a. Genesis of the Henglingmagmatic belt in the North China Craton: implications for Paleoproterozoic tectonics.Lithos 148, 27–44.

Peng, T.P., Fan, W.M., Peng, P.X., 2012b. Geochronology and geochemistry of late Archeanadakitic plutons from the Taishan granite–greenstone Terrain: implications for tectonicevolution of the eastern North China Craton. Precambrian Research 208–211, 53–71.

Perfit, M.R., Gust, D.A., Bence, A.E., Arculus, R.J., Taylor, S., 1980. Chemical characteristics ofisland-arc basalts: implications or mantle sources. Chemical Geology 30, 227–256.

Polat, A., Hofmann, A.W., 2003. Alteration and geochemical patterns in the 3.7–3.8 Ga Isuagreenstone belt, west Greenland. Precambrian Research 126, 197–218.

Polat, A., Kerrich, R., 2001. Magnesian andesites, Nb-enriched basalt-andesites, andadakites from late Archean 2.7 Ga Wawa greenstone belts, Superior Province,Canada: implications for late Archean subduction zone petrogenetic processes. Con-tributions to Mineralogy and Petrology 141, 36–52.

Polat, A., Kerrich, R., 2002. Nd-isotope systematics of ~2.7 Ga adakites, magnesian andes-ites, and arc basalts, Superior Province: evidence for shallow crustal recycling atArchean subduction zones. Earth and Planetary Science Letters 202, 345–360.

Polat, A., Hofmann, A.W., Rosing, M., 2002. Boninite-like volcanic rocks in the 3.7–3.8 GaIsua greenstone belt, West Greenland: geochemical evidence for intra-oceanic sub-duction zone processes in the Earth. Chemical Geology 184, 231–254.

Polat, A., Kusky, T.M., Li, J.H., Fryer, B., Kerrich, R., Patrick, K., 2005. Geochemistry ofNeoarchean (ca. 2.55–2.50 Ga) volcanic and ophiolitic rocks in the Wutaishan green-stone belt, central orogenic belt, North China Craton: implications for geodynamic set-ting and continental growth. Geological Society of America Bulletin 117, 1387–1399.

Polat, A., Appel, P.W.U., Fryber, B.J., 2011. An overview of the geochemistry of Eoarcheanto Mesoarchean ultramafic to mafic volcanic rocks, SW Greenland: implications formantle depletion and petrogenetic processes at subduction zones in the earlyEarth. Gondwana Research 20, 255–283.

Qian, J.H., Wei, C.J., Zhou, X.W., Zhang, Y.H., 2013. Metamorphic P–T paths and new zirconU–Pb age data for garnet–mica schist from the Wutai Group, North China Craton.Precambrian Research 233, 282–296.

Rapp, R.P., Shimizu, N., Norman,M.D., Applegate, G.S., 1999. Reaction between slab-derivedmelts and peridotite in the mantle wedge: experimental constraints at 3.8 GPa.Chemical Geology 160, 335–356.

Sajona, F.G., Maury, R.C., Bellon, H., Cotton, J., Defant, M., 1996. High field strength elementenrichment of Pliocene–Pleistocene island arc basalts, Zamboanga Peninsula, westernMindanao (Philippines). Journal of Petrology 37, 693–726.

Santosh, M., 2010. Assembling North China Craton within the Columbia supercontinent:the role of double-sided subduction. Precambrian Research 178, 149–167.

SBGMR, 1989. Regional Geology of Shanxi Province. Geological Publishing House, Beijing(in Chinese with English abstract).

Shchipansky, A.A., Samsonov, A.V., Bibikova, E.V., Babarina, I.I., Konilov, A.N., Krylov, K.A.,Slabunov, A.I., Bogina, M.M., 2004. Boninite hosting partial subduction zone ophiolitesequences from the north Karelian greenstone belt, NE Baltic Shield, Russia. In:Kusky, T.M. (Ed.), Precambrian Ophiolites and Related Rocks. Elsevier, Amsterdam,pp. 425–486.

Stern, C.R., Kilian, R., 1996. Role of the subducted slab, mantle wedge and continentalcrust in the generation of adakites from the Austral Volcanic Zone. Contributions toMineralogy and Petrology 123, 263–281.

Sun, S.S., McDonough, W.F., 1989. Chemical and isotopic systematics of oceanic basalts:implications for mantle composition and processes. In: Saunders, A.D., Norry, M.J.(Eds.), Magmatism in the Ocean Basins. Geological Society London Special Publication42, pp. 313–345.

Sun, D.Z., Hu, W.X., Tang, M., Zhao, F.Q., Condie, K.C., 1990. Origin of Late Archean andEarly Proterozoic rocks and associated mineral deposits from the Zhongtiao Moun-tains, east-central China. Precambrian Research 47, 287–306.

Sun, M., Armstrong, R.L., Lambert, R.St.J., 1992. Petrochemistry and Sr, Pb and Nd isotopicgeochemistry of Early Precambrian rocks, Wutaishan and Taihangshan areas, China.Precambrian Research 56, 1–31.

Tam, P.Y., Zhao, G.C., Liu, F.L., Zhou, X.W., Sun, M., Li, S.Z., 2011. SHRIMP U–Pb zircon agesof high-pressure mafic and pelitic granulites and associated rocks in the Jiaobeimassif: constraints on the metamorphic ages of the Paleoproterozoic Jiao-Liao-JiBelt in the North China Craton. Gondwana Research 19, 150–162.

Tam, P.Y., Zhao, G.C., Sun, M., Li, S.Z., Iizukac, Y., Ma, S.K., yin, C.Q., He, Y.H., Wu, M.L.,2012a. Metamorphic P–T path and tectonic implications of medium-pressure peliticgranulites from the Jiaobei massif in the Jiao-Liao-Ji Belt, North China Craton. Precam-brian Research 220–221, 177–191.

Tam, P.Y., Zhao, G.C., Zhou, X.W., Sun, M., Li, S.Z., Yin, C.Q., Wu, M.L., He, Y.H., 2012b.Metamorphic P–T path and implications of high-pressure pelitic granulites fromthe Jiaobei massif in the Jiao-Liao-Ji Belt, North China Craton. Gondwana Research22, 104–117.

Tam, P.Y., Zhao, G.C., Sun, M., Li, S.Z., Wu, M.L., Yin, C.Q., 2012c. Petrology and metamorphicP–T path of high-pressure mafic granulites from the Jiaobei massif in the Jiao-Liao-JiBelt, North China Craton. Lithos 155, 94–109.

Trap, P., Faure, M., Lin, W., Monié, P., 2007. Late Paleoproterozoic (1900–1800 Ma) nappestacking and polyphase deformation in the Hengshan–Wutaishan area: implicationsfor the understanding of the Trans-North-China Belt, North China Craton. PrecambrianResearch 156, 85–106.

Trap, P., Faure, M., Lin, W., Monie, P., Meffre, S., 2009. The Lüliang Massif: a key areafor the understanding of the Palaeoproterozoic. In: Evans, D., Reddy, S., Collins, A.(Eds.), Palaeoproterozoic Supercontinents and Global Evolution. Geological SocietyLondon Special Publications 323, pp. 99–125.

Trap, P., Faure, M., Lin, W., Breton, N.L., Monie, P., 2012. The Paleoproterozoic evolutionof the Trans-North China Orogen: toward a synthetic tectonic model. PrecambrianResearch 222–223, 191–211.

Vervoort, J.D., Blichert-Toft, J., 1999. Evolution of the depletedmantle: Hf isotope evidencefrom juvenile rocks through time. Geochimica et Cosmochimica Acta 63, 533–556.

Wan, Y.S., Geng, Y.S., Shen, Q.H., Zhang, R.X., 2000. Khondalite series-geocheonology andgeochemistry of the Jiehekou Group in Luliang area, Shanxi province. Acta PetrologicaSinica 16, 49–58 (in Chinese with English abstract).

Wan, Y.S., Song, B., Liu, D.Y., Wilde, S.A., Wu, J.S., Shi, Y.R., Yin, X.Y., Zhou, H.Y., 2006.SHRIMP U–Pb zircon geochronology of Palaeoproterozoic metasedimentary rocks inthe North China Craton: evidence for a major Late Palaeoproterozoic tectonothermalevent. Precambrian Research 149, 249–271.

Wang, K.Y., Li, J.L., Hao, J., Li, J.H., Zhou, S.P., 1996. The Wutaishan mountain belt withinthe Shanxi Province, Northern China: a record of late Archean collision tectonics.Precambrian Research 78, 95–103.

Wang, K.Y., Li, J.L., Hao, J., Li, J.H., Zhou, S.P., 1997. Late Archean mafic-ultramafic rocksfrom the Wuatishan, Shanxi Province: a possible ophiolite melange. Acta PetrologicaSinica 13, 139–151 (in Chinese with English abstract).

Wang, Z.H.,Wilde, S.A., Wang, K.Y., Yu, L.J., 2004. AMORB-arc basalt-adakite association inthe 2.5 GaWutai greenstone belt: late Archean magmatism and crustal growth in theNorth China Craton. Precambrian Research 131, 323–343.

Wang, Q., Xu, J.F., Jian, P., Bao, Z.W., Zhao, Z.H., Li, C.F., Xiong, X.L., Ma, J.L., 2006. Petrogen-esis of adakitic porphyries in an extensional tectonic setting, Dexing, South China:implications for the genesis of porphyry copper mineralization. Journal of Petrology47, 119–144.

Wang, Q., Wyman, D.A., Zhao, Z.H., Xu, J.F., Bai, Z.H., Xiong, X.L., Dai, T.M., Li, C.F., Chu, Z.Y.,2007. Petrogenesis of Carboniferous adakites and Nb-enriched arc basalts in theAlataw area, northern Tianshan Range (western China): implications for Phanerozoiccrustal growth in the Central Asia orogenic belt. Chemical Geology 236, 42–64.

Wang, Q., Wyman, D.A., Xu, J.F., Wan, Y.S., Li, C.F., Zi, F., Jiang, Z.Q., Qiu, H.N., Chu, Z.Y.,Zhao, Z.H., Dong, Y.H., 2008. Triassic Nb-enriched basalts, magnesian andesites, andadakites of the Qiangtang terrane (central Tibet): evidence for metasomatism by

117C. Liu et al. / Lithos 208–209 (2014) 104–117

slab-derived melts in the mantle wedge. Contributions to Mineralogy and Petrology155, 473–490.

Wang, J., Wu, Y.B., Gao, S., Peng, M., Liu, X.C., Zhao, L.S., Zhou, L., Hu, Z.C., Gong, H.J., Liu, Y.S.,2010a. Zircon U–Pb and trace element data from rocks of the Huai'an Complex: newinsights into the late Paleoproterozoic collision between the Eastern and WesternBlocks of the North China Craton. Precambrian Research 178, 59–71.

Wang, Z.H., Wilde, S.A., Wan, J.L., 2010b. Tectonic setting and significance of 2.3–2.1 Gamagmatic events in the Trans-North China Orogen: new constraints from theYanmenguan mafic-ultramafic intrusion in the Hengshan–Wutai–Fuping area.Precambrian Research 178, 27–42.

Wang, F., Li, X.P., Chu, H., Zhao, G.C., 2011. Petrology and metamorphism of khondalitesfrom Jining Complex in the North China Craton. International Geology Review 53,212–229.

Wang, Y.J., Zhang, A.M., Cawood, P.A., Fan, W.M., Xu, J.F., Zhang, G.W., Zhang, Y.Z., 2013.Geochronological, geochemical and Nd–Hf–Os isotopic fingerprinting of an earlyNeoproterozoic arc–back-arc system in South China and its accretionary assemblyalong the margin of Rodinia. Precambrian Research 231, 343–371.

Wang, X., Zhu, W., Ge, R., Luo, M., Zhu, X., Zhang, Q., Wang, L., Ren, X., 2014a. Twoepisodes of Paleoproterozoic metamorphosed mafic dykes in the Luliang Complex:implications for the evolution of the Trans-North China Orogen. PrecambrianResearch 243, 133–148.

Wang, W., Zhai, M., Li, T., Santosh, M., Zhao, L., Wang, H., 2014b. Archean-Paleoproterozoiccrustal evolution in the eastern North China Craton: zircon U–Th–Pb and Lu–Hfevidence from the Jiaobei terrane. Precambrian Research 241, 146–160.

Wang, G.D., Wang, H., Chen, H.X., Lu, J.S., Wu, C.M., 2014c. Metamorphic evolution andzircon U–Pb geochronology of the Mts. Huashan amphibolites: insights into thePalaeoproterozoic amalgamation of the North China Craton. Precambrian Research245, 100–114.

Wilde, S., 2002. SHRIMP U–Pb zircon ages of theWutai Complex. In: Kröner, A., Zhao, G.C.,Wilde, S.A., Zhai, M.G., Passchier, C.W., Sun, M., Guo, J.H., O'Brien, P.J., Walte, N. (Eds.),A Late Archaean to Palaeoproterozoic Lower to Upper Crustal Section in theHengshan–Wutaishan Area of North ChinaGuidebook for Penrose Conference FieldTrip, September 2002. Chinese Academy of Sciences, Beijing, pp. 32–34.

Wilde, S.A., Zhao, G.C., 2005. Archean to Paleoproterozoic evolution of the North ChinaCraton. Journal of Asian Earth Sciences 24, 519–522.

Wilde, S.A., Zhao, G.C., Sun, M., 2002. Development of the North China Craton during theLate Archaean and its final amalgamation at 1.8 Ga; some speculations on its positionwithin a global Palaeoproterozoic Supercontinent. Gondwana Research 5, 85–94.

Xia, X.P., Sun, M., Zhao, G.C., Wu, F.Y., Xu, P., Zhang, J.H., Luo, Y., 2006a. U–Pb and Hfisotopic study of detrital zircons from the Wulashan khondalites: Constraints onthe evolution of the Ordos Terrane, Western Block of the North China Craton. Earthand Planetary Science Letters 241, 581–593.

Xia, X.P., Sun, M., Zhao, G.C., Luo, Y., 2006b. LA-ICP-MS U–Pb geochronology of detritalzircons from the Jining Complex, North China Craton and its tectonic significance.Precambrian Research 144, 199–212.

Xia, X.P., Sun, M., Zhao, G.C., Wu, F.Y., Xu, P., Zhang, J.S., 2008. Paleoproterozoic crustalgrowth events in theWestern Block of the North China Craton: evidence from detritalzircon Hf and whole rock Sr–Nd isotopes of the khondalites in the Jining Complex.American Journal of Science 308, 304–327.

Xia, X.P., Sun, M., Zhao, G.C., Wu, F.Y., Xie, L.W., 2009. U–Pb and Hf isotopic study ofdetrital zircons from the Luliang khondalite, North China Craton, and their tectonicimplications. Geological Magazine 146, 701–716.

Xiao, L.L., Wu, C.M., Zhao, G.C., Guo, J.H., Ren, L.D., 2011. Metamorphic P-T paths of theZanhuang amphibolites and metapelites: constraints on the tectonic evolution ofthe Paleoproterozoic Trans-North China Orogen. International Journal of Earth Sci-ences 100, 717–739.

Xie, H.Q., Liu, D.Y., Yin, X.Y., Zhou, H.Y., Yang, C.H., Du, L.L., Wan, Y.S., 2012. Age and tec-tonic setting of Gantaohe Group: Geology, geochemistry and zircon SHRIMP U–Pbdating. Chinese Science Bulletin 57, 4735–4745.

Yang, C.H., Du, L.L., Ren, L.D., Song, H.X., Wan, Y.S., Xie, H.Q., Liu, Z.X., 2011. The age andpetrogenesis of the Xuting granite in the Zanhuang Complex, Hebei Province: con-straints on the structural evolution of the Trans-North China Orogen, North ChinaCraton. Acta Petrologica Sinica 27, 1003–1016 (in Chinese with English abstract).

Yin, C.Q., Zhao, G.C., Sun, M., Xia, X.P., Wei, C.J., Zhou, X.W., Leung, W.H., 2009. LA-ICP-MSU–Pb zircon ages of the Qianlishan Complex: constrains on the evolution ofthe Khondalite Belt in the Western Block of the North China Craton. PrecambrianResearch 174, 78–94.

Yin, C.Q., Zhao, G.C., Guo, J.H., Sun, M., Zhou, X.W., Zhang, J., Xia, X.P., Liu, C.H., 2011. U–Pband Hf isotopic study of zircons of the Helanshan Complex: constrains on theevolution of the Khondalite Belt in the Western Block of the North China Craton.Lithos 122, 25–38.

Yin, C.Q., Zhao, G.C., Wei, C.J., Sun, M., Guo, J.H., Zhou, X.W., 2014. Metamorphism andpartial melting of high-pressure pelitic granulites from the Qianlishan Complex:

constraints on the tectonic evolution of the Khondalite Belt in the North China Craton.Precambrian Research 242, 172–186.

Ying, J.F., Zhang, H.F., Tang, Y.J., 2010. Lower crustal xenoliths from Junan, Shandongprovince and their bearing on the nature of the lower crust beneath the NorthChina Craton. Lithos 119, 363–376.

Yu, J.H.,Wang, D., Wang, C., 1997a. Ages of the Lüliang Group and its mainmetamorphismin the Lüliang Mountains, Shanxi: evidence from single-grain zircon U–Pb ages.Geological Review 43, 403–408 (in Chinese with English abstract).

Yu, J.H., Wang, D.Z., Wang, C.Y., 1997b. Geochemical characteristics and petrogenesis ofthe Early Proterozoic bimodal volcanic rocks from Lüliang Group, Shanxi Province.Acta Petrologica Sinica 13, 59–70 (in Chinese with English abstract).

Yu, J.H., Wang, D.Z., Geng, J.H., 1998. A Paleoproterozoic A-type rhyolite. Geochimica 27,549–558 (in Chinese with English abstract).

Zhai, M.G., 2004. 2.1–1.7 Ga geological event group and its geotectonic significance. ActaPetrologica Sinica 20, 1343–1354 (in Chinese with English abstract).

Zhai, M.G., 2011. Cratonization and the ancient North China continent: a summary andreview. Science China Earth Sciences 54, 1110–1120.

Zhai, M.G., Peng, P., 2007. Paleoproterozoic events in North China Craton. Acta PetrologicaSinica 23, 2665–2682 (in Chinese with English abstract).

Zhai, M.G., Santosh, M., 2011. The early Precambrian odyssey of North China Craton. Asynoptic overview. Gondwana Research 20, 6–25.

Zhai, M.G., Guo, J.H., Yan, Y.H., 1992. Discovery and preliminary study of the Archeanhigh-pressure granulites in the North China. Science China 12B, 1325–1330 (in Chinesewith English abstract).

Zhai, M.G., Guo, J.H., Li, H.H., Yan, Y.H., Li, Y.G., 1995. Discovery of retrograded eclogites inthe Archaean North China Craton. Chinese Science Bulletin 40, 1590–1594.

Zhai, M.G., Guo, J.H., Liu, W.J., 2005. Neoarchean to Paleoproterozoic continental evolutionand tectonic history of the North China craton. Journal of Asian Earth Sciences 24,547–561.

Zhang, J., Zhao, G.C., Li, S.Z., Sun, M., Liu, S.W., Wilde, S.A., Kröner, A., Yin, C.Q., 2007.Deformation history of the Hengshan Complex: implications for the tectonic evolu-tion of the Trans-North China Orogen. Journal of Structural Geology 29, 933–949.

Zhang, J., Zhao, G.C., Li, S.Z., Sun, M., Liu, S.W., Yin, C.Q., 2009. Deformational history of theFuping Complex and new U–Th–Pb geochronological constraints: implications for thetectonic evolution of the Trans-North China Orogen. Journal of Structural Geology 31,177–193.

Zhang, J., Zhao, G.C., Li, S.Z., Sun, M., Liu, S.W., 2012. Structural and aeromagnetic studiesof the Wutai Complex: implications for the Tectonic Evolution of the Trans-NorthChina Orogen. Precambrian Research 222–223, 212–229.

Zhang, S.B., Tang, J., Zheng, Y.F., 2014a. Contrasting Lu–Hf isotopes in zircon from Precam-brian metamorphic rocks in the Jiaodong Peninsula: constraints on the tectonicsuture between North China and South China. Precambrian Research 245, 29–50.

Zhang, X., Yuan, L., Xue, F., Zhai, M., 2014b. Neoarchean metagabbro and charnockite inthe Yinshan block, western North China Craton: petrogenesis and tectonic implica-tions. Precambrian Research http://dx.doi.org/10.1016/j.precamres.2013.11.003.

Zhao, G.C., 2009. Metamorphic evolution of major tectonic units in the basementof the North China Craton: key issues and discussion. Acta Petrologica Sinica 25,1772–1792.

Zhao, G.C., Cawood, P.A., Wilde, S.A., Lu, L.Z., 2000. Metamorphism of basement rocksin the Central Zone of the North China Craton: implications for Paleoproterozoictectonic evolution. Precambrian Research 103, 55–88.

Zhao, G.C., Cawood, P.A., Wilde, S.A., Lu, L.Z., 2001. High-pressure granulites (retrogradedeclogites) from the Hengshan Complex, North China Craton: petrology and tectonicimplications. Journal of Petrology 42, 1141–1170.

Zhao, G.C., Wilde, S.A., Cawood, Sun M., 2002. SHRIMP U–Pb zircon ages of the FupingComplex: implications for accretion and assembly of the North China Craton.American Journal of Science 302, 191–226.

Zhao, G.C., Sun, M., Wilde, S.A., Li, S.Z., 2005. Late Archean to Paleoproterozoic evolution ofthe North China Craton: key issues revisited. Precambrian Research 136, 177–202.

Zhao, G.C., Wilde, S.A., Sun, M., Li, S.Z., Li, X.P., Zhang, J., 2008. SHRIMP U–Pb zircon ages ofgranitoid rocks in the Luliang Complex: implications for the accretion and evolutionof the Trans-North China Orogen. Precambrian Research 160, 213–226.

Zhao, R.F., Guo, J.H., Peng, P., Liu, F., 2011. 2.1 Ga crustal remelting event in HengshanComplex: evidence from zircon U–Pb dating and Hf-Nd isotopic study on potassicgranites. Acta Petrologica Sinica 27, 1607–1623 (in Chinese with English abstract).

Zhao, G.C., Cawood, P.A., Li, S.Z., Wilde, S.A., Sun, M., Zhang, J., He, Y.H., Yin, C.Q., 2012.Amalgamation of the North China Craton: key issues and discussion. PrecambrianResearch 222–223, 55–76.

Zhou, J., Li, X., 2006. GeoPlot: an Excel VBA program for geochemical data plotting.Computers and Geosciences 32, 554–560.

Zhou, X.W., Zhao, G.C., Wei, C.J., Geng, Y.S., Sun, M., 2008. Metamorphic evolution andTh–U–Pb zircon and monazite geochronology of high-pressure pelitic granulites in theJiaobei massif of the North China Craton. American Journal of Science 308, 328–350.