2. Center for Global Tectonics, China University of Geosciences, Wuhan 430074, China;
3. State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China;
4. State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074, China
Migmatite was coined by Serderholm (1907) to describe a composite rock with hybrid of metamorphic and magmatic features. Partial melting of metamorphic rocks at high-temperature conditions is the fundamental mechanism for migmatization (e.g., Sawyer, 2008a, b; Kriegsman, 2001; Ashworth, 1985; Mehnert, 1968). Crystallization of melt fractions in various degrees as felsic neosomes or leucosome inside paleosomes or mesosomes (non-melted part; i.e., metamorphic protolith) will generate a variety of migmatites (e.g., Sawyer, 2008a, b, 1999). Along with increasing knowledge of this rocks, people have noted some rocks that appear similar outcrop-scale morphology of migmatites turn out not to be the true migmatites but migmatite-like rocks.
The "migmatite-like rock" is referred to such kind of rocks that have light-colored patches, layers, and veins of felsic compositions within a darker host with complex morphologies, produced by other process rather than by partial melting (Sawyer, 2008a). A typical example is the metamorphosed intrusive mingling rocks with their protoliths formed by injection of felsic magma into the preexisting different compositional rocks that finally become enclaves with lobate and cuspate boundaries (e.g., Barbarin, 1988; Mason, 1985). However, their primary structures and intrusive contact boundary can be blurred or eliminated by strong metamorphism and deformation in post-magmatism, generating secondary structures, like deformed structure or typical migmatite-like structures (Sawyer, 2008a; Hopgood, 1999), making people mistake them for diatexite of migmatites (e.g., Koshida et al., 2016; Nehring et al., 2009). The "migmatite-like rock" has magmatic genetic components and thus would have significant implications for magma generation, crustal evolution and shed light on the regional tectonic evolution.
A small portion of basement rocks of the North China Craton, traditionally called Guandi complex in Chinese literatures (Yuan et al., 2016; Liu Y S et al., 2008; Chen and Wang, 2006; Yan et al., 2005; Wang et al., 1990; Liu and Wu, 1987) is sporadically exposed in Zhoukoudian of the Southwest Beijing City. The Guandi complex developed migmatite-like rocks on some outcrops, with felsic gneisses as the host components and minor amphibolites. Up till now, three schools of thought have been brought for the genesis of these rocks: (1) strongly deformed and metamorphosed rocks of Precambrian strata (He, 1936); (2) marginal migmatization of the Mesoproterozoic supracrustal successions during the peak contact metamorphism in Cretaceous (Guo, 1985); (3) regional migmatization of the Precambrian basement in the Neoarchean (Liu B et al., 2008; Zhao, 2003; Wang and Chen, 1996). Furthermore, tectonic settings for the protoliths of these rocks are also poorly understood. In this contribution, a comprehensive study has been carried out on geology, petrography, mineralogy, geochemistry, geochronology and metamorphic P-T conditions of these rocks, attempting to (1) determine the protolith rocks and their formation ages as well as timing of the metamorphism that had undergone; (2) constrain the petrogenesis of protolith rocks; (3) ascertain whether they are true migmatites or migmatite-like rocks; (4) discuss their tectonic implications for evolution of the North China Craton in the transition from Late Neoarchean to Early Paleoproterozoic.1 GEOLOGICAL SETTING 1.1 Geological Background
The North China Craton (NCC) is bounded by the Late Paleozoic Central Asian orogenic belt on the north, the Early Paleozoic Kunlun-Qilian orogenic belt on the west, the Early Paleozoic to Early Mesozoic Qinling-Dabie orogenic belt on the south and the Su-Lu ultrahigh-pressure metamorphic belt on the east (Fig. 1a). It is tectonically divided into the Eastern and Western blocks separated by the Trans-North China Orogen (Fig. 1a; Zhao et al., 2005, 2001). The Eastern Block consists of Archean-Paleoproterozoic basements and Mesoproterozoic- Paleozoic covers. The basement exposes predominantly the Late Mesoarchean-Neoarchean rocks, with minor but the oldest rocks of the NCC formed at ~3.8 Ga (e.g., Zhai, 2014; Zhao and Zhai, 2013; Zhai and Santosh, 2011; Liu et al., 2007; Zhao et al., 2001).
The Late Mesoarchean-Neoarchean rocks in the NCC were mainly formed in ~2.9-2.7 and ~2.6-2.5 Ga periods. The ~2.9- 2.7 Ga rocks are featured in komatiite-basalt-dacite in supra-crustal sequences and dominant of TTGs (tonalite-trondhjemite-granodiorite) with some granitic-granodioritic gneisses (Jia et al., 2016; Wan et al., 2015, 2014b, 2012; Wu et al., 2013; Liu et al., 2009; Jahn et al., 2008). The komatiites are mainly exposed in Taishan complex in West Shandong, the eastern part of NCC (Cheng and Kusky, 2007; Polat et al., 2006; Zhang et al., 1998). Zircon Hf isotopes revealed significant crustal growth during ~2.9-2.7 Ga, which is related to the global growth of Earth's crust recognized from other regions (Wan et al., 2014a). The ~2.6-2.5 Ga rocks were formed as a result of significant crustal reworking, with minor crustal growth at that time in the NCC. The rocks comprises widespread and voluminous magmatic rocks (now mainly orthogneisses of TTG gneisses) with minor gabbros and BIF-bearing supracrustal beds or lenses in the high-grade metamorphic terranes (Wan et al., 2018, 2015, 2014b; Zhou et al., 2018; Li and Wei, 2017; Kusky et al., 2016; Yip, 2016; Geng et al., 2012). The orthogneisses have Hf model ages peaked at ~2.7 Ga (Geng et al., 2012).
Intensive high-grade regional metamorphism occurred over the NCC (e.g., Wang et al., 2014; Wan et al., 2012; Zhai and Santosh, 2011; Jahn et al., 2008), with P-T-t paths showing both clockwise style (e.g., Liu S W et al., 2018; Lu et al., 2017; Liu S J et al., 2015; Zhai et al., 2005) and counter-clockwise patterns (Duan et al., 2017; Wu, 2015; Ge et al., 2003, 1994; Zhao et al., 2001, 1998; Chen et al., 1994; Li, 1993), probably suggesting either continental collision (e.g., Liu et al., 2018; Lu et al., 2017; Kusky et al., 2016; Wang J P et al., 2015; Zhai, 2014), oceanic plate subduction (e.g., Zhou et al., 2018; Bai et al., 2016; Yang et al., 2016; Peng et al., 2015; Diwu et al., 2011), or mantle plume activity (e.g., Li and Wei, 2017; Wang et al., 2014; Zhai and Santosh, 2013, 2011; Zhao and Zhai, 2013; Geng et al., 2012; Yang et al., 2008) tectonic regimes. The metamorphism resulted in local or regional migmatization at different scales (Liu J H et al., 2015; Liu S J et al., 2015; Wang W et al., 2015; Wu et al., 2013; Nutman et al., 2011; Yang et al., 2008).1.2 Guandi Complex
The Guandi complex is located in Zhoukoudian region, about 40 km southwest to Beijing City, in the western margin of the Eastern Block of the NCC (Fig. 1a). The complex dominantly consists of Late-Neoarchean basement rocks spreading sporadically on the south, northeast and east of the Early Cretaceous (~0.13 Ga) Fangshan plutons (Fig. 1b). It is composed of felsic gneiss, leptynite, amphibolite and migmatite (Liu B et al., 2008; Chen and Wang, 2006; Wang et al., 1990; Liu and Wu, 1987; Guo, 1985; He, 1936). Wang et al. (1990) proposed Archaean regional metamorphic origin for these rocks according to petrological and geochemical studies, which are affirmed by the later geochronological researches which yielded 2.37-2.45 Ga for zircons from the orthogneiss, using single-grain zircon Pb-Pb evaporation method (Chen and Wang, 2006). Yan et al. (2005) reported a SHRIMP Ⅱ zircon U-Pb age of 2 521±20 Ma for the biotite-plagioclase gneiss on the southeast of the Fangshan pluton. Liu B et al. (2008) reported two LA-ICP-MS zircon ages of 2 538±35 and 2 548±24 Ma from the amphibolites and associated leucosome, respectively, on the southeast of the Fangshan pluton, which constrained timing of the high-grade metamorphism and anatexis. Wang et al. (2011) applied thermal ionization mass spectrometer (TIMS) to obtain two U-Pb ages of 2 513±14 and 2 534±29 Ma for zircons from orthogneiss on the northeast of the Fangshan pluton. Most recently, Yuan et al. (2016) obtained 2 551±37 Ma for magmatic zircons from amphibolites in the same area as well. All these data suggest that formation of the Guandi complex and the metamorphic-anatectic event occurred at ~2.50-2.55 Ga in the late to the end of Neoarchean.2 OCCURRENCE AND PETROGRAPHY OF THE MIGMATITE-LIKE ROCKS
The studied migmatite-like rocks are exposed in the Guandi complex, on the south of the Fangshan pluton (Fig. 1b). The rocks are lithologically composed of amphibolites and felsic gneisses, with amphibolites occurring in various sized lenses or blocks within the felsic gneisses. The amphibolites display dark green color, foliation structure, and medium-grained prismatic blastic texture and consist of dominant amphibole and plagioclase, without garnet on the outcrops (Figs. 2a, 2b). The felsic gneisses show grey color and clear gneissic structure and occur around the lenticular amphibolites (Figs. 2a, 2b). The rocks have been considered to be migmatites, with the amphibolites as the paleosomes and the felsic gneisses as the neosomes in the previous studies (Liu B et al., 2008; Chen and Wang, 2006; Wang et al., 1990; Liu and Wu, 1987; Guo, 1985; He, 1936). Proportion of the amphibolite show diversity over the Guandi complex, frequently disappearing elsewhere (Figs. 2c-2f); the felsic gneisses appear homogeneity in color, mineral composition, texture and structure as a whole on all outcrops.
The amphibolites consist of dominant amphibole (50%- 80%), plagioclase (20%-25%), with minor quartz (~5%), and accessory minerals of sphene and ilmenite (Figs. 3a, 3b). Three generations of amphiboles were reported by Liu B et al. (2008), with brown-green-colored hornblendic amphibole (Amp1), bluish-green-colored hornblendic amphibole (Amp2) and pale-green colored to colorless actinolite amphibole (Amp3). However, our samples only developed the first and second generation amphiboles in the thin sections (Figs. 3a, 3b). The second-generation amphiboles occur as single grains or reaction rims around the first-generation amphiboles (Figs. 3a, 3b). The plagioclases show anhedral blasts with polysynthetic twins and coexist with the brownish-green first-generation amphiboles (Fig. 3b).
The felsic gneisses consist of predominant plagioclase (55%-60%) and quartz (5%-30%), with minor clinopyroxene (0-10%), hornblende (0-5%), biotite (~4%) and potassium feldspar (< 5%), and/or accessory minerals of apatite, titanite and ilmenite. They can be divided into intermediate and acidic gneisses. The intermediate gneisses or dioritic gneisses (Fig. 2c) has majorly mafic minerals of clinopyroxene, hornblende and biotite and salic minerals of plagioclase, potassium feldspar and minor (~5%) quartz (Fig. 3c). Some of the plagioclases occur as relict subhedral phenocryst (Fig. 3d). The hornblende shows dark green color and occurs as separate matrix grains or rims on the clinopyroxenes. The biotite shows brownish to dark brownish color and also occurs as separate matrix minerals and a collection of tiny flakes along fractures of the hornblendes. The acidic gneisses are mainly composed of quartz, biotite and plagioclase, with minor potassium feldspar and ilmenite (Fig. 3e). The plagioclases show original subhedral crystals with polysynthetic twinning (Fig. 3f). Some plagioclases are locally altered to tiny muscovite assemblage and epidote. The potassium feldspars display anhedral crystals and some of them have been weakly altered to clay minerals.3 ANALYTICAL METHODS
Samples were collected for zircon U-Pb dating and Lu-Hf isotopes analyses, whole-rock major and trace elemental contents analyses and electron microprobe analysis (EMPA) for minerals. Clean and transparent zircon grains were hand-picked under a binocular microscope, and then mounted in epoxy resin, polished down to expose the grain centers. U-Pb isotope and trace element analyses of these zircons were conducted synchronously by LA-ICP-MS at Wuhan Sample Solution Analytical Technology Co., Ltd with an Agilent 7700e ICP-MS instrument and a Geo-Las 2005 laser sampling. Detailed operating conditions for the laser ablation system and the ICP-MS instrument and data reduction were described by Liu Y S et al.(2010, 2008). Zircon 91500 and GJ-1 were respectively used as external and internal standards, with twice every 5 analyses during the whole determination. Concordia diagrams and weighted mean age calculations were made using Isoplot/Exver3 (Ludwig, 2003). The Hf isotopic analysis, using laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS), was carried out on zircon domains near the spots where U-Pb dating had been done at the State Key Laboratory of Geological Processes and Mineral Resources of China University of Geosciences, Wuhan. Spot laser ablation was under a 20 s background acquisitions and 50 s sample data acquisitions, with a beam size of 44 μm, laser pulse frequency of 6 Hz. Detailed analytical procedures were described by Hu et al. (2012). Off-line selection and integration of analyte signals, and mass bias calibrations were performed using ICPMS-Data-Cal (Liu et al., 2010).
Samples for whole-rock analyses were crushed and powdered to 200-mesh in an agate mill before being analyzed by X-ray fluorescence spectrometry at College of Chemistry and Materials Science of China University of Geosciences in Wuhan. The relative standard derivations (RSD) are within 5%. The accuracies are better than 5%-10% for most trace elements. The detailed sample preparation and analytical procedure follow Liu B et al. (2008). The compositions of amphibole and plagioclase were analyzed using a JEOL-JXA-8230 electron microprobe at the Materials Research and Testing Center of Wuhan University of Technology. The microprobe analyses were carried out with an accelerating voltage of 15 kV, a sample current of 2×10-8 nA and a beam diameter of 2 μm. Analytical errors for major and minor element oxides are estimated to be less than 1% and 10%, respectively. The Fe2+ and Fe3+ values of hornblende and biotite were estimated after Droop (1987).4 RESULTS 4.1 Zircon U-Pb Data 4.1.1 Amphibolite (sample CJ14-27)
Zircons from this sample are subhedral, rounded or stubby grains with varying grain sizes of 80-150 μm. Cathodeluminescence (CL) images (Fig. 4a) reveal that some zircons show core-rim structure, with blurry magmatic oscillatory zoning in the cores and dark or bright rims; whereas some zircon grains display cores with blurred irregular banded/sector-zoning, or fir-tree zoning that are commonly considered to be metamorphic origin (Grant et al., 2009; Wu and Zheng, 2004; Corfu et al., 2003; Hoskin and Schaltegger, 2003; Vavra et al., 1999).
Thirteen analyses on the cores (e.g., spots 03, 14 and 15 in Fig. 4a) show consistently Th (> 197 ppm) and U (> 164 ppm) contents and Th/U values (> 0.46). The REE patterns show positive Ce anomalies, moderate negative Eu anomalies and steep HREE patterns (Fig. 5b), further supporting their magmatic origin (Hoskin and Schaltegger, 2003; Rubatto, 2002). These 13 analyses show a linear array and yielded an upper intercept age of 2 553±48 Ma (MSWD=0.71), which is consistent with the concordant 207Pb/206Pb age of 2 560±18 Ma (e.g., spot 10 in Table S1) within error. Thus the 2 560 Ma is interpreted as the crystallization age of the magmatic zircons. The remaining 9 analyses on metamorphic zircons (e.g., spots 07, 09, 12, 13, and 21 in Fig. 4a) form a well-correlated discordia linear array, indicative of different degrees of radiogenic Pb-loss (Corfu et al., 2003), and yielded an upper intercept age of 2 493±16 Ma (MSWD=0.05) (Fig. 5a) which is consistent with the concordant 207Pb/206Pb age of 2 493±29 Ma for spot 07 (Table S1) within error. Thus the age of 2 490 Ma is interpreted to be recrystallization age of the metamorphic zircons and so the regional metamorphic age of the hosted amphibolites. The rare earth elements (REEs) of both the magmatic and metamorphic recrystallization zircons show the same chondrite normalized REE patterns (Fig. 5b), this is probably because the system was closed and few elements had been removed by solid-state replacement or dissolution recrystallization during regional metamorphism (Martin et al., 2008).4.1.2 Felsic gneisses (samples CJ14-12, CJ14-28)
Zircon grains from these samples mainly exhibit prismatic shapes between 100 and 200 μm in length, and show clear core-rim structures (Figs. 4b and 4c). The zircon cores are dark in color, euhedral or subhedral in shape, and have clear and fine oscillatory zoning; the rims are bright and structureless.
Twenty-two out of twenty-nine analyses on the cores for zircons in sample CJ14-12 give Th/U values of 0.42-0.90, suggesting their magmatic origin (Hoskin and Schaltegger, 2003; Rubatto, 2002). Two data which deviate from the dominance of analyses spots are ruled out, the other twenty analyses show discordant but form a well-correlated linear array and yielded an upper intercept age of 2 544±33 Ma (MSWD=0.55) (Fig. 5c), which is consistent with the concordant207Pb/206Pb age of 2 553±34 Ma for spot 25 (Table S1). Therefore, the 2 550 Ma can be considered to be the crystallization age of zircon from the felsic gneiss. The other 7 analyses on the mantle domains or homogeneous bright rims (e.g., spots 16, 19, 21, 25 and 26 in Fig. 4b) define a well-correlated discordia line and yield an upper intercept age of 2 478±45 Ma (MSWD=0.05) (Fig. 5c), in consistence with the weighted mean 207Pb/206Pb age of 2 497±27 Ma (MSWD=0.21). The age of 2 480 Ma is viewed as the timing of the amphibolite-facies metamorphic peak.
Nineteen analyses on domains with oscillatory zoning of 19 zircon cores from sample CJ14-28 (e.g., spots 01 and 03, 06 in Fig. 4c) yielded Th/U values are of 0.52-1.07 and suggest their magmatic origin (Hoskin and Schaltegger, 2003; Rubatto, 2002). When one data with high concordance and evidently younger apparent 207Pb/206Pb age 2 237±28 Ma (spot 02) were ruled out, the rest 18 analyses show different degrees of radiogenic Pb-loss but define a well-correlated discordia line with an upper intercept age of 2 554±18 Ma (MSWD=0.29) (Fig. 5e), consistent with the weighted mean 207Pb/206Pb age of 2 548±26 Ma (MSWD=0.66) of 6 concordant ages (i.e., spots 01, 04, 06, 12, 19 and 26 in Table S1) within error. Therefore, the 2 550 Ma is interpreted as the timing of crystallization age of the zircons. On the other hand, eight analyses were conducted on the homogeneous bright rims (e.g., spot 18 in Fig. 4c) also define a well-correlated discordia line, yielding an upper intercept age of 2 498±47 Ma (MSWD=0.92) (Fig. 5e), which is consistent with the concordant 207Pb/206Pb age of 2 494±29 and 2 494±35 Ma within error (spots 16 and 23 in Table S1). Therefore, the age of 2 490 Ma is interpreted as the timing of recrystallization age of the metamorphic zircons and peak metamorphism of the granitoid.
Both the magmatic and metamorphic zircons from the felsic gneisses mostly show uniform REE patterns with strong positive Ce anomaly, apparent negative Eu anomaly and an strong enrichment of heavy REEs (Figs. 5d, 5f), consistent with those of the igneous zircons (e.g., Rubatto, 2002). As for a few other analyses that have anomalously higher LREE contents with negative Eu anomalies might reflect mobility of incompatible elements (LREE, Th and U) resulting from local recrystallization of the original magmatic zircon (Whitehouse and Kamber, 2003) or likely due to breakdown of LREE bearing minerals contemporaneously with zircon growth (Wu and Zheng, 2004; Whitehouse and Platt, 2003).4.2 Zircon Lu-Hf Isotopes
Thirteen analyses carried out on magmatic zircons from the amphibolite sample (sample CJ14-27) show constant Hf compositions of initial 176Hf/177Hf values (0.281 251-0.281 282), positive initial εHf(t) values (2.6-4.0), with calculation using the formation age (2 560 Ma) of the amphibolite protoliths, corresponding to depleted mantle model ages (TDM) of 2 711-2 763 Ma (Fig. 6). Fourteen spots analyzes on magmatic zircons from the grey gneissic rock (sample CJ14-12) yielded initial 176Hf/177Hf ratios ranging from 0.281 250 to 0.281 312, initial εHf(t) values of 2.8-4.4 (Fig. 6), corresponding to TDM2 ages and two stage depleted mantle model ages (TDM2) of 2 787-2 888 Ma, calculated using the formation age (2 550 Ma) of the gneiss protoliths. Twelve analyses on magmatic zircons show a wide range of initial 176Hf/177Hf values of 0.281 243-0.281 401. The initial εHf(t) values and two stage depleted mantle model ages (TDM2) with the formation age (2 550 Ma) in calculation are 2.8 to 7.1 (Fig. 6), corresponding to TDM2 values of 2 611-2 889 Ma.4.3 Whole-Rock Geochemistry
Whole-rock major and trace elemental data are listed in Table S3, while the values and ratios of major element reported in the text are normalized to 100% on volatile-free basis.
It is generally known that protolith nature of the studied metamorphic rocks should be discriminated before description of their geochemical characteristics. Relict microtextures preserved within and internal structures of zircons from a metamorphosed rocks can provide important clues for its protolith nature (e.g., Sang and Ma, 2012). Although our studied rocks have been strongly metamorphosed and deformed, the large scale homogeneous occurrence and massive structure of the rocks, the euhedral magmatic plagioclase feldspar retained locally within the felsic gneisses (Fig. 3f) all suggest their magmatic protoliths. Furthermore, the zircons from both the amphibolites and felsic gneisses show both oscillatory zoning (Fig. 4) and mono-age value of ~2 550 Ma (Fig. 5) characterized by a single magmatic pulse, rather than multiple-age spectrum for detrital zircons from sedimentary clastic rocks, thus further suggesting magmatic protolith nature of the studied rocks. Geochemical features of a metamorphic rock are also good indicators for protolith nature, and for such study many discrimination diagrams have been constructed and employed to distinguish ortho-metamorphic from para-metamorphic rocks and even distinct lithologies (e.g., Wang et al., 1987). Among the commonly used diagrams, the MgO-CaO-FeO*diagram (Walker et al., 1959) and SiO2-TiO2 diagram (Tarney, 1976) have been frequently taken to distinguish ortho-amphibolite from para-amphibolite and ortho-gneiss from para-gneiss, respectively. As can be seen on the two diagrams, our amphibolites and felsic gneisses are respectively plotted in ortho-amphibolite domain (Fig. 7a) and ortho-gneiss region (Fig. 7b), once again suggesting magmatic protoliths for the studied rocks.4.3.1 Amphibolites
The studied amphibolites contain low to moderate SiO2 (45.7 wt.%-50.2 wt.%), variable Al2O3(11.5 wt.%-16.2 wt.%), moderate CaO (9.45 wt.%-11.1 wt.%) and low TiO2 (0.54 wt.%-0.96 wt.%), but high MgO (9.90 wt.%-13.5 wt.%) and Mg# (Mg#=100×Mg/(Mg+Fe2+)) (63.5-75.3). All samples show subalkaline basaltic affinity (Fig. 8a) and dominantly olivine gabbros on R1-R2 classification diagram (Fig. 8b), respectively. The amphibolites have chondrite-normalized REE patterns characterized by enriched LREEs relative to HREEs, with (La/Yb)N values of 4.59-12.6, and moderate to weakly negatively to non Eu anomalies with δEu=0.57-0.95 (Fig. 9a), characterized by the Archean TH2 type tholeiite (Condie, 1976). The primitive mantle- normalized incompatible trace elements patterns display enrichment of large ion lithophile elements (LILE) and light rare earth elements (LREE), and negative anomaly in some typical high field strength elements (HFSE) of Nb, Ta, and Ti (Fig. 9b).4.3.2 Felsic gneisses
The felsic gneiss samples have wide ranges of SiO2 (54.4 wt.%-70.5 wt.%), covering intermediate to acidic rocks in TAS diagram (Fig. 8a). The rocks has variable and high Al2O3 (15.0 wt.%-20.7 wt. %) and Na2O (4.87 wt.%-6.21 wt.%) but low TiO2 (0.33 wt.%-0.72 wt.%) and P2O5(0.12 wt.%-0.45 wt.%), and high variation of MgO (0.55 wt.%-2.78 wt.%), CaO (1.17 wt.%- 6.69 wt.%) and K2O (0.75 wt.%-3.10 wt.%) concentrations. They also show wide range of Mg# (25-53) and wide-range and high Na2O/K2O values (1.67-8.37). The rocks are plotted mostly in sub-alkaline series domain on TAS diagram (Fig. 8a), with lithology of dominant of quartz monzonite and granulite on R1-R2 diagram (Fig. 8b). The felsic gneiss rocks exhibit moderate variation of total REE contents (44.9 ppm-179 ppm) and highly fractionated REE patterns ((La/Yb)N=17.5-40.1) with evidently positive Eu anomalies (δEu=1.26-1.91) (Fig. 9c). They show low content of Cr (19.0 ppm-26.5 ppm), Ni (6.33 ppm-16 ppm), with only one exception for the intermediate rock sample CJ14-12 which contains Cr of 99.8 ppm and Ni of 48.7 ppm (Table S3). They have high content and highly variable Sr (260 ppm-1 120 ppm) but low Y (3.65 ppm-11.1 ppm) and Yb (0.36 ppm-1.09 ppm) concentrations, with high Sr/Y values of 50.4-139, characterizing high Sr and low Y rock type. The samples display distinct enrichment of large ion lithophile elements (LILE; Rb, Ba, Sr and Pb) whereas negative anomaly of high field strength elements of Nb and Ta (Fig. 9d).4.4 Mineral Chemistry and Estimation of the Peak Metamorphic Conditions 4.4.1 Compositions of amphibole and plagioclase
In order to estimate peak conditions of the ~2.48-2.50 Ga metamorphism, electronic probe analyses were carried out only on both the core and rim domains of the first-generation amphiboles (Amp1) and co-existed plagioclases from five amphibolite samples, and the resultant data for both the amphiboles and plagioclases are listed in Tables S4 and S5, respectively.
The first-generation amphiboles display the same or minor variation compositions for both the core and rim of a given amphibole grain. Analyses on the core show Si=6.43-6.62, CaB= 1.92-2.00, NaB=0.00-0.08, (Ca+Na)B=1.97-2.00, (Na+K)A= 0.56-0.72, Fetot/(Fetot+Mg)=0.37-0.46, Fe3+/(Fe2++Fe3+)=0.00- 0.12; those on the rim show Si=6.51-6.68, CaB=1.90-2.00, NaB=0.00-0.05, (Ca+Na)B=1.96-2.00, (Na+K)A=0.56-0.76, Fetot/(Fetot+Mg)=0.38-0.46, Fe3+/(Fe2++Fe3+)=0.00-0.07. They are pargasite and edenite in Si vs. Mg/(Mg+Fe2+) diagram (Fig. 10) proposed by Leake et al. (1997). It is noteworthy that with one exception (spot 1.2 in sample CJ14-27), the core analyses show Al2O3 content and AlTvalues higher than the rim data, indicating that the cores may record higher pressure and temperature approaching the peak metamorphic conditions, based on a fundamental principle that the AlT content of calcic amphiboles is proportional to metamorphic pressure and temperature increasing (Plyusnina, 1982; Graham, 1974; Hietanen, 1974). The co-existed plagioclase crystals have anorthite contents ranging from 22.87% to 36.58%. Six out of nine selected plagioclase grains show positively zoned anorthite components, with anorthite contents of 24.41%-27.25% in the core increasing to 25.12%-36.58% in the rim, suggesting the prograde process; the other three grains, however, show negatively zoned variations, probably recording the retrograde process. Therefore, the positively zoned anorthite compositions in the rim probably record the compositions representing nearer peak metamorphic conditions.4.4.2 Estimation of P-T conditions
The P-T conditions of metamorphic equilibration for amphibolites can be estimated by application of the amphibole-plagioclase thermometry and related barometry, among which combination of the amphibole-plagioclase thermometry calibrated by Holland and Blundy (1994) and the Al-in-hornblende barometer calibrated by Anderson and Smith (1995) have been frequently used for metamorphic rocks and proven to be well performed (e.g., Li et al., 2017; Xia et al., 2014). However, the plagioclase/amphibole Al-Si partitioning barometer of Molina et al. (2015), based on calibration of the plagioclase/amphibole the Al-Si partitioning barometer by Fershtater (1990) are proven to be more accurate than amphibole-only thermobarometers and can give more reliable estimates.
The rim composition of positively zoned plagioclases and core composition of the co-existed amphibole (e.g., Tables S4 and S5) were chosen for P-T estimations since they are approximating the peak compositions. The P-T estimation for each co-existed Pl-Ampl pair was performed by iterative calculation with the pressure values obtained by the barometer of Anderson and Smith (1995) at various temperature values by thermometers (thermometer Ta and Tb) of Holland and Blundy (1994). Iterative calculation with the pressure values obtained by the barometer of Molina et al. (2015) at various temperature values by Holland and Blundy (1994) thermometers was also performed for comparison. Ta(PAS), Tb(PAS), Ta(PM) and Tb(PM) are temperature values in centigrade; PAS(Ta), PAS(Tb), PM(Ta) and PM(Tb) are pressure values in kbar, but have been changed to GPa in final list in Table S6.
By comparison of calculation results from the thermometer of Anderson and Smith (1995) to those from the hornblende-plagioclase thermometer B (edenite-richterite reaction) of Holland and Blundy (1994), the latter has been considered to give more reliable data because they reproduce more precise temperature results than the thermometer of Anderson and Smith (1995) did. Therefore, the temperature results (Tb) from the calibration of reaction B of Holland and Blundy (1994) and pressure results using temperature parameter by Tb are preferred here. Comparison also shows that the pressure results PAS(Ta) and PAS(Tb) by barometer of Anderson and Smith (1995) are a little lower than those PM(Ta) and PM(Tb) by barometer of Molina et al. (2015), but consistent with each other within their error ranges. Thus we consider the estimation of 0.55-0.9 GPa and 674- 727 ℃ as the best fitting pressure and temperature conditions for the peak metamorphism of the amphibolites from the Guandi complex, Zhoukoudian, Southwest Beijing.5 DISCUSSION 5.1 Timing of Emplacement of Magmatism and Metamorphism
The previously studies suggested that the magmatic protoliths of the felsic gneisses from Guandi complex were formed at 2.53-2.55 Ga (Yuan et al., 2016; Liu B et al., 2008; Yan et al., 2005). Liu B et al. (2008) obtained a metamorphic age of ~2.54 Ga for the metamorphic zircons, the same as those for the magmatic zircons, suggesting that the metamorphism occurred right following the magma emplacement. Our new data reveal that protoliths of the amphibolites and felsic gneisses of the Guandi complex are of magmatic rocks and that emplacement of their precursor magmas occurred at 2.54-2.56 Ga, which is consistent with previous data (Yuan et al., 2016; Liu B et al., 2008; Yan et al., 2005). However, dating of the metamorphic zircons from the three samples all points to that the timing of the peak of the following regional metamorphism occurred during ~2.48-2.50 Ga in this region, rather than ~2.54 Ga estimated by Liu B et al. (2008).5.2 Petrogenesis of the Amphibolites and Felsic Gneisses
The studied amphibolites have moderate LOI values varying from 0.89 wt.% to 1.80 wt.% for 14 samples, with only one sample having a high LOI value of 2.30 wt.% (Table S3), suggesting most of the samples have undergone little influence of later retrograde processes. Since LILE (e.g., K, Rb, Cs and Ba) may become remobilization during the upper amphibolite-facies metamorphic overprint (Humphris and Thompson, 1978), relatively immobile elements such as the high field strength elements (HFSE: Ti, Zr, Y, Nb, Ta, Hf), Th and the rare earth elements (REE) are employed for following discussions of petrogenesis and tectonic implications.5.2.1 Petrogenesis of the amphibolites
It has been known that basaltic magmas are mantle derived and usually chemically interact to some extent with the continental crust during ascent through the crust and/or residence in crustal magma chambers (e.g., Dharma Rao et al., 2004; Ashwal et al., 1986). However, the precursor magmas of the amphibolites of the Guandi complex show negligible crustal assimilation, as evidenced by that they have (1) remarkably lower Th/La values (0.02-0.13) in comparison with 0.36 of the average Archean upper crust (Taylor and McLennan, 1985); (2) low La/Sm values (2.35-4.31, except for one sample with 5.30) in comparison with high La/Sm values (> 4.5), a criteria indicative of the existence of crustal contamination (Shan et al., 2015; Lassiter and Depaolo, 1997); (3) no field evidence about emplacement of the ~2.55 Ga amphibolites into the Guandi complex has been reported and no crustal xenolith has been found within the amphibolites.
The studied amphibolites are characterized by high MgO (9.90 wt.%-13.47 wt.%), Mg#=63-75, with 6 out of 7 samples > 67, and Ni (105 ppm-424 ppm) contents similar to the primitive magma (MgO=8 wt.%-15wt.%, Mg#≥68 and Ni≥250 ppm; see Gill, 2010), with Cr (822 ppm-2 145 ppm) concentrations also approaching the primitive magma (2 520 ppm-2 625 ppm) (McDonough, 2003; Palme and O'Nell, 2003), these make their precursor magma appear to be derived from the asthenosphere mantle, similar to the komatiites or ocean island basalts (OIB). However, the komatiites mostly have depleted LREE patterns, despite that there are some Al-depleted komatiites displaying enriched LREE (or depleted HREE) and low Al2O3 (5.47 wt.%) and Al2O3/TiO2 values of ~5 (e.g., Xie and Kerrich, 1994). Our amphibolites show obvious enriched LREE patterns (Fig. 9a) and their TiO2 contents (0.61 wt.%-1.65 wt.%) are obviously lower than the average TiO2 value of 2.86 wt.% of the OIB that are derived from the asthenospheric mantle, thus also precluding an OIB affinity. Therefore, precursor magma of the amphibolites was not derived from asthenosphere mantle.
The amphibolites show positive zircon εHf(t) values of 2.6-4.0 (Table S2), corresponding to depleted mantle model ages TDM of 2 711-2 763 Ma (Fig. 6), seemingly suggesting a depleted mantle source for their precursor magmas. However, the REE patterns and primitive mantle-normalized trace element patterns show enrichment in LREEs and LILEs and depletion in HFSEs, with negative Nb, Ta, Ti and P anomalies (Fig. 9a), a characteristic feature shared by many arc-related magmas (Sajona et al., 1996; Drummond and Defant, 1990), suggesting the magmas from an enriched lithospheric mantle source due to subduction induced metasomatism (e.g., Pearce, 2008; Pearce and Peate, 1995; Hawkesworth et al., 1993; McCulloch and Gamble, 1991; Saunders et al., 1991) or melts from a depleted mantle source contaminated by crustal materials during magma ascent and emplacement (Yang et al., 2008; Dharma Rao et al., 2004; Ashwal et al., 1986). However, the former explanation is preferred according to statement of negligible crustal assimilation for these amphibolites. Additional supports to this explanation are (1) they have relatively homogeneous Hf isotopic compositions (εHf(t)=2.6-4.0); (2) they plot nearby the enriched mantle source trend in Th/Yb-Nb/Yb diagram (Fig. 11a); (3) they have higher La/Sm and lower Lu/Hf ratios than the primitive mantle (those of which respectively are 1.59 and 0.24 in McDonough and Sun, 1995), as well as the higher values of La/Ta (24.6-75.0) and La/Nb (2.43-6.60) respectively compared to those values of 16.76 and 0.96 for the primitive mantle (Sun and McDonough, 1989); and (4) they have the (Hf/Sm)N values higher than 1 and wide range of (Ta/La)N values between 0.1-1.0 and plotted within or around the melt-related subduction metasomatism domain (Fig. 11b). Thus the precursor magmas of the amphibolites are considered to be sourced from an enriched lithospheric mantle metasomatized by subduction-derived melts or fluids.5.2.2 Petrogenesis of the felsic gneisses
The studied felsic gneisses display high Na2O concentrations (4.87 wt.%-6.21 wt.%) and low to moderate K2O concentrations (0.75 wt.%-3.10 wt.%), high Na2O/K2O (1.67-8.37) and Sr/Y (50.4-139) values and highly fractionated REE patterns (Fig. 9c) with significantly positive Eu anomalies (1.26-1.91), mostly plot into trondhjemite and tonalitic domains (Fig. 12a) (Moyen and Martin, 2012; Martin et al., 2009, 2005). The TTG rocks have been generally considered to be generated by partial melting of hydrated metamorphosed mafic rocks in high pressure conditions, such as eclogite-facies or high-pressure amphibolite- and granulite-facies conditions to stabilize garnet±amphibole±rutile in the residue (Xiong et al., 2009; Martin et al., 2005; Rapp et al., 2003; Foley et al., 2002; Smithies, 2000). It has been proposed that most of Archean TTGs are formed by (1) differentiation of basaltic magmas (Arth, 1979; Barker and Arth, 1976); (2) partial melting of a subducted oceanic slab (Martin et al., 2005; Foley et al., 2002; Martin, 1999; Stern and Kilian, 1996; Drummond and Defant, 1990); (3) partial melting of a tectonically or magmatism- induced thickened lower crust (Condie, 2005; Smithies, 2000; Atherton and Petford, 1993); or (4) partial melting of delaminated mafic crust in an apparently non-subduction related setting (Wang et al., 2007; Bédard, 2006; Xu et al., 2002; Zegers and van Keken, 2001; Kay and Kay, 1993). However, there are several lines of observation to suggest that the TTG type melts did not form by fractional crystallization: (1) The rocks show significantly positive Eu anomalies (1.26-1.91), indicative of no obviously fractional crystallization of plagioclase; (2) the rocks show two partial melting subseries on La/Sm-La variation plotting (not shown); (3) no coeval cumulated ultramafic rocks has been observed in the Guandi complex. These observations rule out the possibility of differentiation for the protolith of the felsic gneisses.
Partial melting of a young and hot subducted oceanic slab will result in TTG melts with higher contents of MgO, Cr (> 36 ppm), Ni (> 24 ppm) and high values of Mg#(> 50) as suggested by Lu et al. (2015) and Martin et al. (2005) because such slab-derived melts will traverse the mantle wedge and interact with the peridotite, leading to significant increase in MgO, Cr and Ni concentrations but decrease in SiO2. Additionally, Mg# is proven to be very sensitive to mantle contribution (Lu et al., 2015), and only small contamination (~10% peridotite) will cause significant (~20%) increase in Mg# (Rapp et al., 1999). On the other hand, partial melting of a delaminated mafic lower crust will also cause increasing in MgO (> 3 wt.%), TiO2 (> 0.9 wt.%) and compatible element contents in TTG rocks due to metasomatism of mantle peridotite (Wang et al., 2007; Xu et al., 2002) and the resultant melts would show similar geochemical characteristics to those from partial melting of the subducting oceanic slab. On contrast to these two processes, partial melting of TTG melts from thickened mafic lower crust of a continental arc is geochemically characterized by low MgO, Ni and Cr contents and Mg#, due to no interaction with the mantle peridotite. Majority of the TTG samples from the Guandi complex, Zhoukoudian area display low MgO (0.55 wt.%-2.78 wt.%), Cr (19.0 ppm-26.5 ppm) and Ni (6.33 ppm-16.0 ppm) and low Mg# values (25.0-53.2) as a whole (Table S3). They mostly plot in the field comparable with those experimentally-derived partial melts from metamorphosed basaltic rocks, and display high-Si and low-Mg geological features (Fig. 12b) (Martin et al., 2005). Furthermore, the TTG gneisses have magmatic zircons showing TDM2 of 2.61-2.89 Ga, suggesting the generation of the basaltic protolith is about 0.1-0.4 Ga older than the formation or emplacement age (~2.54-2.56 Ga) for their precursor melts (e.g., Yuan et al., 2016; Liu B et al., 2008; and this study). Therefore partial melting of thickened lower mafic crust is preferred here than partial melting of delaminated lower crust or subducted hot and young oceanic lithosphere for the precursor magmas of the TTG rocks of the Guandi complex.5.3 Migmatites or Migmatite-Like Rocks?
Migmatites are metamorphic rocks underwent melt-producing reactions during or close to peak metamorphism, usually of upper amphibolite and lower granulite facies (e.g., Vernon and Clarke, 2008; Braun and Kriegsman, 2001). Migmatization provides a possible link between high-grade metamorphism and crustal anatexis according to the "ultra-metamorphism" theory (e.g., Yakymchuk, 2014; Brown, 2007; Hinchey and Carr, 2006; Sawyer, 1998). However, migmatites are not always easily to be distinguished from the high-grade metamorphosed and strongly deformed mafic enclave-rich intrusive rocks.
Felsic gneisses of the migmatite-like rocks of the Guandi complex are compositionally comparable with the Archean TTG suite. As aforementioned, precursor TTG melts of the protoliths of the felsic gneisses were formed by partial melting of metabasites at thickened lower crust during ~2.54-2.56 Ga, coevally with the generation of the basaltic melts at ~2.56 Ga for the amphibolites. The TTG magmas generated from the metabasites within garnet-bearing domains under which pressure and temperature conditions will be as high as 1.0-2.5 GPa and 800-1 000 ℃, according to a recently phase-equilibration modeling in Wei et al. (2017), in order to stabilize garnet the residue sources. Though the studied amphibolites underwent metamorphism with variable pressure conditions of 0.55-0.9 GPa at peak temperature conditions of 674-727 ℃, with the highest pressure conditions approaching the lower pressure limit of > 1.0 Ga for generation precursor magmas of the coeval TTG rocks at ~2.50 Ga (Fig. 5), garnet constitute has not been observed on outcrops (Figs. 2a-2b) nor in thin sections (Figs. 3a-3b) of these mafic metamorphic rocks, thus clearly indicating no genetic relationships between the protoliths of the TTG melts and the formation of the amphibolites. Therefore the association of the felsic gneisses and amphibolites of the Guandi complex in Zhoukoudian area is not of truth migmatites but migmatite-like rocks, but is in fact of a suite of the mingled Na-rich acidic intrusive rocks with mafic enclaves that has undergone amphibolite-facies metamorphism and intensive deformation later at 2.49-2.50 Ga.5.4 Tectonic Setting and Implications 5.4.1 Tectonic setting for the Late Neoarchean magmatism
Our zircon U-Pb ages and whole-rock geochemical data indicate that two constitutes of the migmatite-like rocks recorded a Late Neoarchean (~2.54-2.56 Ga) magmatic intrusion. It is well known that basaltic magmas generate in multiple tectonic settings majorly including subduction-related volcanic arc, within plate and mid-ocean ridge (Pearce, 1996). Subduction-related volcanic arc basalts generally have remarkable enrichment of LILE but depletion of HFSE due to generation from mantle metasomatized by fluids released from the dehydration of a subducting oceanic slab (e.g., Spandler and Pirard, 2013; Pearce, 2008, 1996; Pearce and Peate, 1995; Hawkesworth et al., 1993; McCulloch and Gamble, 1991; Saunders et al., 1991). The normal mid-ocean ridge basalts (N-MORB) generally show depletion in LILE and LREE (e.g., McDonough and Sun, 1995; Sun and McDonough, 1989), and the within plate basalts similar to the oceanic island basalts (OIB) are characterized by high contents of LREE and positive Nb, P, Zr and Hf anomalies (Hollings and Kerrich, 2004). The amphibolites of the Guandi complex have obvious Nb-Ta and Zr-Hf troughs, negative Th anomalies, and positive Rb and Ba anomalies on the primitive mantle normalized spidergram (Fig. 9b), thus showing characteristics of subduction-related arc basalts rather than within plate basalts (WPB). Plots on Ti/100-Zr-3Y diagrams also support this observation (Fig. 14a). Geochemistry-based discrimination on diagrams of MnO×10-P2O5×10-TiO2and Hf/3-Th-Nb/16 (Figs. 14b-14c) further suggest subduction-related arc environments, with minor overlapping with mid-ocean ridge settings, however, plots on the Ti/Sc-Zr diagram preferentially suggests arc environment (Fig. 14d). In addition, these amphibolites have obviously fractionated chondrite-normalized REE patterns, different from those of both MORB and OIB (Figs. 9a-9b) and negative Nb-Ta, Ti, and P anomalies, further suggesting derivation from an enriched mantle source metasomatized at diverse degree by subduction-derived fluids or melts (Fig. 11b) (e.g., Pearce, 2008; Pearce and Peate, 1995; Hawkesworth et al., 1993; McCulloch and Gamble, 1991; Saunders et al., 1991). A previous study by Yuan et al. (2016) on the same age (2 551±37 Ma) amphibolite samples from the Guandi complex, northeast of the Fangshan pluton (Fig. 1b) also showed similar geochemical features and tectonic setting signature to our studied amphibolites (see Figs. 7a, 8a-8b, 9a-9b, 11a-11b, and 14a-14f). Our TTG type gneisses have zircon Hf isotopic TDM ages of 2.61-2.89 Ga, suggesting an ancient continental crust beneath the study area and thus a continental arc setting already existed for generation of precursor magmas of protoliths of the amphibolites and TTG in the end of the Late Neoarchean.5.4.2 Tectonic evolution for NCC during Neoarchean- Early Paleoproterozoic transition
The fundamental geodynamic mechanism for the North China Craton during the Late Neoarchean has been debated and two main stream models of mantle plume (Li and Wei, 2017; Wang et al., 2014; Zhai and Santosh, 2013, 2011; Zhao and Zhai, 2013; Geng et al., 2012; Yang et al., 2008) and plate tectonics (Deng et al., 2018, 2016; Zhou et al., 2018; Kusky et al., 2016; Tang et al., 2016; Wang W et al., 2015; Kusky and Zhai, 2012; Kusky and Li, 2010) were proposed. The mantle plume model is supported by evidences including (1) the exceptionally large exposure of granitoid intrusions that formed over a relatively short time period (2.55-2.50 Ga), without systematic age progression across a ~800 km wide block; (2) affinities of mafic rocks to continental tholeiitic basalts; (3) dominant diaprism-related domal structures; and (4) bimodal volcanic assemblages; (5) short time interval between initial magmatism and regional high-grade metamorphism (Wang et al., 2014; Zhao and Zhai, 2013; Zhao et al., 2001, 1998). The plate tectonic model is suggested by arc magmatism (Zhou et al., 2018; Bai et al., 2016; Yang et al., 2016; Peng et al., 2015; Wang W et al., 2015; Nutman et al., 2011) and arc-continental or continental-continental collision process (Liu et al., 2018; Lu et al., 2017; Chen et al., 2016; Deng et al., 2016; Kusky et al., 2016; Tang et al., 2016; Liu S J et al., 2015; Wang J P et al., 2015). Accordingly, the arc magmatism was established by: (1) the typical island arc-related lithological assemblages, e.g., sanukitoids (Wan et al., 2010; Wang et al., 2009), back arc basin basalt (BABB; Bai et al., 2016), high Mg group of TTG (Wang et al., 2013, 2012; Zhai et al., 2005), meta-volcano-sedimentary rocks (Guo et al., 2015; Peng et al., 2015; Lü et al., 2012; Zhai et al., 1985); (2) geochemical affinities with calc-alkaline plutons in modern magmatic arcs (Zhai, 2014; Wang et al., 2013, 2012; Zhai and Santosh, 2011; Zhai et al., 2005). The collisional process can be evidenced by (1) several geological evidences related to the suture zone of ca. 2.5 Ga arc-continent collisions are recognized (Deng et al., 2016; Tang et al., 2016); (2) Late Neoarchean to Early Paleoproterozoic granulite facies metamorphism with clock-wise P-T-t paths in the Eastern Block of the NCC, indicating subduction-collision tectonics (Liu S W et al., 2018; Lu et al., 2017; Liu S J et al., 2015); (3) post arc-continent collision magmatism such as 2.5-2.4 Ga mafic dykes and 2.50-2.45 Ga potassic granites occurred in the NCC (Deng et al., 2018).
The amphibolites and TTG gneisses of the Guandi complex geochemically suggest a subduction-related continental arc setting for generation of their precursor magma. The metamorphism of the amphibolites at ~2.50 Ga, with pressure conditions of 0.55- 0.90 GPa at peak temperature conditions of ~674-727 ℃ is characterized by medium P/T-type amphibolite-facies metamorphism (Fig. 15) in a collisional tectonics (Chen et al., 2013; Miyashiro, 1973). This metamorphic event occurred coevally with and is comparable to the metamorphism recently reported for the high pressure mafic granulites (2 473±6 Ma; Liu S J et al., 2015) in the Jiaodong Group, eastern Shandong Province and the pelitic granulites (2 497±17 to 2 499±11 Ma; Lu et al., 2017) in the Jidong region, Hebei Province, which are characterized by clockwise P-T-t path pattern which has been usually related to arc-continent collision or continent-continent collision process (Groppo and Rolfo, 2008; Brown, 2007, 1995; Bohlen, 1987). In the meantime, ~2.49 Ga monzogranites and potassium-rich granites, which are considered to be products representing final amalgamation of the continental arc and the ancient continent (e.g., Deng et al., 2018; Wan et al., 2012) have also been observed in the Guandi complex (our unpublished data). Therefore, magmatism and metamorphism of both the amphibolites and felsic gneisses of the Guandi complex might suggest a subduction-collision process, with accretion of continental arc terrane to main continental block during the Late Neoarchean.
Based on a comprehensive study of the basement terranes in the Eastern Block of the NCC, a Late Neoarchean (~2.5-2.6 Ga) intra-oceanic arc system with relict MORB-like basaltic rocks has been recognized bordering the northwestern margin of the continental nucleus (ca. 2.7-3.8 Ga) along the proposed "Wutai-Zunhua-Majuanzi" boundary, extending from northern Liaoning Province, through western Liaoning Province, the Zunhua-Qinglong Block of eastern Hebei Province, northern Hebei Province, and the Huai'an-Xuanhua complexes of northwestern Hebei Province, up to the Wutai complex. The intra-oceanic arc system is characterized by the general lack of ≥2.7 Ga crystalline basement, but it has Late Neoarchean metamorphosed basaltic rocks showing geochemical affinities to MORBs-IATs-CABs. Southeast to the proposed "Wutai-Zunhua-Majuanzi" boundary, an array of coeval high grade metamorphic terranes have been understood parallel to the intra-oceanic arc along the inner margin of the Eastern Block of North China Craton (Fig. 1a; Wang W et al., 2016, 2015 and references therein), from northeast to southwest, including the granite-greenstone belts in southern Jilin regions (SJ in Fig. 1a; Guo B R et al., 2017, 2016), the Qingyuan greenstone in northern Liaoning (QY in Fig. 1a; Wang et al., 2016; Peng et al., 2015), the southern Anshan-Benxi granite-greenstone belt (AB in Fig. 1a; Guo R R et al., 2017), eastern Hebei (EH in Fig. 1a; Bai et al., 2016), Hengshan and Fuping (HS and FP in Fig. 1a; Tang et al., 2016; Liu et al., 2004, 2002). These terranes have zircon Hf isotopic TDM ages of > 2.7 Ga, suggesting their ancient basements (> 2.7 Ga) older than those of the intra-oceanic arc system to the north, and show a giant continental arc system. They have evolved a tectonic setting of active convergent margin, documenting an arc-continental accretion between the arc terranes and the interior Eastern Block of North China Craton (Fig. 1; Wang W et al., 2016, 2015 and references therein). The amphibolites and TTG type of rocks from the Guandi complex formed at ~2.54-2.56 Ga. The amphibolites have affinities dominantly to CABs rather than MORBs and IATs; the TTG-type of rocks have affinities to the low Mg TTGs, which are different from that of the 2.5-2.6 intra-oceanic arc system; both of their zircon Hf isotopes show that the source region are predominantly composed of 2.7-2.9 Ga crusts (Table S2), thus they should be part of the continental arc system rather than of the 2.5-2.6 intra-oceanic arc system. In addition, this TTG-type of rocks formed at ~2.54-2.55 Ga, about 50 Ma earlier than the accretion of the continental arc terrane to the interior Eastern Block of North China Craton. This allow a tectonic model to be proposed with more complex than that proposed by Wang W et al. (2015) in which there was a continental marginal arc developed locally while the parallel pared intra-oceanic and continental arc systems were prevailing regionally (Fig. 16).6 CONCLUSIONS
(1) This study suggests that the "migmatite-like" rocks from the Guandi complex in Zhoukoudian area, southwestern Beijing turn out to be a suite of metamorphosed mingled intrusive rocks composed of TTGs (felsic gneisses) and basaltic components (amphibolites). The two kinds of rocks have their magmatic protoliths formed coevally during ~2.56-2.54 Ga. The precursor magmas of protoliths of the amphibolites were sourced from an enriched lithospheric mantle source metasomatized by subduction-derived melts and/or fluids or in arc-related setting; the TTG magmas were generated by partially melting of hydrated metabasites from thickened lower crust in an arc terrane. Both the lithospheric mantle and the lower crust were formed in 2.7-2.9 Ga, thus probably representing a segment of the giant Neoarchean continental arc system along the inner margin of the interior Eastern Block of the North China Craton.
(2) The TTGs and basic rocks underwent ~2.50-2.49 Ga medium-P/T type upper amphibolite-facies metamorphism, with peak temperature conditions of 674-727 ℃ at pressure conditions of 0.55-0.90 GPa, coevally with metamorphic events occurred in other Archean basement complexes in the Eastern Block of the North China Craton, documenting an accretion or collision tectonic event.
(3) The Guandi complex in Zhoukoudian area, southwestern Beijing probably experienced a complex plate tectonic history with thickening of a continental marginal arc system conducted locally but coevally with the regional development of the pared continental margin arc and intra-oceanic arc along the northwestern border of the interior Eastern Block of North China Craton.ACKNOWLEDGMENTS
This paper is dedicated to the celebration of Prof. Zhendong You's 90th birthday. The corresponding author Neng-Song Chen has been benefited, throughout his life from Prof. Zhendong You who is the supervisor of both the Master's and Doctoral degrees for him, and led him into the world of Metamorphic Geology. We would like to express our great thanks to two anonymous reviewers, whose constructive suggestions and comments have led to great improvements in the quality of this manuscript. We express our gratitude to Prof. Walter Mooney for his helpful suggestion and discussion. Professor Jingbo Liu is specially thanked for his kindly helps with English correction. This study was supported by the National Natural Science Foundation of China (No. 41672060) and the Undergraduate Teaching Projects of China University of Geosciences (Nos. ZL201610 and 2018G36). The final publication is available at Springer via https://doi.org/10.1007/s12583-018-0856-7.
Electronic Supplementary Materials: Supplementary materials (Tables S1-S6) are available in the online version of this article at https://doi.org/10.1007/s12583-018-0856-7.
Anderson, J. L., Smith, D. R., 1995. The Effects of Temperature and fO2 on the Al-in-Hornblende Barometer. American Mineralogist, 80(5/6): 549-559. DOI:10.2138/am-1995-5-614
Arth, J. G., 1979. Some Trace Elements in Trondhjemites-Their Implications to Magma Genesis and Paleotectonic Setting. In: Barker, F., ed., Trondhjemites, Dacites and Related Rocks. Elsevier, Amsterdam. 123-132
Ashwal, L. D., Wooden, J. L., Emslie, R. F., 1986. Sr, Nd and Pb Isotopes in Proterozoic Intrusives Astride the Grenville Front in Labrador:Implications for Crustal Contamination and Basement Mapping. Geochimica et Cosmochimica Acta, 50(12): 2571-2585. DOI:10.1016/0016-7037(86)90211-5
Ashworth, J. R., 1985. Migmatites. In: Ashworth, J. R., ed., Migmatites. Blackie, Glasgow. 302
Atherton, M. P., Petford, N., 1993. Generation of Sodium-Rich Magmas from newly Underplated Basaltic Crust. Nature, 362(6416): 144-146. DOI:10.1038/362144a0
Bai, X., Liu, S. W., Guo, R. R., et al., 2016. A Neoarchean Arc-Back-Arc System in Eastern Hebei, North China Craton:Constraints from Zircon U-Pb-Hf Isotopes and Geochemistry of Dioritic-Tonalitic-Trondhjemitic-Granodioritic (DTTG) Gneisses and Felsic Paragneisses. Precambrian Research, 273: 90-111. DOI:10.1016/j.precamres.2015.12.003
Barbarin, B., 1988. Field Evidence for Successive Mixing and Mingling between the Piolard Diorite and the Saint-Julien-La-Vêtre Monzogranite (Nord-Forez, Massif Central, France). Canadian Journal of Earth Sciences, 25(1): 49-59. DOI:10.1139/e88-005
Barker, F., 1979. Trondhjemite: Definition, Environment and Hypotheses of Origin. In: Barker, F., ed., Trondhjemites, Dacites and Related Rocks. Elsevier, Amsterdam. 1-12
Barker, F., Arth, J. G., 1976. Generation of Trondhjemitic-Tonalitic Liquids and Archean Bimodal Trondhjemite-Basalt Suites. Geology, 4(10): 596-600. DOI:10.1130/0091-7613(1976)4<596:gotlaa>2.0.co;2
Bédard, J. H., 2006. A Catalytic Delamination-Driven Model for Coupled Genesis of Archaean Crust and Sub-Continental Lithospheric Mantle. Geochimica et Cosmochimica Acta, 70(5): 1188-1214. DOI:10.1016/j.gca.2005.11.008
Bohlen, S. R., 1987. Pressure-Temperature-Time Paths and a Tectonic Model for the Evolution of Granulites. The Journal of Geology, 95(5): 617-632. DOI:10.1086/629159
Braun, I., Kriegsman, L. M., 2001. Partial Melting in Crustal Xenoliths and Anatectic Migmatites:A Comparison. Physics and Chemistry of the Earth, Part A:Solid Earth and Geodesy, 26(4/5): 261-266. DOI:10.1016/s1464-1895(01)00054-0
Brown, M., 2007. Metamorphic Conditions in Orogenic Belts:A Record of Secular Change. International Geology Review, 49(3): 193-234. DOI:10.2747/0020-68126.96.36.199
Brown, M., 1995. P-T-t Paths of Orogenic Belts and the Causes of Regional Metamorphism. Geological Society, London, Memoirs, 16: 67-81. DOI:10.1144/GSL.MEM.1995.016.01.09
Chen, H.-X., Wang, H. Y. C., Peng, T., et al., 2016. Petrogenesis and Geochronology of the Neoarchean-Paleoproterozoic Granitoid and Monzonitic Gneisses in the Taihua Complex:Episodic Magmatism of the Southwestern Trans-North China Orogen. Precambrian Research, 287: 31-47. DOI:10.1016/j.precamres.2016.10.014
Chen, N.-S., Liao, F. X., Wang, L., et al., 2013. Late Paleoproterozoic Multiple Metamorphic Events in the Quanji Massif:Links with Tarim and North China Cratons and Implications for Assembly of the Columbia Supercontinent. Precambrian Research, 228: 102-116. DOI:10.1016/j.precamres.2013.01.013
Chen, N.-S., Wang, R. J., Shan, W. R., et al., 1994. Isobaric Cooling P-T-t Path of the Western Section of the Miyun Complex and Its Tectonic Implications. Scientia Geologica Sinica, 29: 354-364.
Chen, N.-S., Wang, F. Z., 2006. Single-Grain Evaporation Zircon Pb-Pb Ages of Guandi Complex, Zhoukoudian Area, Western Hills of Beijing:Archean Genesis and Cratonization Events of the North China Craton. Geological Science and Technology Information, 25: 41-44.
Cheng, S. H., Kusky, T. M., 2007. Komatiites from West Shandong, North China Craton:Implications for Plume Tectonics. Gondwana Research, 12(1/2): 77-83. DOI:10.1016/j.gr.2006.10.015
Condie, K. C., 2005. TTGs and Adakites:Are They both Slab Melts?. Lithos, 80(1/2/3/4): 33-44. DOI:10.1016/j.lithos.2003.11.001
Condie, K. C., 1976. Trace-Element Geochemistry of Archean Greenstone Belts. Earth Science Reviews, 12(4): 393-417. DOI:10.1016/0012-8252(76)90012-X
Corfu, F., Hanchar, J. M., Hoskin, P. W., et al., 2003. Atlas of Zircon Textures. In:Hanchar J. M., Hoskin P. W. O., eds., Zircon. Reviews in Mineralogy and Geochemistry, 53: 469-500. DOI:10.2113/0530469
De la Roche, H., Leterrier, J., Grandclaude, P., et al., 1980. A Classification of Volcanic and Plutonic Rocks Using R1-R2-diagram and Major-Element Analyses-Its Relationships with Current Nomenclature. Chemical Geology, 29(1/2/3/4): 183-210. DOI:10.1016/0009-2541(80)90020-0
Deng, H., Kusky, T. M., Polat, A., et al., 2018. Magmatic Record of Neoarchean Arc-Polarity Reversal from the Dengfeng Segment of the Central Orogenic Belt, North China Craton. Precambrian Research. DOI:10.1016/j.precamres.2018.01.020
Deng, H., Kusky, T. M., Polat, A., et al., 2016. A 2. 5 Ga Fore-Arc Subduction-Accretion Complex in the Dengfeng Granite-Greenstone Belt, Southern North China Craton. Precambrian Research, 275: 241-264. DOI:10.1016/j.precamres.2016.01.024
Diwu, C. R., Sun, Y., Guo, A. L., et al., 2011. Crustal Growth in the North China Craton at~2.5 Ga:Evidence from in situ Zircon U-Pb Ages, Hf Isotopes and Whole-Rock Geochemistry of the Dengfeng Complex. Gondwana Research, 20(1): 149-170. DOI:10.1016/j.gr.2011.01.011
Dharma, Rao C. V., Vijay, Kumar T., Bhaskar, Rao Y. J., 2004. The Pangidi Anorthosite Complex, Eastern Ghats Granulite Belt, India:Mesoproterozoic Sm-Nd Isochron Age and Evidence for Significant Crustal Contamination. Current Science, 89: 1614-1618.
Droop, G. T. R., 1987. A General Equation for Estimating Fe3+ Concentrations in Ferromagnesian Silicates and Oxides from Microprobe Analyses, Using Stoichiometric Criteria. Mineralogical Magazine, 51(361): 431-435. DOI:10.1180/minmag.1987.051.361.10
Drummond, M. S., Defant, M. J., 1990. A Model for Trondhjemite-Tonalite-Dacite Genesis and Crustal Growth via Slab Melting:Archean to Modern Comparisons. Journal of Geophysical Research, 95(B13): 21503. DOI:10.1029/jb095ib13p21503
Duan, Z. Z., Wei, C. J., Rehman, H. U., 2017. Metamorphic Evolution and Zircon Ages of Pelitic Granulites in Eastern Hebei, North China Craton:Insights into the Regional Archean P-T-t History. Precambrian Research, 292: 240-257. DOI:10.1016/j.precamres.2017.02.008
Fershtater, G. B., 1990. Empirical Hornblende-Plagioclase Geobarometer. Geokhimiya, 3: 328-335.
Foley, S., Tiepolo, M., Vannucci, R., 2002. Growth of Early Continental Crust Controlled by Melting of Amphibolite in Subduction Zones. Nature, 417(6891): 837-840. DOI:10.1038/nature00799
Ge, W. C., Zhao, G. C., Sun, D. Y., et al., 2003. Metamorphic P-T Path of the Southern Jilin Complex:Implications for Tectonic Evolution of the Eastern Block of the North China Craton. International Geology Review, 45(11): 1029-1043. DOI:10.2747/0020-68188.8.131.529
Ge, W. C., Sun, D. Y., Wu, F. Y., et al., 1994. The Metamorphic P-T-t Path of Archean Granulites in Huadian Area, Jilin Province. Acta Petrologica et Mineralogica, 13: 232-238.
Geng, Y. S., Du, L. L., Ren, L. D., 2012. Growth and Reworking of the Early Precambrian Continental Crust in the North China Craton:Constraints from Zircon Hf Isotopes. Gondwana Research, 21(2/3): 517-529. DOI:10.1016/j.gr.2011.07.006
Graham, C. M., 1974. Metabasite Amphiboles of the Scottish Dalradian. Contributions to Mineralogy and Petrology, 47(3): 165-185. DOI:10.1007/bf00371537
Grant, M. L., Wilde, S. A., Wu, F. Y., et al., 2009. The Application of Zircon Cathodoluminescence Imaging, Th-U-Pb Chemistry and U-Pb Ages in Interpreting Discrete Magmatic and High-Grade Metamorphic Events in the North China Craton at the Archean/Proterozoic Boundary. Chemical Geology, 261(1/2): 155-171. DOI:10.1016/j.chemgeo.2008.11.002
Gribble, R. F., Stern, R. J., Bloomer, S. H., et al., 1996. MORB Mantle and Subduction Components Interact to Generate Basalts in the Southern Mariana Trough Back-Arc Basin. Geochimica et Cosmochimica Acta, 60(12): 2153-2166. DOI:10.1016/0016-7037(96)00078-6
Gill, R., 2010. Igneous Rocks and Process:A Practical Guide. Wiley-Blackwell: 319.
Groppo, C., Rolfo, F., 2008. Counterclockwise P-T Evolution of the Aghil Range:Metamorphic Record of an Accretionary Melange between Kunlun and Karakorum (SW Sinkiang, China). Lithos, 105(3/4): 365-378. DOI:10.1016/j.lithos.2008.05.011
Guo, B. R., Liu, S. W., Santosh, M., et al., 2017. Neoarchean Arc Magmatism and Crustal Growth in the North-Eastern North China Craton:Evidence from Granitoid Gneisses in the Southern Jilin Province. Precambrian Research, 303: 30-53. DOI:10.1016/j.precamres.2016.12.009
Guo, B. R., Liu, S. W., Zhang, J., et al., 2016. Neoarchean Andean-Type Active Continental Margin in the Northeastern North China Craton:Geochemical and Geochronological Evidence from Metavolcanic Rocks in the Jiapigou Granite-Greenstone Belt, Southern Jilin Province. Precambrian Research, 285: 147-169. DOI:10.1016/j.precamres.2016.09.025
Guo, H. Q., 1985. Petrological Characteristics and Origin of Gneissic Rocks along Northern Flank of Fangshan Intrusion, Beijing. Bulletin of The Institute of Geology Chinese Academy of Geological Science, 13: 105-130.
Guo, R. R., Liu, S. W., Gong, E. P., et al., 2017. Arc-Generated Metavolcanic Rocks in the Anshan-Benxi Greenstone Belt, North China Craton:Constraints from Geochemistry and Zircon U-Pb-Hf Isotopic Systematics. Precambrian Research, 303: 228-250. DOI:10.1016/j.precamres.2017.03.028
Guo, R. R., Liu, S. W., Wyman, D., et al., 2015. Neoarchean Subduction:A Case Study of Arc Volcanic Rocks in Qinglong-Zhuzhangzi Area of the Eastern Hebei Province, North China Craton. Precambrian Research, 264: 36-62. DOI:10.1016/j.precamres.2015.04.007
Hawkesworth, C. J., Gallagher, K., Hergt, J. M., et al., 1993. Mantle and Slab Contributions in Arc Magmas. Annual Review of Earth and Planetary Sciences, 21(1): 175-204. DOI:10.1146/annurev.ea.21.050193.001135
He, Z. L., 1936. The Study of Granitic Intrusion in Western Mountain, Beijing, and Its Metamorphism. Bulletin of the Chinese Academy of Geological Sciences, 5: 24-50.
He, B., Xu, Y. G., Wang, Y. M., et al., 2005. Magmatic Diapir of Fangshan Pluton in the Western Hills, Beijing and Its Geological Significance. Earth Science-Journal of China University of Geosciences, 30(3): 298-308.
Hietanen, A., 1974. Amphibole Pairs, Epidote Minerals, Chlorite, and Plagioclase in Metamorphic Rocks, Northern Sierra Nevada, California. American Mineralogist, 59: 22-40.
Hinchey, A. M., Carr, S. D., 2006. The S-Type Ladybird Leucogranite Suite of Southeastern British Columbia:Geochemical and Isotopic Evidence for a Genetic Link with Migmatite Formation in the North American Basement Gneisses of the Monashee Complex. Lithos, 90(3/4): 223-248. DOI:10.1016/j.lithos.2006.03.003
Holland, T., Blundy, J., 1994. Non-Ideal Interactions in Calcic Amphiboles and Their Bearing on Amphibole-Plagioclase Thermometry. Contributions to Mineralogy and Petrology, 116(4): 433-447. DOI:10.1007/bf00310910
Hollings, P., Kerrich, R., 2004. Geochemical Systematics of Tholeiites from the 2.86 Ga Pickle Crow Assemblage, Northwestern Ontario:Arc Basalts with Positive and Negative Nb-Hf Anomalies.. Precambrian Research, 134(1/2): 1-20. DOI:10.1016/j.precamres.2004.05.009
Hopgood, A. M., 1999. Determination of Structural Successions in Migmatites and Gneisses. Kluwer Academic Publishers: 197-214.
Hoskin, P. W. O., Schaltegger, U., 2003. The Composition of Zircon and Igneous and Metamorphic Petrogenesis. In: Hanchar, J. M., Hoskin, P. W. O., eds., Zircon. Reviews in Mineralogy and Geochemistry, 53(1): 27-62. https://doi.org/10.2113/0530027 http://www.mendeley.com/catalog/composition-zircon-igneous-metamorphic-petrogenesis/
Hu, Z. C., Liu, Y. S., Gao, S., et al., 2012. Improved in Situ Hf Isotope Ratio Analysis of Zircon Using Newly Designed X Skimmer Cone and Jet Sample Cone in Combination with the Addition of Nitrogen by Laser Ablation Multiple Collector ICP-MS. Journal of Analytical Atomic Spectrometry, 27(9): 1391-1399. DOI:10.1039/c2ja30078h
Humphris, S. E., Thompson, G., 1978. Trace Element Mobility during Hydrothermal Alteration of Oceanic Basalts. Geochimica et Cosmochimica Acta, 42(1): 127-136. DOI:10.1016/0016-7037(78)90222-3
Jahn, B. M., Liu, D. H., Wan, Y. S., et al., 2008. Archean Crustal Evolution of the Jiaodong Peninsula, China, as Revealed by Zircon SHRIMP Geochronology, Elemental and Nd-Isotope Geochemistry. American Journal of Science, 308(3): 232-269. DOI:10.2475/03.2008.03
Jia, X. L., Zhu, X. Y., Zhai, M. G., et al., 2016. Late Mesoarchean Crust Growth Event:Evidence from the ca.2.8 Ga Granodioritic Gneisses of the Xiaoqinling Area, Southern North China Craton. Science Bulletin, 61(12): 974-990. DOI:10.1007/s11434-016-1094-y
Kay, R. W., Kay, S. M., 1993. Delamination and Delamination Magmatism. Tectonophysics, 219(1/2/3): 177-189. DOI:10.1016/0040-1951(93)90295-u
Koshida, K., Ishikawa, A., Iwamori, H., et al., 2016. Petrology and Geochemistry of Mafic Rocks in the Acasta Gneiss Complex:Implications for the Oldest Mafic Rocks and Their Origin. Precambrian Research, 283: 190-207. DOI:10.1016/j.precamres.2016.07.004
Kriegsman, L. M., 2001. Partial Melting, Partial Melt Extraction and Partial Back Reaction in Anatectic Migmatites. Lithos, 56(1): 75-96. DOI:10.1016/s0024-4937(00)00060-8
Kusky, T. M., Polat, A., Windley, B. F., et al., 2016. Insights into the Tectonic Evolution of the North China Craton through Comparative Tectonic Analysis:A Record of Outward Growth of Precambrian Continents. Earth-Science Reviews, 162: 387-432. DOI:10.1016/j.earscirev.2016.09.002
La Flèche, M. R., Camiré, G., Jenner, G. A., 1998. Geochemistry of Post-Acadian, Carboniferous Continental Intraplate Basalts from the Maritimes Basin, Magdalen Islands, Québec, Canada. Chemical Geology, 148(3/4): 115-136. DOI:10.1016/s0009-2541(98)00002-3
Lassiter, J. C., Depaolo, D. J., 1997. Plume-Lithosphere Interaction in the Generation of Continental and Oceanic Flood Basalts: Chemical and Isotope Constraints. In: Mahoney, J. J., Coffin, M. F., eds., Large Igneous Provinces: Continental, Oceanic, and Planetary Flood Volcanism. American Geophysical Union, Washington, DC. 335-355 http://adsabs.harvard.edu/abs/1997gms...100..335l
Leake, B. E., Woolley, A. R., Arps, C. E. S., et al., 1997. Nomenclature of Amphiboles Report of the Subcommittee on Amphiboles of the International Mineralogical Association Commission on New Minerals and Mineral Names. European Journal of Mineralogy, 9(3): 623-651. DOI:10.1127/ejm/9/3/0623
Li, Y. L., Brouwer, F. M., Xiao, W. J., et al., 2017. Subduction-Related Metasomatic Mantle Source in the Eastern Central Asian Orogenic Belt:Evidence from Amphibolites in the Xilingol Complex, Inner Mongolia, China. Gondwana Research, 43: 193-212. DOI:10.1016/j.gr.2015.11.015
Li, Z., Wei, C. J., 2017. Two Types of Neoarchean Basalts from Qingyuan Greenstone Belt, North China Craton:Petrogenesis and Tectonic Implications. Precambrian Research, 292: 175-193. DOI:10.1016/j.precamres.2017.01.014
Li, Z. L., 1993. Metamorphic P-T-t Path of the Archaean Rocks in the Eastern Shandong Province and Its Implications. Shandong Geology, 9: 31-41.
Liu, B., Jin, B., Zhang, L., et al., 2008. Zircon LA-ICP-MS U-Pb Dating of Metamorphism and Anatexis of the Guandi Complex, Zhoukoudian Area, Beijing. Geological Science and Technology Information, 27: 37-42.
Liu, D. Y., Wilde, S. A., Wan, Y. S., et al., 2009. Combined U-Pb, Hafnium and Oxygen Isotope Analysis of Zircons from Meta-Igneous Rocks in the Southern North China Craton Reveal Multiple Events in the Late Mesoarchean-Early Neoarchean. Chemical Geology, 261(1/2): 140-154. DOI:10.1016/j.chemgeo.2008.10.041
Liu, G. H., Wu, J. S., 1987. Metamorphic Zones of the Fangshan Area in Beijing. Bulletin of the Chinese Academy of Geological Sciences, 16: 113-137.
Liu, J. H., Liu, F. L., Ding, Z. J., et al., 2015. Early Precambrian Major Magmatic Events, and Growth and Evolution of Continental Crust in the Jiaobei Terrane, North China Craton. Acta Petrologica Sinica, 31: 2942-2958.
Liu, S. J., Jahn, B. M., Wan, Y. S., et al., 2015. Neoarchean to Paleoproterozoic High-Pressure Mafic Granulite from the Jiaodong Terrain, North China Craton:Petrology, Zircon Age Determination and Geological Implications. Gondwana Research, 28(2): 493-508. DOI:10.1016/j.gr.2014.07.006
Liu, S. W., Wang, W., Bai, X., et al., 2018. Lithological Assemblages of Archean Meta-Igneous Rocks in Eastern Hebei-Western Liaoning Provinces of North China Craton, and Their Geodynamic Implications. Earth Science-Journal of China University of Geosciences, 43: 44-56. DOI:10.3799/dqkx.2018.003
Liu, S. W., Lü, Y. J., Feng, Y. G., et al., 2007. Geology and Zircon U-Pb Isotopic Chronology of Dantazi Complex, Northern Hebei Province. Earth Science-Journal of China University of Geosciences, 13: 484-497.
Liu, S. W., Pan, Y. M., Xie, Q. L., et al., 2004. Archean Geodynamics in the Central Zone, North China Craton:Constraints from Geochemistry of Two Contrasting Series of Granitoids in the Fuping and Wutai Complexes. Precambrian Research, 130(1/2/3/4): 229-249. DOI:10.1016/j.precamres.2003.12.001
Liu, S. W., Pan, Y. M., Li, J. H., et al., 2002. Geological and Isotopic Geochemical Constraints on the Evolution of the Fuping Complex, North China Craton. Precambrian Research, 117(1/2): 41-56. DOI:10.1016/s0301-9268(02)00063-3
Liu, Y. S., Hu, Z. C., Gao, S., et al., 2008. In situ Analysis of Major and Trace Elements of Anhydrous Minerals by LA-ICP-MS without Applying an Internal Standard. Chemical Geology, 257(1/2): 34-43. DOI:10.1016/j.chemgeo.2008.08.004
Liu, Y. S., Hu, Z. C., Zong, K. Q., et al., 2010. Reappraisement and Refinement of Zircon U-Pb Isotope and Trace Element Analyses by LA-ICP-MS. Chinese Science Bulletin, 55(15): 1535-1546. DOI:10.1007/s11434-010-3052-4
Lu, J. S., Zhai, M. G., Lu, L. S., et al., 2017. P-T-t Evolution of Neoarchaean to Paleoproterozoic Pelitic Granulites from the Jidong Terrane, Eastern North China Craton. Precambrian Research, 290: 1-15. DOI:10.1016/j.precamres.2016.12.012
Lu, Y. J., Loucks, R. R., Fiorentini, M. L., et al., 2015. Fluid Flux Melting Generated Postcollisional High Sr/Y Copper Ore-Forming Water-Rich Magmas in Tibet. Geology, 43(7): 583-586. DOI:10.1130/g36734.1
Ludwig, K. R., 2003. User's Manual for Isoplot 3.00: A Geochronological Toolkit for Microft Excel. Berkeley Geochronology Center Special Publication, Berkeley. 4: 25-39
Lü, B., Zhai, M. G., Li, T. S., et al., 2012. Zircon U-Pb Ages and Geochemistry of the Qinglong Volcano-Sedimentary Rock Series in Eastern Hebei:Implication for~2 500 Ma Intra-Continental Rifting in the North China Craton. Precambrian Research, 208-211: 145-160. DOI:10.1016/j.precamres.2012.04.002
Martin, H., Moyen, J. F., Rapp, R., 2009. The Sanukitoid Series:Magmatism at the Archaean-Proterozoic Transition. Earth and Environmental Science Transactions of the Royal Society of Edinburgh, 100(1/2): 15-33. DOI:10.1017/s1755691009016120
Martin, H., Smithies, R. H., Rapp, R., et al., 2005. An Overview of Adakite, Tonalite-Trondhjemite-Granodiorite (TTG), and Sanukitoid:Relationships and Some Implications for Crustal Evolution. Lithos, 79(1/2): 1-24. DOI:10.1016/j.lithos.2004.04.048
Martin, H., 1999. Adakitic Magmas:Modern Analogues of Archaean Granitoids. Lithos, 46(3): 411-429. DOI:10.1016/s0024-4937(98)00076-0
Martin, H., 1994. The Archean Grey Gneisses and the Genesis of the Continental Crust. In: Condie, K. C., ed., The Archean Crustal Evolution, Developments in Precambrian Geology. Elsevier, Amsterdam. 205-259
Martin, L. A. J., Duchêne, S., Deloule, E., et al., 2008. Mobility of Trace Elements and Oxygen in Zircon during Metamorphism:Consequences for Geochemical Tracing. Earth and Planetary Science Letters, 267(1/2): 161-174. DOI:10.1016/j.epsl.2007.11.029
Mason, G. H., 1985. The Mineralogy and Textures of the Coastal Batholith, Peru. In: Pitcher, W. S., Atherton, A. M., Cobbing E. J., et al., eds., Magmatism at a Plate Edge: the Peruvian Andes. Blackie, Glasgow. 156-166 http://www.mendeley.com/catalog/coastal-batholith-central-peru/
McCulloch, M. T., Gamble, J. A., 1991. Geochemical and Geodynamical Constraints on Subduction Zone Magmatism. Earth and Planetary Science Letters, 102(3/4): 358-374. DOI:10.1016/0012-821x(91)90029-h
McDonough, W. F., 2003. Compositional Model for the Earth's Core. In: Carlson, R. W., ed., The Mantle and Core, Treatise on Geochemistry. Elsevier, Amsterdam. 2: 547-568 http://www.mendeley.com/catalog/compositional-model-earths-core/
McDonough, W. F., Sun, S. S., 1995. The Composition of the Earth. Chemical Geology, 120(3/4): 223-253. DOI:10.1016/0009-2541(94)00140-4
Mehnert, K. R., 1968. Migmatites and the Origin of Granitic Rocks. Elsevier, Amsterdam http://adsabs.harvard.edu/abs/1969ChGeo...4..471M
Middlemost, E. A. K., 1994. Naming Materials in the Magma/Igneous Rock System. Earth-Science Reviews, 37(3/4): 215-224. DOI:10.1016/0012-8252(94)90029-9
Miyashiro, A., 1994. Metamorphic Petrology. UCL Press, London.
Miyashiro, A., 1973. Metamorphic Facies and Facies Series:Metamorphism and Metamorphic Belts. Springer, Netherlands.
Molina, J. F., Moreno, J. A., Castro, A., et al., 2015. Calcic Amphibole Thermobarometry in Metamorphic and Igneous Rocks:New Calibrations Based on Plagioclase/Amphibole Al-Si Partitioning and Amphibole/Liquid Mg Partitioning. Lithos, 232: 286-305. DOI:10.1016/j.lithos.2015.06.027
Moyen, J. F., Martin, H., 2012. Forty Years of TTG Research. Lithos, 148: 312-336. DOI:10.1016/j.lithos.2012.06.010
Mullen, E. D., 1983. MnO/TiO2/P2O5:A Minor Element Discriminant for Basaltic Rocks of Oceanic Environments and Its Implications for Petrogenesis. Earth and Planetary Science Letters, 62(1): 53-62. DOI:10.1016/0012-821x(83)90070-5
Nehring, F., Foley, S. F., Hölttä, P., et al., 2009. Internal Differentiation of the Archean Continental Crust:Fluid-Controlled Partial Melting of Granulites and TTG-Amphibolite Associations in Central Finland. Journal of Petrology, 50(1): 3-35. DOI:10.1093/petrology/egn070
Nutman, A. P., Wan, Y. S., Du, L. L., et al., 2011. Multistage Late Neoarchean Crustal Evolution of the North China Craton, Eastern Hebei. Precambrian Research, 189(1/2): 43-65. DOI:10.1016/j.precamres.2011.04.005
Palme, H., O'Nell, H. S. C., 2003. Cosmochemical Estimates of Mantle Composition. In: Carlson, R. W., ed., The Mantle and Core, Treatise on Geochemistry. Elsevier, Amesterdam. 2: 1-28
Pearce, J. A., 2008. Geochemical Fingerprinting of Oceanic Basalts with Applications to Ophiolite Classification and the Search for Archean Oceanic Crust. Lithos, 100(1/2/3/4): 14-48. DOI:10.1016/j.lithos.2007.06.016
Pearce, J. A., 1996. An User's Guide to Basalt Discrimination Diagrams. In: Wyman, D. A., ed., Trace Element Geochemistry of Volcanic Rocks: Applications for Massive Sulphide Exploration. Geological Association of Canada, Short Course Notes. 12: 79-113
Pearce, J. A., Peate, D. W., 1995. Tectonic Implications of the Composition of Volcanic Arc Magmas. Annual Review of Earth and Planetary Sciences, 23(1): 251-285. DOI:10.1146/annurev.ea.23.050195.001343
Pearce, J. A., Cann, J. R., 1973. Tectonic Setting of Basic Volcanic Rocks Determined Using Trace Element Analyses. Earth and Planetary Science Letters, 19(2): 290-300. DOI:10.1016/0012-821x(73)90129-5
Peng, P., Wang, C., Wang, X. P., et al., 2015. Qingyuan High-Grade Granite-Greenstone Terrain in the Eastern North China Craton:Root of a Neoarchaean Arc. Tectonophysics, 662: 7-21. DOI:10.1016/j.tecto.2015.04.013
Polat, A., Li, J., Fryer, B., et al., 2006. Geochemical Characteristics of the Neoarchean (2 800-2 700 Ma) Taishan Greenstone Belt, North China Craton:Evidence for Plume-Craton Interaction. Chemical Geology, 230(1/2): 60-87. DOI:10.1016/j.chemgeo.2005.11.012
Plyusnina, L. P., 1982. Geothermometry and Geobarometry of Plagioclase-Hornblende Bearing Assemblages. Contributions to Mineralogy and Petrology, 80(2): 140-146. DOI:10.1007/bf00374891
Rapp, R. P., Shimizu, N., Norman, M. D., 2003. Growth of Early Continental Crust by Partial Melting of Eclogite. Nature, 425(6958): 605-609. DOI:10.1038/nature02031
Rapp, R. P., Shimizu, N., Norman, M. D., et al., 1999. Reaction between Slab-Derived Melts and Peridotite in the Mantle Wedge:Experimental Constraints at 3.8 GPa. Chemical Geology, 160(4): 335-356. DOI:10.1016/s0009-2541(99)00106-0
Ross, P. S., Bédard, J. H., 2009. Magmatic Affinity of Modern and Ancient Subalkaline Volcanic Rocks Determined from Trace-Element Discriminant Diagrams. Canadian Journal of Earth Sciences, 46(11): 823-839. DOI:10.1139/e09-054
Rubatto, D., 2002. Zircon Trace Element Geochemistry:Partitioning with Garnet and the Link between U-Pb Ages and Metamorphism. Chemical Geology, 184(1/2): 123-138. DOI:10.1016/s0009-2541(01)00355-2
Sajona, F. G., Maury, R. C., Bellon, H., et al., 1996. High Field Strength Element Enrichment of Pliocene-Pleistocene Island Arc Basalts, Zamboanga Peninsula, Western Mindanao (Philippines). Journal of Petrology, 37(3): 693-726. DOI:10.1093/petrology/37.3.693
Sang, L. K., Ma, C. Q., 2012. Petrology. Second Edition. Geological Publishing House, Beijing. 441-449.
Saunders, A. D., Norry, M. J., Tarney, J., 1991. Fluid Influence on the Trace Element Compositions of Subduction Zone Magmas. Philosophical Transactions of the Royal Society of London Series A:Physical and Engineering Sciences, 335(1638): 377-392. DOI:10.1098/rsta.1991.0053
Sawyer, E. W., 2008a. Atlas of Migmatites. The Canadian Mineralogist, Special Publication 9. NRC Research Press, Ottawa, Ontario. 371
Sawyer, E. W., 2008b. Nomenclature for the Constituent Parts. In: Sawyer, E. W., Brown, M., eds., Working with Migmatites. Mineralogical Association of Canada, Short Course 38. 1-24
Sawyer, E. W., 1999. Criteria for the Recognition of Partial Melting. Physics and Chemistry of the Earth, Part A:Solid Earth and Geodesy, 24(3): 269-279. DOI:10.1016/s1464-1895(99)00029-0
Sawyer, E. W., 1998. Formation and Evolution of Granite Magmas during Crustal Reworking:The Significance of Diatexites. Journal of Petrology, 39(6): 1147-1167. DOI:10.1093/petroj/39.6.1147
Sederholm, J. J., 1907. On Granite and Gneiss:Their Origin, Relations and Occurrence in the Precambrian Complex of Fennoxcandia. Bull Comment Geology Finlande, 23.
Shan, H. X., Zhai, M. G., Oliveira, E. P., et al., 2015. Convergent Margin Magmatism and Crustal Evolution during Archean-Proterozoic Transition in the Jiaobei Terrane:Zircon U-Pb Ages, Geochemistry, and Nd Isotopes of Amphibolites and Associated Grey Gneisses in the Jiaodong Complex, North China Craton. Precambrian Research, 264: 98-118. DOI:10.1016/j.precamres.2015.04.008
Siivola, J., Schmid, R., 2007. List of Mineral Abbreviations. In: Fettes, D., Desmons, J., eds., Metamorphic Rocks: A Classification and Glossary of Terms. Cambridge University Press, Cambridge. 93-110
Smithies, R. H., 2000. The Archaean Tonalite-Trondhjemite-Granodiorite (TTG) Series is not an Analogue of Cenozoic Adakite. Earth and Planetary Science Letters, 182(1): 115-125. DOI:10.1016/s0012-821x(00)00236-3
Spandler, C., Pirard, C., 2013. Element Recycling from Subducting Slabs to Arc Crust:A Review. Lithos, 170/171: 208-223. DOI:10.1016/j.lithos.2013.02.016
Stern, C. R., Kilian, R., 1996. Role of the Subducted Slab, Mantle Wedge and Continental Crust in the Generation of Adakites from the Andean Austral Volcanic Zone. Contributions to Mineralogy and Petrology, 123(3): 263-281. DOI:10.1007/s004100050155
Sun, S. S., McDonough, W. F., 1989. Chemical and Isotopic Systematics of Oceanic Basalts:Implications for Mantle Composition and Processes. Geological Society, London, Special Publications, 42(1): 313-345. DOI:10.1144/gsl.sp.1989.042.01.19
Tang, L., Santosh, M., Tsunogae, T., et al., 2016. Late Neoarchean Arc Magmatism and Crustal Growth Associated with Microblock Amalgamation in the North China Craton:Evidence from the Fuping Complex. Lithos, 248-251: 324-338. DOI:10.1016/j.lithos.2016.01.022
Tarney, J., 1976. Geochemistry of Archaean High-Grade Gneisses, with Implications as to the Origin and Evolution of the Precambrian Crust. In: Windley, B. F., ed., The Early History of Earth. Wiley, London. 405-417
Taylor, S. R., McLennan, S. M., 1985. The Continental Crust: Its Composition and Evolution. Blackwell Scientific Publications, Oxford. 312
Vavra, G., Schmid, R., Gebauer, D., 1999. Internal Morphology, Habit and U-Th-Pb Microanalysis of Amphibolite-to-Granulite Facies Zircons:Geochronology of the Ivrea Zone (Southern Alps). Contributions to Mineralogy and Petrology, 134(4): 380-404. DOI:10.1007/s004100050492
Vernon, R. H, Clarke, G. L., 2008. Principles of Metamorphic Petrology. Cambridge University Press, New York. 446
Walker, K. R., Joplin, G. A., Lovering, J. F., et al., 1959. Metamorphic and Metasomatic Convergence of Basic Igneous Rocks and Lime-Magnesia Sediments of the Precambrian of North-Western Queensland. Journal of the Geological Society of Australia, 6(2): 149-177. DOI:10.1080/00167615908728504
Wan, Y. S., Dong, C. Y., Xie, H. Q., et al., 2018. Formation Age of BIF-Bearing Anshan Group Supracrustal Rocks in Anshan-Benxi Area:New Evidence from SHRIMP U-Pb Zircon Dating. Earth Science-Journal of China University of Geosciences, 43: 57-81. DOI:10.3799/dqkx.2018.004
Wan, Y. S., Wang, S. J., Reng, P., et al., 2015. Neoarchean Magmatism in the Culaishan Area, Western Shandong:Evidence from SHRIMP Zircon U-Pb Dating. Acta Geoscientica Sinica, 36: 634-646.
Wan, Y. S., Xie, S. W., Yang, C. H., et al., 2014a. Early Neoarchean (~2.7 Ga) Tectono-Thermal Events in the North China Craton:A Synthesis. Precambrian Research, 247: 45-63. DOI:10.1016/j.precamres.2014.03.019
Wan, Y. S., Dong, C. Y., Wang, S. J., et al., 2014b. Middle Neoarchean Magmatism in Western Shandong, North China Craton:SHRIMP Zircon Dating and LA-ICP-MS Hf Isotope Analysis. Precambrian Research, 255: 865-884. DOI:10.1016/j.precamres.2014.07.016
Wan, Y. S., Dong, C. Y., Liu, D. Y., et al., 2012. Zircon Ages and Geochemistry of Late Neoarchean Syenogranites in the North China Craton:A Review. Precambrian Research, 222/223: 265-289. DOI:10.1016/j.precamres.2011.05.001
Wan, Y. S., Liu, D. Y., Wang, S. J., et al., 2010. Juvenile Magmatism and Crustal Recycling at the End of the Neoarchean in Western Shandong Province, North China Craton:Evidence from SHRIMP Zircon Dating. American Journal of Science, 310(10): 1503-1552. DOI:10.2475/10.2010.11
Wang, F., Xiao, L., Xiao, W. S., 1990. The Petrological and Geochemical Evidences for the Archean Origin of Guandi Complex near Zhoukoudian, Beijing. Earth Science-Journal of China University of Geosciences, 15: 530-538.
Wang, F. Z., Chen, N.-S., 1996. Field Trip Guide T208-Regional and Thermodynamic Metamorphism of the Western Hills, Beijing. Geological Publishing House, Beijing.
Wang, J. P., Kusky, T. M., Wang, L., et al., 2015. A Neoarchean Subduction Polarity Reversal Event in the North China Craton. Lithos, 220-223: 133-146. DOI:10.1016/j.lithos.2015.01.029
Wang, Q., Wyman, D. A., Xu, J. F., et al., 2007. Partial Melting of Thickened or Delaminated Lower Crust in the Middle of Eastern China:Implications for Cu-Au Mineralization. The Journal of Geology, 115(2): 149-161. DOI:10.1086/510643
Wang, R. M., Wan, Y. S., Cheng, S. H., et al., 2009. Modern-Style Subduction Processes in the Archean:Evidence from the Shangyi Complex in North China Craton. Acta Geologica Sinica-English Edition, 83(3): 535-543. DOI:10.1111/j.1755-6724.2009.00055.x
Wang, R. M., He, G. P., Chen, Z. Z., et al., 1987. Discrimination Diagrams for Protoliths of Metamorphic Rocks. Geological Publishing House, Beijing.
Wang, W., Liu, S. W., Cawood, P. A., et al., 2016. Late Neoarchean Subduction-Related Crustal Growth in the Northern Liaoning Region of the North China Craton:Evidence from~2.55 to 2.50 Ga Granitoid Gneisses. Precambrian Research, 281: 200-223. DOI:10.1016/j.precamres.2016.05.018
Wang, W., Liu, S. W., Santosh, M., et al., 2015. Neoarchean Intra-Oceanic Arc System in the Western Liaoning Province:Implications for Early Precambrian Crustal Evolution in the Eastern Block of the North China Craton. Earth-Science Reviews, 150: 329-364. DOI:10.1016/j.earscirev.2015.08.002
Wang, W., Zhai, M. G., Li, T. S., et al., 2014. Archean-Paleoproterozoic Crustal Evolution in the Eastern North China Craton:Zircon U-Th-Pb and Lu-Hf Evidence from the Jiaobei Terrane. Precambrian Research, 241: 146-160. DOI:10.1016/j.precamres.2013.11.011
Wang, W., Liu, S. W., Santosh, M., et al., 2013. Zircon U-Pb-Hf Isotopes and Whole-Rock Geochemistry of Granitoid Gneisses in the Jianping Gneissic Terrane, Western Liaoning Province:Constraints on the Neoarchean Crustal Evolution of the North China Craton. Precambrian Research, 224: 184-221. DOI:10.1016/j.precamres.2012.09.019
Wang, W., Liu, S. W., Wilde, S. A., et al., 2012. Petrogenesis and Geochronology of Precambrian Granitoid Gneisses in Western Liaoning Province:Constraints on Neoarchean to Early Paleoproterozoic Crustal Evolution of the North China Craton. Precambrian Research, 222/223: 290-311. DOI:10.1016/j.precamres.2011.10.023
Wang, Y., Zhou, L. Y., Li, J. Y., 2011. Intracontinental Superimposed Tectonics-A Case Study in the Western Hills of Beijing, Eastern China. Geological Society of America Bulletin, 123(5/6): 1033-1055. DOI:10.1130/b30257.1
Wei, C. J., Guan, X., Dong, J., 2017. HT-UHT Metamorphism of Metabasites and the Petrogenesis of TTGs. Acta Petrologica Sinica, 33: 1381-1404.
Whitehouse, M. J., Kamber, B. S., 2003. A Rare Earth Element Study of Complex Zircons from Early Archaean Amítsoq Gneisses, Godthåbsfjord, South-West Greenland. Precambrian Research, 126(3/4): 363-377. DOI:10.1016/s0301-9268(03)00105-0
Whitehouse, M. J., Platt, J. P., 2003. Dating High-Grade Metamorphism-Constraints from Rare-Earth Elements in Zircon and Garnet. Contributions to Mineralogy and Petrology, 145(1): 61-74. DOI:10.1007/s00410-002-0432-z
Winter, J. D., 2010. An Introduction of Igneous and Metamorphic Petrology (Second Edition). Prentice Hall, New York.
Wu, M. L., 2015. Ages, Geochemistry and Metamorphism of Neoarchean Basement in Shandong Province:Implications for the Evolution of the North China Craton. Springer: 146-165.
Wu, M. L., Zhao, G. C., Sun, M., et al., 2013. Zircon U-Pb Geochronology and Hf Isotopes of Major Lithologies from the Yishui Terrane:Implications for the Crustal Evolution of the Eastern Block, North China Craton. Lithos, 170/171: 164-178. DOI:10.1016/j.lithos.2013.03.005
Wu, Y. B., Zheng, Y. F., 2004. Genesis of Zircon and Its Constraints on Interpretation of U-Pb Age. Chinese Science Bulletin, 49(15): 1554-1569. DOI:10.1007/bf03184122
Xia, B., Zhang, L. F., Bader, T., 2014. Zircon U-Pb Ages and Hf Isotopic Analyses of Migmatite from the 'Paired Metamorphic Belt' in Chinese SW Tianshan:Constraints on Partial Melting Associated with Orogeny. Lithos, 192-195: 159-179. DOI:10.1016/j.lithos.2014.02.003
Xie, Q. L., Kerrich, R., 1994. Silicate-Perovskite and Majorite Signature Komatiites from the Archean Abitibi Greenstone Belt:Implications for Early Mantle Differentiation and Stratification. Journal of Geophysical Research, 99(B8): 15799-15812. DOI:10.1029/94jb00544
Xiong, X. L., Keppler, H., Audétat, A., et al., 2009. Experimental Constraints on Rutile Saturation during Partial Melting of Metabasalt at the Amphibolite to Eclogite Transition, with Applications to TTG Genesis. American Mineralogist, 94(8/9): 1175-1186. DOI:10.2138/am.2009.3158
Xu, J. F., Shinjo, R., Defant, M. J., et al., 2002. Origin of Mesozoic Adakitic Intrusive Rocks in the Ningzhen Area of East China:Partial Melting of Delaminated Lower Continental Crust?. Geology, 30(12): 1111-1114. DOI:10.1130/0091-7613(2002)030<1111:oomair>2.0.co;2
Yakymchuk, C. J. A., 2014. Anatexis and Crustal Differentiation: Insights from the Fosdick Migmatite-Granite Complex, West Antarctica: [Dissertations]. University of Maryland, Maryland. 1-6 http://hdl.handle.net/1903/15755
Yan, D. P., Zhou, M. F., Song, H. L., 2005. A Geochronological Constraint to the Guandi Complex, Western Hills of Beijing, and Its Implications for the Tectonic Evolution. Earth Science Frontiers, 12: 332-337.
Yang, J. H., Wu, F. Y., Wilde, S. A., et al., 2008. Petrogenesis and Geodynamics of Late Archean Magmatism in Eastern Hebei, Eastern North China Craton:Geochronological, Geochemical and Nd-Hf Isotopic Evidence. Precambrian Research, 167(1/2): 125-149. DOI:10.1016/j.precamres.2008.07.004
Yang, Q. Y., Santosh, M., Collins, A. S., et al., 2016. Microblock Amalgamation in the North China Craton:Evidence from Neoarchaean Magmatic Suite in the Western Margin of the Jiaoliao Block. Gondwana Research, 31: 96-123. DOI:10.1016/j.gr.2015.04.002
Yip, N., 2016. A Comparative Study on Zircon Hf Isotopes of Neoarchean Tonalite-Trondhjemite-Granodiorite (TTG) in Trans-North China Orogen and Eastern Block of the North China Craton: [Dissertations]. University of Hong Kong, Hong Kong
Yuan, D. Y., Li, D. W., Chen, Q., et al., 2016. Geochronology and Geochemical Characteristics of Amphibolite in Guandi Complex, Zhoukoudian Area and Its Geological Significance. Northwestern Geology, 49: 149-164.
Zegers, T. E., van Keken, P. E., 2001. Middle Archean Continent Formation by Crustal Delamination. Geology, 29(12): 1083-1086. DOI:10.1130/0091-7613(2001)029<1083:macfbc>2.0.co;2
Zhai, M. G., 2014. Multi-Stage Crustal Growth and Cratonization of the North China Craton. Geoscience Frontiers, 5(4): 457-469. DOI:10.1016/j.gsf.2014.01.003
Zhai, M. G., Santosh, M., 2013. Metallogeny of the North China Craton:Link with Secular Changes in the Evolving Earth. Gondwana Research, 24(1): 275-297. DOI:10.1016/j.gr.2013.02.007
Zhai, M. G., Santosh, M., 2011. The Early Precambrian Odyssey of the North China Craton:A Synoptic Overview. Gondwana Research, 20(1): 6-25. DOI:10.1016/j.gr.2011.02.005
Zhai, M. G., Guo, J. H., Liu, W. J., 2005. Neoarchean to Paleoproterozoic Continental Evolution and Tectonic History of the North China Craton:A Review. Journal of Asian Earth Sciences, 24(5): 547-561. DOI:10.1016/j.jseaes.2004.01.018
Zhai, M. G., Yang, R. Y., Lu, W. J., et al., 1985. Geochemistry and Evolution of the Qingyuan Archaean Granite-Greenstone Terrain, NE China. Precambrian Research, 27(1/2/3): 37-62. DOI:10.1016/0301-9268(85)90005-1
Zhao, G. C., Zhai, M. G., 2013. Lithotectonic Elements of Precambrian Basement in the North China Craton:Review and Tectonic Implications. Gondwana Research, 23(4): 1207-1240. DOI:10.1016/j.gr.2012.08.016
Zhao, G. C., Sun, M., Wilde, S. A., et al., 2005. Late Archean to Paleoproterozoic Evolution of the North China Craton:Key Issues Revisited. Precambrian Research, 136(2): 177-202. DOI:10.1016/j.precamres.2004.10.002
Zhao, G. C., Wilde, S. A., Cawood, P. A., et al., 2001. Archean Blocks and Their Boundaries in the North China Craton:Lithological, Geochemical, Structural and P-T Path Constraints and Tectonic Evolution. Precambrian Research, 107(1/2): 45-73. DOI:10.1016/S0301-9268(00)00154-6
Zhao, G. C., Wilde, S. A., Cawood, P. A., et al., 1998. Thermal Evolution of Archean Basement Rocks from the Eastern Part of the North China Craton and Its Bearing on Tectonic Setting. International Geology Review, 40(8): 706-721. DOI:10.1080/00206819809465233
Zhao, W. X., 2003. Geology and Field Work in Zhoukoudian and High-Tech Application. China University of Geosciences Press, Wuhan. 10
Zhang, R. S., Si, R., Song, B., 1998. Komatiite in Sujiagou Village of Mengyin Country. Shandong Geology, 14: 26-33.
Zhou, Y. Y., Zhao, T. P., Sun, Q. Y., et al., 2018. Geochronological and Geochemical Constraints on the Petrogenesis of the 2.6-2.5 Ga Amphibolites, Low-and High-Al TTGs in the Wangwushan Area, Southern North China Craton:Implications for the Neoarchean Crustal Evolution. Precambrian Research, 307: 93-114. DOI:10.1016/j.precamres.2018.01.013