Mafic and Felsic Intrusions in the Ailao Shan–Red River Belt: Geochemical Constraints on the Paleogeographic Position of the South China Block

RESEARCH

Petrogenesis of mid-Neoproterozoic (ca. 750 Ma) mafic and felsic intrusions in the Ailao Shan–Red River belt: Geochemical constraints on the paleogeographic position of the South China block

Zheng Liu1, Shu-Cheng Tan1,*, Xiao-Hu He1, Dong-Bing Wang2, and Bo Gao1 1SCHOOL OF RESOURCE ENVIRONMENT AND EARTH SCIENCE, YUNNAN UNIVERSITY, KUNMING 650091, CHINA 2CHENGDU CENTER, CHINESE GEOLOGICAL SURVEY, CHENGDU 610081, CHINA

ABSTRACT

Abundant mid-Neoproterozoic magmatic rocks are exposed in the western Yangtze block, a part of the South China block. Currently, based on contrasting interpretations of their origin, two competing reconstruction models, the internal model and the external model, have been formulated to constrain the paleogeographic position of the South China block in Rodinia. In this study, we examined 17 representative samples from three intrusions (Kuchahe, Leidashu, and Qizanmi) within the Ailao Shan–Red River belt, located in the southwestern Yangtze block. Laser-ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) zircon U-Pb dating suggests that they were emplaced during the mid-Neoproterozoic (ca. 750 Ma). The Kuchahe and Leidashu intrusions share geochemical characteristics of S-type

and A2-type rocks, respectively. Elemental and isotopic data suggest that the Kuchahe intrusion was derived by biotite-dehydration melting of a metapelitic source, whereas the Leidashu intrusion was produced by partial melting of earlier Neoproterozoic granodiorites in the middle crust (~15 km), with mixing of basaltic magmas. The Qizanmi intrusion is composed of hornblende gabbro and was likely derived by partial melting of a shallow and enriched lithospheric mantle source modified by slab-released fluids, with accumulation of plagioclase and fractionation of mafic minerals. The three intrusions were emplaced in a back-arc setting, in response to the roll-back of a subducted slab rather than mantle plume activity. The mid-Neoproterozoic (ca. 750 Ma) subduction process argues against the South China block occupying an internal setting in Rodinia, which was finally assembled before 0.9 Ga.

LITHOSPHERE; v. 11; no. 3; p. 348–364; GSA Data Repository Item 2019129 | Published online 18 March 2019 https://doi.org/10.1130/L1038.1

INTRODUCTION 2009) versus an external location along the supercontinental margin (e.g., Zhou et al., 2002; J.H. Zhao et al., 2008a; X.L. Wang et al., 2006, 2008, In the Proterozoic, the supercontinent Rodinia was assembled during 2013c, 2014; Wang and Zhou, 2012; Zhang et al., 2012; Cawood et al., the global Grenvillian orogenesis (e.g., Z.X. Li et al., 2008; Cawood et 2013, 2017; F. Wang et al., 2013a; Zhao, 2015; J.Y. Li et al., 2018). In the al., 2017). However, the paleogeographic position of the South China internal model, the amalgamation between the two blocks is considered block in Rodinia is still debated. The South China block consists of to have occurred from ca. 1.0 Ga to 0.90 Ga (e.g., Z.X. Li et al., 2002b, the Yangtze block and Cathaysia block. The collision between the two 2007; X.H. Li et al., 2009; see Figs. 1A and 1B herein). Subsequent blocks gave rise to the Jiangnan orogen (e.g., Z.X. Li et al., 2002b, 2008; drifting of the South China block from Rodinia triggered by a mantle Zhao, 2015; Cawood et al., 2017). Abundant Neoproterozoic magmatic plume is proposed to have produced intensive magmatism between ca. rocks occur across the Yangtze block as the result of ancient oceanic 850 and 745 Ma and rift-related sedimentary sequences (e.g., X.H. Li subduction, mantle plume activity, continent-continent collision, and/or et al., 2002a, 2003a, 2005; Z.X. Li et al., 2002b, 2003b, 2008). On the intracontinental rifting (e.g., Z.X. Li et al., 1995, 2002b, 2003b, 2008; contrary, final assembly between the two blocks indicated by the external X.H. Li et al., 2002a, 2003a, 2005, 2009; X.L. Wang et al., 2006, 2008, model (Fig. 1C) did not occur until ca. 830–810 Ma, and arc magmatism 2013c, 2014; Dong et al., 2012; Wang and Zhou, 2012; W. Wang et al., along the western Yangtze block continued to ca. 730 Ma (e.g., Zhou 2013b; Cai et al., 2015; G. Zhao, 2015; Cawood et al., 2017; J.Y. Li et et al., 2002, 2006a, 2006b; Zhao, 2015). Thus, further investigation to al., 2018; J.H. Zhao et al., 2008a). Based on competing explanations determine the precise origin of the Neoproterozoic magmatic rocks of for these rocks in the South China block, two contrasting models have the western Yangtze block is important for constraining the location of been proposed (Fig. 1): an internal setting within Rodinia (e.g., Z.X. the South China block within Rodinia. Li et al., 1995, 2002b, 2003b, 2008; X.H. Li et al., 2002a, 2003a, 2005, In this paper, we investigated Neoproterozoic granitoids (Leidashu and Kuchahe) and mafic rocks (Qizanmi) from the Ailao Shan–Red River belt, *Corresponding author: [email protected] located at the southwestern Yangtze block. New laser ablation–inductively

setting where they were emplaced, and (3) the paleogeographic location of the South China block in Rodinia. All the new data, combined with published data, suggest that the western Yangtze block was located along a convergent continental margin during the mid-Neoproterozoic, rather than representing a continental rift triggered by a mantle plume.

GEOLOGICAL CONTEXT AND SAMPLING

The South China block consists of the Yangtze block and Cathaysia block. The collision between the two blocks occurred at ca. 1000 Ma (e.g., Z.X. Li et al., 2002b) or between 830 and 800 Ma (e.g., X.L. Wang et al., 2008, 2013c; Zhao, 2015), producing the Jiangnan orogen. Sensitive high-resolution ion microprobe (SHRIMP) zircon U-Pb ages (ca. 968 Ma) of the Xiwan plagiogranites within the NE Jiangxi ophiolites suggest that the Jiang orogen was a part of the Grenvillian orogenic belt (Li et al., 1994). However, new data from magmatic rocks and sedimentary strata imply that the final collision between the two blocks occurred at ca. 830–800 Ma (e.g., Wang et al., 2008; W. Wang et al., 2013b), i.e., sub- stantially younger than the Grenvillian period. LA-ICP-MS U-Pb ages of detrital and magmatic zircons from the volcanic-sedimentary strata in the Jiangnan orogen demonstrate that its folded basement sequences were produced during the period 860–825 Ma (Wang et al., 2014). Wang et al. (2014) considered that the final amalgamation between the two blocks occurred subsequent to ca. 825 Ma. The Yangtze block features a poorly exposed Archean to Paleopro- terozoic basement that is unconformably overlain by variably deformed and metamorphosed Neoproterozoic to Mesozoic volcanic-sedimentary successions (Zhao and Cawood, 2012). The oldest rocks in the Yangtze block are the ca. 3.45 Ga protoliths of the Kongling tonalite-trondhjemite- granodiorite (TTG) gneisses (Guo et al., 2014). The Ailao Shan–Red River belt is located between the South China block and the Indochina block (Fig. 2). It has similar mid-Neoproterozoic magmatism, sedimentary records, and basement as the Yangtze block (Chen et al., 2017). Thus, Chen et al. (2017) argued that the belt should belong to the South China block rather than the Indochina block. The Ailao Shan–Red River belt includes four metamorphic massifs, designated as: Xuelong Shan, Dian- cang Shan, Ailao Shan, and Phan Si Pan. The basements in the four massifs are Archean to Paleoproterozoic high-grade metamorphic rocks (F. Wang et al., 2013a; W. Wang, 2016a). Paleozoic to Mesozoic rocks lie to the west of the basement rocks. These rocks were generally mylonitized by Cenozoic Ailao Shan–Red River shearing activity (Tapponnier et al., 1990). The Ailao Shan massif has high-grade metamorphic basement (amphibolite facies) with a Mesoproterozoic protolith age. It consists of marbles, calc-silicates, schists, gneisses, amphibolites, and granulites. Paleozoic–Mesozoic low-grade metamorphic strata occur along the Ailao Shan–Red River belt to the southwest (Fig. 3A). They are composed of Figure 1. Rodinia reconstruction (A) at 1.0 Ga and (B) at 0.9 Ga in the phyllites, mica schists, and garnet–mica schists. internal model (Z.X. Li et al., 2008), and (C) at 0.9 Ga in the external model In this contribution, we investigated the Kuchahe, Leidashu, and Qiza- (Cawood et al., 2017). Y—Yangtze block; CA—Cathaysia block; Ant—Ant- nmi intrusions, which were emplaced into the high-grade metamorphic arctica; Mad—Madagascar. rocks (Fig. 3B). All three intrusions exhibit significant mylonitization. The Kuchahe intrusion consists of gray-white, medium- to fine-grained two- mica granite (Fig. 4) with a composition of quartz (25%–35%), K-feldspar coupled plasma–mass spectrometry (LA-ICP-MS) zircon U-Pb dating, (30%–40%), plagioclase (10%–20%), muscovite (5%–10%), and biotite whole-rock geochemical and isotopic data, and in situ zircon Hf iso- (~3%), as well accessory minerals such as zircon and apatite. The Lei- topic data were obtained to investigate the petrogenesis and associated dashu intrusion is composed mainly of gray quartz monzonite porphyry geodynamic mechanisms of these rocks. Our approach was based on the (Fig. 4). The phenocrysts (15%–20%) are composed of K-feldspar and pla- understanding that different magmatic assemblages occur in response gioclase, whereas the groundmass (80%–85%) consists of quartz (10%– to continental breakup and oceanic subduction in the Wilson cycle. The 15%), plagioclase (30%–55%), K-feldspar (10%–40%), biotite (3%–15%), main objectives of this work were therefore to constrain: (1) the petro- and amphibole (~5%). Zircon, sphene, and apatite are common acces- genesis of the studied Neoproterozoic magmatic rocks, (2) the tectonic sory minerals. The Qizanmi intrusion contains medium- to fine-grained

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by guest Downloaded from http://pubs.geoscienceworld.org/gsa/lithosphere/article-pdf/11/3/348/4698799/348.pdf ZHENG LIU ET AL. | Mid-Neoproterozoic intrusions from the western Yangtze block RESEARCH Figure 3. (A) Simplified geological map of the Ailaoshan zone (Cai et al., 2015). (B) Geological map of the studied area and sampling locations. area (B) Geological map of the studied 2015). zone (Cai et al., Ailaoshan geological map of the (A) Simplified 3. Figure A

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hornblende gabbro (Fig. 4) and consists of hornblende (40%–50%) and plagioclase (50%–60%), with minor amounts of sphene and apatite as common accessory minerals. It is worth noting that some plagioclase is locally altered to sericite and zoisite. Seventeen representative samples from the three intrusions were sampled for analysis, and we present detailed sampling locations in Figure 3B.

ANALYTICAL METHODS AND RESULTS

All samples were subjected to bulk geochemical and Sr-Nd isotopic analyses. Four samples (10AL15-1, 11AL12-1, 13AL03-1, and 13AL01-1) were selected for zircon U-Pb dating and in situ Hf isotopic analysis. All analytical methods are described in Appendix A in the GSA Data Repository Item1, and the results from these samples are sum- marized in Tables 1 and 2 and in Data Repository Table DR1.

LA-ICP-MS Zircon U-Pb Dating

Zircons separated from our samples were 50–200 µm in length and Figure 4. Total alkali-silica (TAS) diagram (Le Maitre, 2002) of the studied exhibited regular or irregular oscillatory zoning with no apparent core-rim mafic and felsic intrusions. structure (Fig. 5). Their Th/U ratios were in the range of 0.1–1.2 (Data Repository Table DR1), consistent with those of magmatic zircons (Wil- liams et al., 1996). U-Pb dating of the four selected zircon samples all the Kuchahe intrusion (Fig. 7A). Compared to the Kuchahe intrusion, the yielded concordant results with weighted mean 206Pb/238U ages as follows: Leidashu intrusion exhibits higher REE and high field strength element 748 ± 4 Ma (1σ, mean square of weighted deviates [MSWD] = 0.4; n = 22) (HFSE) contents and lower Ba and Pb contents (Fig. 7B). All samples

for 11AL15–1 (22°53.90′Ν, 103°12.12′Ε), 750 ± 4 Ma (1σ, MSWD = are characterized by high alkali contents (K2O + Na2O = 7.05–9.44 wt%), 0.6; n = 22) for 11AL12–1 (22°50.65′Ν, 103°12.18′Ε), 750 ± 4.2 Ma with high 10,000*Ga/Al ratios (mostly greater than 2.6) as well as Zr + (1σ, MSWD = 1.9; n = 21) for 13AL03–1 (22°49.54′Ν, 103°11.29′Ε), Nb + Y + Ce greater than 350 ppm (Table 1).

and 751 ± 5 Ma (1σ, MSWD = 1.9; n = 19) for 13AL01–1 (22°50.95′Ν, The Leidashu intrusion exhibits negative εNd(t) values of –4.1 to –3.5 103°11.48′Ε; Fig. 5). These data suggest that the studied felsic and mafic (Table 2; Figs. 8A and 8B). Its 87Sr/86Sri values range from 0.7047 to intrusions have uniform mid-Neoproterozoic emplacement ages. 0.7061 (Table 2; Fig. 8A).

Bulk Geochemistry Qizanmi Intrusion

The Qizanmi intrusion is mafic, with low SiO2 contents of 48.2–49.7 T Kuchahe Intrusion wt% (Table 1). It has low TiO2 (0.21–0.56 wt%) and FeO (4.0–9.4 wt%)

The Kuchahe granite has high SiO2 contents of 73.91–75.18 wt% contents and relatively high MgO contents (6.3–9.6 wt%) and Mg# values (Table 1). All the samples are strongly peraluminous and are enriched in (Fig. 6B). All the samples are enriched in LREEs relative to HREEs, with

alkali contents (K2O + Na2O = 7.66–8.26 wt%), with alumina saturation positive Eu anomalies (Fig. 7A). In PM-normalized spidergrams, all the

index A/CNK [= molar Al2O3/(CaO + Na2O + K2O)] > 1.10 (Fig. 6A). samples exhibit notably negative Nb-Ta, La, Ce, Pr, Zr-Hf, and Ti anoma- These samples exhibit similar Mg# [= atomic Mg/(Mg + FeT)] (0.33–0.39) lies and positive Ba, K, Pb, Sr, and Eu anomalies (Fig. 7B). Compared to to experimental partial melts of metasedimentary rocks under continental mid-ocean-ridge basalt (MORB), the Qizanmi intrusion is more depleted pressure-temperature (P-T) conditions (Fig. 6B). In chondrite-normalized in REEs (except for La and Ce) and HFSEs, but more enriched in large rare earth element (REE) patterns, these rocks are enriched in light (L) ion lithophile elements (LILEs; Fig. 7B). REEs relative to heavy (H) REEs, with negative Eu anomalies (Fig. 7A). These mafic rocks have low initial87 Sr/86Sr values of 0.7040–0.7051

In primitive mantle (PM)–normalized spidergrams, they exhibit negative and positive εNd(t) values of +0.4 to +1.7 (Table 2; Fig. 8A). anomalies in Nb, Ta, La, Ce, Sr, Ba, and Ti (Fig. 7B).

The Kuchahe samples exhibit slightly negative εNd(t) values of –0.8 Zircon In Situ Hf Isotope to –0.2 (Table 2). Given that these sample have high Rb/Sr ratios (≥ 1), their initial Sr isotopic ratios were not analyzed. We carried out in situ Hf isotopic analyses on those zircons that were analyzed for the LA-ICP-MS zircon U-Pb dating. The results are shown Leidashu Intrusion in Data Repository Table DR1 (see footnote 1). The zircons from the

The Leidashu intrusion has intermediate compositions, with SiO2 Kuchahe intrusion have uniform initial εHf values of +3.7 to +4.8 (Data contents ranging from 60.76 to 63.89 wt% (Table 1). They plot in the Repository Table DR1; Fig. 8C). The Leidashu intrusion also has uni-

syenite, monzonite, and quartz monzonite fields in the diagram of SiO2 form initial εHf values, ranging from +0.6 to –1.5 (Data Repository Table

versus K2O + Na2O (Fig. 4). Most samples are metaluminous to weakly DR1; Fig. 8C). The zircons from the Qizanmi hornblende gabbro have

peraluminous and show similar Mg# values to the Kuchahe intrusion (Fig. positive initial εHf values of +4.5 to +6.0 (Data Repository Table DR1; 6). The Leidashu intrusion has similar REE and trace-element patterns to Figs. 8B and 8C).

1GSA Data Repository Item 2019129, Appendix A: descriptions of analytical methods, and Table DR1: LA-ICP-MS zircon U-Pb dating data and in-situ Hf isotopic data of the studied intrusions, is available at http://www.geosociety.org/datarepository/2019, or on request from [email protected].

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53 63 62 45 02 46 .9 .5 .8 .0 .1 .78 .2 .058 1. 1. 7. 1. 1. 1 1. 0.89 0.32 0.27 0.73 6.59 4.85 8.92 0.56 0.65 0.39 0.04 7 0.92 0.20 2.66 0.53 8.18 0.16 0.06 0.65 9.76 2.27 0.11 0.72 3.72 0.11 0.12 3.44 0.56 2.26 0.97 AL15 10 12 19 13 18 19 80.1 38.8 69.5 25.1 99.5 43.4 40 52.9 49.7 45.7 14 296 547 11 d melt

te -1 53 61 58 44 04 80 34 .8 .5 .5 .8 .8 .3 .2 1. 1. 7. 1. 1. 1. 1. 0.87 0.30 0.26 0.73 6.57 4.94 9.05 0.50 0.65 0.37 0.04 4 0.91 0.21 2.69 0.48 8.23 0.13 0.06 0.66 0.08 2.02 0.11 0.79 3.85 0.11 0.11 3.29 0.57 0.0570 2.22 0.97 11 37 74 10 13 18 19 66.4 25.5 20.0 99.5 38.9 40 49.9 49.7 53.4 AL15 14 269 559 11

36 13 10 03 97 09 .5 .9 .4 .7 .5 .026 1. 7. 1. 7. 1. 1. 0.83 0.28 0.20 0.73 0.99 3.45 0.73 5.29 2.77 8.62 0.53 0.62 0.50 0.06 2 0.82 0.06 2.49 0.44 0.07 8.15 0.06 8.13 0.44 8.51 2.02 0.12 0.80 6.03 0.14 0.12 3.16 0.21 0.29 2.91 17 97 12 13 18 70.6 38.4 26.3 98.2 27 60.5 49.4 29.6 that in the satura 21 293 578 6 3AL02- on to

90 rc i Qizanm 64 41 24 51 87 25 .5 .9 .2 .9 .9 .6 .6 1. 1. 7. 1. 1. 1. 0.91 0.34 0.26 0.82 4.01 0.84 5.76 2.77 4 9.64 0.31 0.59 5 0.57 0.02 0.89 0.06 3.46 0.37 8.53 0.04 8.46 0.07 4.56 0.61 9.85 0.13 0.92 5.89 0.15 2.03 0.14 3.91 0.49 0.01 0.22 2.57 17 27 57 41 12 18 18 45.7 36.8 98.3 33 48.2 73.6 OCK, CHINA 51 3AL02- 10 17 644

55 08 27 38 57 .0 .3 .9 7. 7. 1. 1. 1. 0.46 0.18 0.89 0.15 0.91 0.54 0.86 4.01 0.97 3.82 5 4.66 0.76 0.35 0.10 0.94 0.43 6.14 3.24 0.31 4.39 0.09 0.06 9.59 0.58 9.67 2.66 0.07 0.42 4.12 0.08 0.07 0.25 0.05 0.44 2.26 0.58 47 14 15 50.0 29 25.2 25.3 99.5 38 44.2 20.8 80.0 11 304 269 522 ANGTZE BL ANGTZE 41 3AL02- Y ,

8 5 9 04 18 01 16 26 16 .5 .34 .0 .6 1. 1. 1. 1. 1. 1. 0.49 0.1 0.86 0.1 0.89 0.56 0.85 4.1 8.21 4.12 6.18 7 4.39 0.74 0.33 0.10 0.55 5.8 4.56 0.28 4.46 0.06 4.06 0.07 6.34 5.68 0.56 0.06 0.43 2.95 0.06 0.07 0.27 0.05 0.29 2.73 0.63 11 41 31 AL02-31 16 89.4 29.1 23.2 99.6 37 49.3 24.0 40.4 USIONS 21 228 623 13

-1 5 51 39 28 92 23 65 83 .1 .1 .7 .6 .5 .9 .4 .4 .2 .6 .8 7. 1. 1. 1. 1. 1. 1. 4.20 8.62 2.1 4 4.49 2.67 2.44 0.36 5.74 4.07 8.52 2.48 0.49 0.86 9.88 4.68 0.93 0.57 3.85 2.89 0.10 2.68 0.57 2.69 0.83 0.24 6.60 2.51 4.54 3.22 17 17 17 97 61 41 10 12 16 14 12 93.7 70.1 99.6 25.2 65.5 60.8 AL14 17 839 404 492 836.6 636 11

-1 37 16 60 80 81 28 6 58 48 84 .1 .0

.5 .8 .1 .5 .6 .1 .7 7. 1. 1. 1. 1. 1. 1. 1. 1. AND QIZANMI INTR AND QIZANMI 3.91 6.79 9.14 7 4.46 2.97 2.46 0.35 6.35 4.04 9.11 2.60 0.52 7 0.79 6 8.28 6 2.86 0.55 3.52 2.72 0.09 2.74 0.55 2.85 0.82 0.23 8.48 3.39 3.66 3.34 11 con/melt is the ratio of Zr concentration (ppm) in zi 51 61 , 14 13 13 15 13 13 16 63.4 58.9 38.8 99.6 24.1 62.9 AL13 847. 11 12 31 51 334 12 11 SHU A

-1 e DZr zir 57 92 30 97 62 44 7 55 53 45 .9 .2 .6 .9 .6 7. 7. 7. 1. 1. 1. 1. 1. 1. 4.62 8.79 9.70 6.35 3.08 3.20 2.10 0.37 5.67 2.07 2.66 8.72 2.70 0.42 0.67 5 8.73 0.65 2.60 4.27 2.24 0.08 2.64 0.66 2.79 0.58 0.23 3.41 3.84 3.95 3.07 11 AL12 10 14 15 39.8 16 72.9 32.0 59 59.8 45.4 99.7 23.2 56.9 63.7 847. 10 349 332 481 11 12 7 2 6 8 4 .99 .75 .8 .69 .85 .7 .2 .7 .55 .69 .0 .09 1 1 1 1 1 1 1 5.52 0.02 0.32 2.03 5.3 8 3.1 2.58 3.97 6.50 0.28 3.72 2.1 2.1 3.1 2.77 0.46 2 0.89 9.43 0.65 3.52 0.53 4.91 3.24 0.08 2.61 0.7 0.63 0.1 4.51 3.39 4.44 4.7 11 11 17 41 21 1 1 1 1 1 58.6 64.8 83 54.7 24.9 98.9 23.6 56.9 63.9 con/melt]), wher 11 12 383 347 843.4 587 3AL03-5 Leidashu 13 1 THE KUCHAHE, LEID THE KUCHAHE,

6 8 17 .66 .43 .7 .27 .73 .81 .2 1 1 1 1 1. 1 4.48 8.28 9.1 2.07 0.7 5.4 4 4.73 2.09 2.37 8.1 6.02 0.28 4.26 8.8 9.32 2.0 9.72 2.27 0.45 0.84 0.6 0.57 3.99 0.44 3.96 2.69 0.09 2.69 0.62 2.92 0.77 0.24 5.73 3.46 4.37 4.55 57 17 1 1 1 1 69.4 64 52.8 44.5 24.9 99.5 07 24.5 69.8 62.2 13 1 452 392 850.0 650 3AL03-3 13 1 M + ln[DZr zir

76 16 .58 .38 .75 .0 .0 .78 .23 .22 .05 .67 .6 .1 .78 7. 7 1 7. 1 1 1 1 1 1 1 4.61 8.24 8.35 9.37 3.34 2.51 6.91 0.28 3.93 2.07 2.03 8.2 0.1 2.67 0.42 8.71 0.59 3.68 0.39 4.07 3.25 0.09 2.31 0.63 0.71 0.22 6.22 3.11 4.34 4.62 11 17 47 57 1 1 43.9 86.6 50.1 45.8 30.6 99.5 58.0 20.9 63.8 063 341 285 833.4 491 3AL03-2 1 1

3 8 16 .40 .26 .60 .9 .89 .94 .51 .57 .69 .4 .6 .44 .7 7. 1 1 ,900/(2.95 + 0.85 1 1 1 1 1 1 0.52 3.63 8.02 9.21 8.78 5.1 0.26 3.81 2.07 2.28 2.0 3.9 0.9 4.28 0.62 9 7 0.86 8.96 0.42 2.94 0.45 2.97 3.02 0.09 2.75 8.8 0.58 0.1 5.57 4.62 4.82 5.02 CE (PPM) ELEMENTS OF ELEMENTS CE (PPM) 11 27 71 61 1 1 1 44.7 1 03 52.2 52 33.9 26.2 39.7 30.9 99.5 1 31 14 353 835.5 523 3AL03-1 13 a)/(Al·Si). TRA

41 1 8 8 6 9 4 6 Tzr = 12 1- 74 14 18 ); .41 .5 .70 AND T 1. 1. 1 1. 1 0.37 2.29 0.82 4.27 0.67 3.63 0.70 3.90 8.3 5.1 0.78 2.1 6.63 0.35 2.05 5.77 3.1 2.3 6.34 9.91 3.96 4.1 0.65 5 4 0.34 2.77 1 0.35 0.39 0.84 2.45 0.47 0.03 2.31 4.1 4.3 0.72 0.1 0.05 4.50 3.7 3.29 17 7 1 1 1 45.6 22.6 96.5 20.5 26.7 34.6 99.6 32.5 10 16 18 547 759.1 3AL0 31 4 1- .9 .86 .09 .29 .64 .8 .42 .7 .21 .7 .1 .35 7 1 1 1 1 1 1 1 0.39 2.55 0.89 4.46 0.73 3.55 0.73 3.67 4.99 0.79 2.27 0.33 5.62 3.26 2.2 6.57 9.44 2 3.78 5.27 0.71 9 5 0.30 2.93 8 0.39 0.64 0.89 2.64 0.51 0.05 2.34 4.2 4.3 0.65 0.1 0.06 4.41 3.73 3.65 17 17 27 31 7 1 1 45.4 22.1 22.6 28.5 99.9 76 10 10 16 18 564 3AL0 MAJOR (WT%) MAJOR omic Mg/(Mg + Fe 21 uchahe 5 6 1- 19 K .20 .47 .22 .88 .2 .99 M = cation ratio (Na + K +2C 7 1 1 1 1 1. 0.34 2.1 0.75 3.91 0.64 3.56 0.63 3.86 9.7 5.52 0.82 0.95 0.38 5.50 3.66 5.6 6.72 8 9.9 3.98 4.20 0.85 9 0.37 3.64 8.8 7 0.33 0.47 0.99 2.39 0.59 0.04 2.52 4.1 0.56 0.1 0.08 2.72 4.47 3.69 2.96 11 1. ABLE 1 1 1 1 1 50.2 25.2 23 40.0 86.3 99.4 33.4 73.9 T 12 19 21 480 3AL0 782.1 Mg# = at 11

83), and 7 2 0 1- 12 01 16 .85 .05 .41 .62 .6 1 7. 1 1 1. 1 1. 0.29 0.64 3.39 0.56 3.00 0.59 3.26 5.2 4.31 9.4 5.09 0.96 3.62 0.39 4.23 3.88 4.0 6.39 9.07 3.21 9.8 9.1 0.42 8 2.1 6.3 8 0.30 2.95 7 0.28 0.38 0.88 6.1 2.02 0.36 0.02 2.38 0.54 4.0 0.1 0.09 3.20 4.46 2.82 17 1 1 1 1 1 39.7 04 20.4 99.5 75.2 11 11 3AL0 1 76 17 523 1 ison, 19 e+Y OI—loss on ignition. L e: 3 a 3 5 2 O 2 O I 2 O atson and Harr O O 2 tal O O eO/MgO 2 Not O 2 2 ample: 0,000*Ga/Al F Tm Er Ho Dy Tb Gd Eu Sm Nd Pr Ce La Cu Yb/T Ba Ni Y/Nb Co Cs Mg# Cr Sn U V Nb Th Sc Zr Pb Be Y1 Tl K Li Sr Ta Tzr (°C) MgO To Rb Hf M Lu Ca LO Ga Zr+Nb+C Yb Fe Al Fe P MnO Zn Na Ti 1 Location: SiO (W T S

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by guest Downloaded from http://pubs.geoscienceworld.org/gsa/lithosphere/article-pdf/11/3/348/4698799/348.pdf ZHENG LIU ET AL. | Mid-Neoproterozoic intrusions from the western Yangtze block RESEARCH 94 5-2 8282 2421 .4 .51 0.7071 0.000006 0.2293 0.7047 0.000006 0.14 1AL1 20 88 5-11 51 241 13 50 0. 0.707236 0.000006 0.20 0.7051 0.000003 0.14 0.51 1AL1 i Qizanm 6429 2628 .8 0.705096 0.000005 0.0205 0.7049 0.000005 0.18 0.51 3AL02-51 3031 2363 OCK, CHINA 70 1. AL02-31 0.704305 0.000005 0.0264 0.7040 0.000004 0.12 0.51 13 ANGTZE BL ANGTZE 74 -1 Y , 2232 40 19 .099502 AL14 0.71 0.000005 0.57 0.7061 0.000002 0.51 –3.6 11 SIONS 00 -1 992 6072 1 0817 0614 .71 .1 AL13 1. 0.000005 0.7047 0.000003 0.51 –4.1 11 39 RU INT AND QIZANMI -1 , 46 21 5250 335550 HU .71 AL12 0.000004 0.91 0.7055 0.000005 0.1 0.51 Leidashu AS –3.7 11 50 17 2043 2343 0.714 0.000006 0.7929 0.7057 0.000006 0.11 0.51 3AL03-3 –3.5 1 9 THE KUCHAHE, LEID THE KUCHAHE, 941 2097 24450 .3325 1 0.71 0.000005 0.7052 0.000002 0.1 0.51 3AL03-1 –3.6 1 1 -4 900 2274 0.000004 0.12 0.51 3AL01 –0.6 OPIC COMPONENTS OF OPIC COMPONENTS 31 1- 2269 24066 0.000002 0.1 0.51 3AL0 OT -Nd IS –0.2 Sr uchahe 42 21 K 1- ed. 2243 87 ABLE 2. ABLE yz T ——— ——— ——— ——— 0.000005 0.11 0.51 3AL0 –0.2 Figure 5. Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) zircon U-Pb concordance curves and typical curves U-Pb concordance zircon (LA-ICP-MS) coupled plasma–mass spectrometry Laser ablation–inductively 5. Figure MSWD—mean felsic intrusions. mafic and studied the from collected zircons of representative cathodoluminescence (CL) images deviates. of weighted square 11 1- 2267 29559 — — — — 0.000005 0.1 0.51 3AL0 –0.8 1 es sample not anal i ash indicat Nd Nd 4 D 4 Sr) Sr 14 Sr 14 e: 86 86 86 (t) σ σ Sr/ Sm/ Nd/ Not ample: Rb/ Sr/ 7 3 Nd 87 Location: 87 87 14 14 ±2 ( ±2 ε S

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by guest Downloaded from http://pubs.geoscienceworld.org/gsa/lithosphere/article-pdf/11/3/348/4698799/348.pdf ZHENG LIU ET AL. | Mid-Neoproterozoic intrusions from the western Yangtze block RESEARCH

Figure 7. (A) Chondrite-normalized (McDonough and Sun, 1995) rare earth element (REE) patterns and (B) primitive mantle–normalized (McDonough and Sun, 1995) trace-element patterns for the studied mafic and felsic

Figure 6. (A) A/CNK vs. A/NK classification diagram and (B) SiO2 vs. Mg# intrusions. MORB—mid-ocean-ridge basalt; OIB—oceanic-island basalt. plot for the studied mafic and felsic intrusions. The fields of some experimental melts are also shown: vapor-absent partial melts  of a two-mica schist (plagioclase-poor natural metapelitic rock) at 7–13 kbar, 825–1075 °C Kuchahe intrusion is not a highly fractionated granite (Fig. 10). Taken (Patiño Douce and Johnston, 1991);  of a biotite gneiss (plagioclase-rich synthetic metapsammitic rock) at 3–15 kbar, 875–1000 °C (Patiño Douce and together, the geochemical signatures suggest that the Kuchahe intrusion Beard, 1995);  of a quartz amphibolite (plagioclase-rich synthetic rock) at can be classified as an S-type granite (Barbarin, 1996; Sylvester, 1998; 3–15 kbar, 875–1000 °C (Patiño Douce and Beard, 1995);  of a metavolca- Jiang and Zhu, 2017). Several models have been formulated with regard niclastic rock (plagioclase-rich natural metapsammitic rock) at 10–20 kbar, to the origin of peraluminous S-type magmas: 850–1050 °C (Skjerlie and Johnston, 1996). Also shown are A-type melts (1) Some peraluminous granites were produced by fractional crystal- obtained from experimental studies on dehydration melting of calc-alkaline lization (FC) of metaluminous magmas in closed systems, with fraction- tonalite and granodiorite at 4 kbar, 950 °C (Patiño Douce, 1997). ation of amphibole and clinopyroxene (Cawthorn and Brown, 1976). They are a minor component of granitoid suites that are dominantly metaluminous. For the Kuchahe intrusion, the associated metaluminous rocks are DISCUSSION not exposed in the studied area. The significant fractionation of amphibole would produce positive Eu anomalies and result in decreasing Dy/

Petrogenesis Yb and increasing La/Yb with increasing SiO2. The presence of concave REE patterns is diagnostic of prominent amphibole fractionation. We do Kuchahe Intrusion not observe these geochemical signatures (Fig. 7A). Thus, the Kuchahe The Kuchahe intrusion consists mainly of leucogranite and contains a intrusion was not derived by the FC model. t small amount of biotite (<5%), with low FeO + MgO + TiO2 contents (<2 (2) Experimental studies demonstrate that partial melting of quartz wt%; Fig. 9). It is strongly peraluminous with high A/CNK values (>1.1; amphibolite at P > 10 kbar can produce strongly peraluminous granitic

Fig. 6A). All samples contain muscovite, which is highly aluminous. The magmas (Fig. 6A). Sylvester (1998) suggested that the CaO/Na2O ratio muscovites exhibit subhedral shapes. They are not enclosed by or enclos- is a better indicator to constrain the sedimentary source component of ing K-feldspar or cordierite, which can break down to form muscovite strongly peraluminous granites. This is because the ratio is dominantly through subsolidus alteration. All the petrographic criteria indicate that the controlled by the plagioclase/clay ratio of the sedimentary source. Com- muscovite in the Kuchahe intrusion exists as a primary magmatic phase pared to strongly peraluminous melts derived from plagioclase-poor, clay- (Barbarin, 1996). The relatively low FeOT/MgO ratios indicate that the rich sources (pelites), those originating from plagioclase-rich, clay-poor

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87 86 t Figure 8. (A) Initial Sr/ Sr vs. εNd(t) (after J.H. Zhao et al., 2008a). (B) Age vs. εHf(t). (C) Initial εNd(t) Figure 9. (A) SiO2 vs. CaO/Na2O, (B) SiO2 vs. FeO

vs. εHf(t) (modified after Vervoort et al., 1999) for the studied mafic and felsic intrusions. In A, initial + MgO + TiO2 and (C) Pb vs. Ba. In A and B, the Sr-Nd isotopic data from 810–764 Ma granitoids from the Ailaoshan tectonic zone are also shown for fields of some experimental melts are also shown comparison (data source: Wang et al., 2016b). In B, initial in situ zircon Hf isotopic data of 799–753 Ma and the data sources are same as in Figure 6. In C, granitoids from the Ailaoshan tectonic zone are also shown for comparison (data source: Qi et al., the fields of Lachlan, Variscan, and primary low- 2014). In C, data for island-arc volcanics, mid-ocean-ridge basalt (MORB), and continental crustal sam- temperature S-type granites are also shown and ple are from Vervoort et al. (1999). OIB—oceanic-island basalt; CHUR—chondritic uniform reservoir. data are from Finger and Schiller (2012).

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large amounts of Pb. The resulting restite assemblage (Qz + Bt + Sil ± Pl ± Grt ± Kfs) can retain minor amounts of Pb but much Ba because both biotite and K-feldspar in the restite contain very high Ba contents (Finger and Schiller, 2012). Finger and Schiller (2012) also proposed that low-T and low-degree anatectic events, such as muscovite-dehydration melting or fluid-present melting of muscovite, could strongly enrich Pb relative to Ba in the resultant partial melts. In contrast, during higher-T and larger- degree partial melting, breakdown of biotite will lead to less enrichment of Pb and less depletion of Ba. The Kuchahe leucogranites have relatively low Pb contents at a given Ba content (Fig. 9C). All samples are similar to the high-T S-type granites from the Lachlan fold belt and the European Variscides, which have been regarded as products of biotite breakdown reactions (Clemens and Wall, 1981; Chappell et al., 2004; Finger and Schiller, 2012). We thus conclude that the Kuchahe intrusion was produced by higher-T and larger-partial melting reactions. This is also reconciled with the fact that the zircon saturation temperatures of the Kuchahe samples are distributed between 759 °C and 782 °C (Fig. 10D). The samples from the Kuchahe intrusion have similar Mg# as the experimental melts (Fig. 6B), reflecting insignificant mantle contribution. This speculation is supported by their extremely low compatible element contents (Cr = 1.62–2.05 ppm, Ni = 0.78–1.05 ppm, and V = 6.34–6.72 ppm; Table 1). Furthermore, basalt mixing will lead to a marked increase t in FeO + MgO + TiO2 and a marked decrease in SiO2 contents (Fig. 9B). t The low FeO + MgO +TiO2 and high SiO2 contents also rule out a mixing

Figure 10. (A) 10,000*Ga/Al vs. Zr (ppm) discriminant diagram (Eby, 1990); process. These samples have high εNd(t) of -0.8 to -0.2 and positive εHf(t) (B) Zr + Nb + Ce + Y (ppm) vs. FeOT/MgO discriminant diagram; (C) Y/Nb of +3.7 to +4.8 (Fig. 8). However, as discussed already, these isotopic vs. Yb/Ta (Eby, 1992); (D) M = (Na + K + 2Ca)/(Al·Si) vs. Zr (ppm) (Jiang signatures cannot be attributed to direct input of mantle-derived magmas. et al., 2011) for the studied mafic and felsic intrusions. FG—fractionated The Mesoproterozoic Hf model ages of 1.18–1.12 Ga indicate that the I-type granitoids; OGT—I-, S-, and M-type granitoids; OIB—oceanic-island basalt; IAB—island-arc basalt. Kuchahe intrusion was associated with late Mesoproterozoic juvenile crust. The enrichment in LREEs and LILEs relative to HFSEs and HREEs is a common feature of arc magmas (Taylor and McLennan, 1995). The arc- like trace-element patterns of the Kuchahe samples were likely inherited

sources (e.g., psammites) have higher CaO/Na2O ratios (> 0.3). In amphib- from preexisting Mesoproterozoic arc magmatic rocks. The ca. 1066 Ma olites, amphibole and plagioclase are dominant phases. They have high (based on SHRIMP zircon U-Pb dating) Shimian ophiolite supports the

CaO and Na2O contents and CaO/Na2O ratios. Thus, we suggest that inference that a late Mesoproterozoic arc system had developed along the strongly peraluminous melts derived from amphibolites also have high western margin of the Yangtze block (Hu et al., 2017). The Mesoprotero-

CaO/Na2O ratios. This is supported by the experimental data on a quartz zoic juvenile arc crust is further evidenced by the positive Nd-Hf initial amphibolite (Patiño Douce and Beard, 1995; Fig. 9A). However, the isotopic components in other Neoproterozoic magmatic rocks distributed

extremely low CaO/Na2O ratios of our samples preclude amphibolites along the same region (X.H. Li et al., 2005; X.F. Zhao et al., 2008b; Zhao as their source. and Zhou, 2008; Lai et al., 2015; Xu et al., 2016). The weathering and (3) The consensus view is that strongly peraluminous granitic magmas erosion of the Mesoproterozoic arc crust could then have generated the are most easily produced by partial melting of metasedimentary rocks juvenile arc–derived sediments that were subsequently buried to form the (e.g., Barbarin, 1996; Sylvester, 1998; Jiang et al., 2011; Jiang and Zhu, metapelitic source of the Kuchahe intrusion. Similarly, the Neoproterozoic 2017). The initial Nd-Hf isotopic data of the Kuchahe samples also plot Xucun (ca. 823 Ma), Shi’ershan (ca. 779 Ma), and Jiuling (ca. 819 Ma) in the field of continental sediments (Fig. 8). Experimental studies on granites from the eastern part of the Jiangnan orogen have positive zircon

metagraywackes and metapelites suggest that the resulting partial melts εHf(t) values, with juvenile Mesoproterozoic Hf model ages (Zheng et al.,

are dominantly peraluminous (Fig. 6A). The low CaO/Na2O ratios of our 2008; X.L. Wang et al., 2013c). They have been interpreted as products samples mirror those of experimental melts of a natural metapelitic rock of reworking of late Mesoproterozoic juvenile crust (Zheng et al., 2008; (Patiño Douce and Johnston, 1991). This implies that the Kuchahe intru- X.L. Wang et al., 2013c). To sum up, the Kuchahe intrusion was likely sion might have originated from a metapelitic source (Fig. 9A). Previous produced by biotite-dehydration melting of a metapelitic source that had studies have demonstrated that leucogranitic melts are generally formed been formed by the burial of juvenile arc–derived sediments. by the following melting reactions, including: (1) 9 muscovite (Ms) +

15 plagioclase (Pl) + 7 quartz (Qtz) + xH2O = 31 Melt (fluid-present Leidashu Intrusion melting at < 750 °C), (2) 22 Ms + 7 Pl + 8 Qtz = 5 K-feldspar (Kfs) + 5 The Leidashu intrusion consists of monzonite, quartz monzonite, and aluminosilicate (Als) +2 biotite (Bt) + 25 Melt (fluid-absent melting at syenite. Petrographically, these samples contain xenomorphic amphibole

680–770 °C), and (3) Bt + Als + Pl + Qtz = garnet (Grt) + Kfs + Melt and interstitial biotite. Geochemically, they are enriched in alkalis (K2O

(fluid-absent melting at higher temperature (760–830 °C; Inger and Har- + Na2O = 7.05–7.83 wt%), REEs (except for Eu), and HFSEs, but they ris, 1993; Patiño Douce and Harris, 1998; Vielzeuf and Holloway, 1988; are depleted in Ba, Sr, and Eu. All samples exhibit high zircon saturation Knesel and Davidson, 2002). In amphibolite-facies metapelites, Pb is temperatures (833–850 °C), and elevated 10,000*Ga/Al ratios (mostly dominantly enriched in muscovite and then its breakdown can release >2.6), as well as high Zr + Nb + Y + Ce contents (> 350 ppm), which are

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indicative of A-type granitoids (Fig. 10). Currently, two main petrogenetic Leidashu intrusion and the earlier Neoproterozoic granodiorites (810–753 models have been proposed for the formation of A-type granitoids: (1) Ma) from the Ailaoshan tectonic zone (Figs. 8A and 8B). Compared to derivation from transitional to alkaline oceanic-island basalt (OIB)–like the A-type melts from experiments (Patiño Douce, 1997), the Leidashu t mafic and intermediate magmas with or without significant crustal con- samples have lower SiO2 and higher Mg# and CaO/Na2O, as well as FeO +

tamination (e.g., Bonin and Giret, 1990; Turner et al., 1992; Eby, 1992; MgO + TiO2, indicating mixing of basaltic magmas (Figs. 6 and 9). Fur- Bonin, 2007), or (2) partial melting of specific crustal sources, such as thermore, the high HREE (Yb = 2.97–4.91 ppm) and Y (38.78–54.71 ppm) residual meta-igneous (granulitic) rocks, newly underplated crust, and contents, coupled with relatively flat HREE patterns (Fig. 7A), suggest that calc-alkaline granitoids (e.g., Collins et al., 1982; Creaser et al., 1991; garnet was not a residual phase after partial melting. The markedly nega- Eby, 1992; Shellnutt and Zhou, 2007; Patiño Douce, 1997). Furthermore, tive Eu and Sr anomalies support the presence of plagioclase as a residual Poitrasson et al. (1995) proposed that mantle-derived magmas mixed with mineral phase (Fig. 7). Altogether, these geochemical signatures also lend a crustal source could also produce A-type magmas. credence to a relatively shallow crustal source. The high zircon saturation Eby (1990) suggested that any specific suite of A-type granitoid suites temperature (833–850 °C) requires additional heat from the mantle for has a relatively constant Y/Nb ratio, and the ratio is insignificantly dis- crustal melting (Fig. 10D). The occurrence of the coeval basic intrusion turbed by most magmatic processes such as fractional crystallization and (Qizanmi) suggests that crustal melting might have been triggered by the

partial melting. Generally, A1-type melts, derived from an OIB-like mantle intrusion of mantle-derived magmas. Based on all the evidence presented

source, exhibit low Y/Nb ratios (<1.2), whereas A2-type melts, coming here, the Leidashu intrusion was likely derived through partial melting of from a crustal source, have relatively high Y/Nb ratios (>1.2; Eby, 1990, earlier Neoproterozoic granodiorites in the middle crust (~15 km), with 1992). In this study, all the Leidashu samples have high Y/Nb ratios of mixing of basaltic magmas.

1.5–3.2, consistent with those of A2-type granitoids (Fig. 10C), indicating a crustal source. The crustal source is also inferred from the negative Qizanmi Intrusion

εNd(t) values of −4.1 to -3.5 and negative Nb-Ta-Ti anomalies (Fig. 7). The All the samples from the Qizanmi intrusion have basaltic components,

contrasting Sr-Nd-Hf isotopic components between the Leidashu intrusion with low SiO2 contents that range from 48.2 to 49.7 wt% (Table 1). The and the coeval Qizanmi mafic intrusion also rule out a mantle source (Fig. intrusion exhibits relatively constant bulk Sr-Nd isotopic ratios, implying 8). More importantly, incompatible elements of the Qizanmi intrusion are that crustal contamination was insignificant. Furthermore, the absence extremely depleted, especially HFSEs, which are even lower than MORB. of a negative correlation between incompatible trace-element ratio (Th/

Such depleted melts cannot be reconciled with high absolute abundances Nb) and εNd(t) argues against significant contamination. The insignificant of HFSEs of A-type melts (Fig. 7B). In addition, differentiation of alkali crustal contamination is also indicated by the markedly negative Zr-Hf basalts with high incompatible element contents is more likely to form anomalies in the spider diagrams (Fig. 7B). peralkaline melts rather than metaluminous A-type granites (e.g., Bonin, The Qizanmi intrusion has variable Mg# (0.59–0.76 wt%), FeOT 1986; Shellnutt and Zhou, 2007). Thus, we prefer the interpretation that (4.0–9.4 wt%), MgO (6.3–9.6 wt%), and compatible element contents the Leidashu intrusion mainly originated from a crustal source. (Cr = 66–293 ppm; Ni = 71–304 ppm), which suggest differentiation of Most of the Leidashu samples are metaluminous to weakly peralumi- mafic minerals. Meanwhile, the positive Eu and Sr anomalies provide nous, inconsistent with the strongly peraluminous partial melts of metasedi- evidence for accumulation of plagioclase (Fig. 7A). Relative to MORB, mentary rocks (Fig. 6A). In addition, the Leidashu intrusion has different the lower REE (except for La and Ce) and HFSE contents of the Qizanmi elemental and isotopic signatures from the Kuchahe intrusion (Figs. 6–9). intrusion can be also attributed to accumulation of plagioclase, because Based on these observations, we conclude that the Leidashu intrusion was these elements are incompatible in plagioclase. not derived from a metasedimentary source. Several (meta-)igneous sources Incompatible-element ratios and Sr-Nd-Hf isotopic ratios are not gen- have been proposed for A-type granitoids, including: newly underplated erally disturbed by fractionation crystallization and mineral accumula- crust (Jahn et al., 2000; Shellnutt and Zhou, 2007), residual meta-igneous tion. Thus, these ratios can be used to constrain the nature of the source. (granulitic) rocks (Collins et al., 1982), and calc-alkaline granitoids (tonal- All the samples are evidently enriched in LREEs relative to HREEs (Fig. 87 86 ite and granodiorite; Creaser et al., 1991). The newly underplated crust 7A), with high La/Ybn ratios between 2.16 and 6.90. Also, the Sr/ Sri

refers to those igneous rocks formed by magmatic underplating. They have (0.7040–0.7051) ratios and εNd(t) (+0.4 to +1.7) values of these samples short “crustal residence times” and exhibit PM-like isotopic signatures, are found to differ significantly from those of MORB (Fig. 8A). The 87 86 with positive εNd(t) and εHf(t) and low Sr/ Sri (Arndt, 2013). Partial melts low HFSEs contents and Nb-Ta, La-Ce, Zr-Hf, and Ti depletions in the derived from a crustal source will inherit its isotopic component. However, PM-normalized spidergrams are also not reconciled with OIB values the crust-like isotopic signatures of the Leidashu intrusion suggest that it (Sun and McDonough, 1989). The relative depletion of these HFSEs was unlikely to have resulted from a newly underplated crust (Figs. 8A has been interpreted as an indicator of a subduction process (Thirlwall and 8B). Alternatively, Collins et al. (1982) proposed that A-type granites et al., 1994). The crust-like geochemical characteristics of our samples, might originate from a refractory and residual granulitic source that had such as their negative Nb-Ta-Ti and Zr-Hf values, as well as positive Pb previously undergone magmatic extraction. Experimental studies have anomalies (Fig. 7B), indicate a subcontinental lithospheric mantle source revealed that refractory granulitic residues produced by partial melting of that had been modified by subducted slab–released components (fluids or both metasedimentary and meta-igneous rocks are markedly depleted in melts). Furthermore, both HFSEs and REEs (e.g., Th, Y, Zr, and Nb) are

Na2O + K2O relative to Al2O3 (Patiño Douce and Beard, 1995). In addi- more immobile in fluids than in melts (Kepezhinskas et al., 1997; Zhao tion, it was argued that remelting of the residues could not yield A-type and Zhou, 2007). Consequently, the La-Ce and Zr-Hf depletions in the

granitic rocks, as the latter have high (Na2O + K2O)/Al2O3 ratios (Creaser trace-elements patterns demonstrate the introduction of slab-derived flu- et al., 1991). Meanwhile, experimental and modeling results have indi- ids rather than melts into the overlying lithospheric mantle source (Fig. cated that A-type granites could be derived by partial melting of tonalitic 7B; Zhao and Zhou, 2007). This is also compatible with the presence of to granodioritic igneous rocks at both low pressure (P = 4 kbar) and high abundant hornblende (water-bearing mineral) in the mineral assemblages. temperature (T = 950 °C; Creaser et al., 1991; Patiño Douce, 1997). This REEs ratios are useful for constraining formation depth of basaltic

model is bolstered by the initial Sr-Nd-Hf isotopic similarity between the magmas (McKenzie and O’Nions, 1991). In this study, the low (Dy/Yb)n

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ratios (1.30–1.43), coupled with flat HREEs patterns (Fig. 7A), suggested Given that an arc system was developing along the western Yangtze block that the Qizanmi basaltic rocks likely originated from the spinel stability during the mid-Neoproterozoic, the Leidashu intrusion was most likely field (Miller et al., 1999; Liu et al., 2015). As further evidence, the diagram emplaced in a back-arc setting, in response to the oceanic subduction.

of (La/Sm)n versus (Sm/Yb)n also demonstrates that <15% nonmodal equi- The Kuchahe intrusion has strongly peraluminous leucogranites and con- librium melting of spinel lherzolite + minor garnet lherzolite can produce tains primary muscovite that is highly aluminous. In general, peraluminous the Qizanmi melts (Fig. 11). This reflects a melting depth located in the granitoids can be divided into two groups based on mineralogy, rock type, field ranging from spinel into the spinel-garnet transition zone (~60–80 and petrogenesis, including muscovite-bearing peraluminous granitoids km; Robinson and Wood, 1998). Such a shallow depth is reconciled with (MPGs) and biotite-rich, cordierite-bearing peraluminous granitoids (CPGs; the lithospheric source. Taken together, the Qizanmi intrusion was likely Barbarin, 1996). MPGs contain primary muscovite and consist of monzo- generated by partial melting of a shallow enriched lithospheric mantle granites and leucogranites. Evidently, the Kuchahe intrusion belongs to source that had been modified by slab-released fluids, with accumulation MPGs. MPGs have been postulated to result from “wet” anatexis of crustal of plagioclase and fractionation of mafic minerals. rocks, which is associated with major crustal shear or overthrust structures in an orogenic belt (Barbarin, 1996). Transcurrent thrusts and shear zones Tectonic Environment formed during continental collision can provide not only heat to initiate melting, but also water to enhance it. They are the best places to generate The Qizanmi intrusion is depleted in incompatible elements and exhib- MPGs. Similarly, MPGs from the Qinling orogen (central China) and the its negative Nb-Ta-Ti anomalies, which contradict the geochemical sig- Western Kunlun orogen (NW China) were emplaced during a syncollisional natures of a plume-related OIB (Fig. 7B). Instead, its mantle source had orogenic event that temporally followed arc magmatism (Jiang et al., 2010, been strongly modified by subducted slab–released fluids. Similarly, the 2013). Recently, Jiang et al. (2011) and Jiang and Zhu (2017) identified Panzhihua (738 ± 23 Ma) and Gaojiacun (825 ± 12 Ma) hornblende gab- four late Mesozoic MPGs (Ehu, Xinfengjie, Jiangbei, and Dadu intrusions) bros in the western Yangtze block have also been identified by Zhao and from the South China block, which were generated in a back-arc or arc Zhou (2007) and Zhu et al. (2006). Furthermore, the occurrence of the setting associated with the paleo-Pacific subduction, indicating that MPGs Neoproterozoic (760–745 Ma) adakites from the Kangding-Panxi area, are not restricted to orogenic belts. As mentioned above, the Kuchahe intru- sourced from an oceanic slab, indicates that modified lithospheric mantle sion was formed by biotite-dehydration melting of a metapelitic source at was associated with the coeval subduction rather than ancient subduction relatively high temperature (760–830 °C). The high-T anatexis is consistent (Zhou et al., 2006a, 2006b; Zhao and Zhou, 2007). with a tensional environment in a back-arc basin. The back-arc setting is The Leidashu intrusion shares geochemical affinities with A-type also supported by the volcano-sedimentary sequence of the Yanbian Group, granitoids. Similarly, the ca. 780 Ma Mianning granite from the western containing shale, chert, and volcaniclastic sandstone (Zhou et al., 2006a, Yangtze block also exhibits A-type geochemical characteristics (Huang 2006b; Zhao and Zhou, 2007). Taken together, these results prompted us to et al., 2008). A-type rocks are generally emplaced in extensional tectonic conclude that our investigated intrusions were also emplaced in a back-arc environments such as a continental rift, within-plate setting, postorogenic setting. Ongoing extension triggered by the slab roll-back would lead to or back-arc setting, generally postdating calc-alkaline arc magmatism, the progressive thinning of lithosphere, and the subsequent asthenospheric which occurs mainly at active continental margins (Eby, 1990, 1992). upwelling would initiate partial melting of the overlying lithospheric mantle The high zircon saturation temperatures (833–850 °C) coupled with shal- and crustal rocks, leading to the formation of the Qizanmi hornblende gab- low depth of the crustal source also indicate an extensional environment. bros as well as the Kuchahe and Leidashu felsic intrusions.

Figure 11. (La/Sm)N vs. (Sm/Yb)N diagram for the Qizanmi intrusion. The nonmodal batch melting modeling curves of a spinel-bearing lherzolite (solid curve) and garnet- bearing lherzolite (dotted curve) are also shown. Modal composition of the spinel-bearing lherzolite: olivine (55%), orthopyroxene (15%), clinopyroxene (28%), and spinel (Spl; 2%). The garnet-bearing lherzolite contains 2%, 4%, and 7% garnet (Grt) in modal percent. Detailed calculations are described in Jourdan et al. (2007). The trace-element contents have been chondrite-normalized (McDonough and Sun, 1995). The associated partition coefficients are cited from McKenzie and O’Nions (1991).

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Location of the South China Block in Rodinia sedimentary sequence positions (Jiang et al., 2003). These similarities indicate that the Yangtze block may have been located close to NW India Currently, two contrasting reconstruction models, the internal model during the late Neoproterozoic. (e.g., Z.X. Li et al., 2002b; Z.X. Li et al., 2008) and the external model In contrast, the internal model requires the involvement of the South (e.g., Zhou et al., 2002; Wang et al., 2006; Cawood et al., 2013, 2017; Zhao, China block in the assembly of Laurentia and Australia-Antarctica from 2015), have been formulated to constrain the paleogeographic position of 1.1 Ga to 0.9 Ga, and it considers the Neoproterozoic magmatic rocks the South China block in Rodinia. The two models are based on diverg- (<0.9 Ga) as products of the activities of a superplume that caused the ing interpretations on the origin of the Neoproterozoic magmatic rocks Rodinia supercontinent to disintegrate (e.g., Z.X. Li et al., 2008). Based (<0.9 Ga) in the Yangtze block. In addition, the internal model, unlike on stratigraphic correlations and tectonic analysis, the internal model sug- the alternative, considers the South China block as a key link between gests that the Yangtze block of the South China block could have been a Laurentia and Australia. In contrast, the external model indicates a close continental fragment between Australian-Antarctica and Laurentia during link among India, South China, and Australia (e.g., Zhou et al., 2002; J.H. the late Mesoproterozoic to early Neoproterozoic (from 1.1 Ga to 0.9 Ga) Zhao et al., 2008a; X.L. Wang et al., 2006, 2008, 2013c, 2014; Cawood assembly of the Rodinia (Z.X. Li et al., 1995, 2002b). In addition, the et al., 2013, 2017; Zhao, 2015). Cathaysia block of the South China block has been interpreted as a part In this work, detailed geochemical data indicate that the Qizanmi horn- of a continental strip adjoining western Laurentia before being attached blende gabbros were most likely derived from an enriched lithospheric to the Yangtze block at ca. 1.0–0.9 Ga. The internal model indicates that mantle source infiltrated by oceanic slab–released fluids. Furthermore, the Yangtze block had undergone marked oceanic subduction to partake the association of A-type (Leidashu) and S-type (Kuchahe) intrusions in the final assembly of Rodinia. However, the internal model predicts reflects roll-back of the oceanic slab (Fig. 12). All the investigated mafic abundant Grenvillian (>0.9 Ga) arc magmatism in the Yangtze block, and felsic intrusions (ca. 750 Ma) were emplaced in a back-arc setting which is contradicted by what we observed in the current study (Fig. 13A). during lithospheric extension. Similarly, a magmatic peak (755–748 Ma) In general, a superplume is composed of a cluster of plumes (Ernst and in the Seychelles (western Greater India) has been identified by Tucker et Buchan, 2002). As demonstrated by Ernst and Buchan (2002, 2003), it is al. (2001), producing granites, quartz diorites, and dolerites. They were difficult to identify ancient plume clusters due to limited understanding also likely emplaced in a back-arc setting, in response to an ancient of paleocontinental reconstructions. The most key evidence for recogniz- oceanic subduction event (Tucker et al., 2001). These coeval magmatic ing a mantle plume is the presence of a large igneous province, which activities indicate a setting for South China adjacent to India during the consists mainly of a radiating system of basaltic sills, dikes, layered mid-Neoproterozoic. Furthermore, the Neoproterozoic magmatic rocks intrusions, and small volumes of granitic rocks in the Proterozoic due exposed in the Madagascar, Seychelles, and NW India exhibit similar to the erosion of flood basalts (Ernst and Buchan, 2003). Most of these emplacement ages (850–700 Ma) and geochemical characteristics to basaltic rocks exhibit OIB-like geochemical signatures, including positive the ones from the western and northwestern Yangtze block (e.g., Tucker Nb-Ta anomalies and enrichment in incompatible-element contents. In et al., 2001, 2014; Ashwal et al., 2002; Archibald et al., 2016). All the addition, those granites associated with a mantle plume exhibit generally magmatic rocks are considered to have made up a continuous continen- A-type affinities (Eby, 1990, 1992). However, Neoproterozoic igneous tal arc (Zhou et al., 2006a, 2006b; Cawood et al., 2017). By analyzing rocks exposed around the Yangtze block are dominated by granitoids Early Cambrian small shelly fossils from Yangtze, Tarim, Iran, India, with arc-like geochemical affinities. Moreover, these granitoids are domi- Kazakhstan, Australia, West Avalonia, and Siberia, Steiner et al. (2007) nantly I-type and S-type rocks, and secondarily A-type rocks (Fig. 13B; recognized close relationships among the Tarim, Iran, India, and Yangtze Table 3). Although some mafic rocks exhibit some similar geochemical blocks. Paleomagnetic data also arranged the South China block at the signatures (enrichment in both LILEs and HFSEs) to continental flood India-Australia edge (Powell and Pisarevsky, 2002; Yang et al., 2004). basalts (X.H. Li et al., 2003a; Zhu et al., 2006, 2008; Zhou et al., 2018), In addition, latest Neoproterozoic rocks from the Lesser Himalaya (NW they have markedly negative Nb-Ta anomalies, which are diagnostic of India) and Yangtze block exhibit remarkably similar carbonate platform a subduction process. We thus theorize that the mid-Neoproterozoic (ca. architecture, facies assemblages, and karstic unconformities at equivalent 750 Ma) western Yangtze was a convergent continental margin rather

Figure 12. Cartoon showing magmatic emplacement. Slab roll-back triggered lithospheric thinning and asthenospheric upwelling, followed by the emplacement of the Qizanmi (hornblende gabbro), Leidashu (A-type), and Kuchahe (S-type) intrusions. LILEs—large ion lithophile elements.

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(3) All the three intrusions were formed in a back-arc basin in response to subducted slab roll-back. (4) The mid-Neoproterozoic subduction process suggests that the South China block was located on the margin rather than in the interior of the Rodinia supercontinent.

ACKNOWLEDGMENTS This study was financially supported by the National Natural Science Foundation of China (grant 41703022), Fundamental Research Funds for the Central Universities (lzujbky-2018–52), the Plateau Mountain Ecology and Earth’s Environment Discipline Construction Project (grants C176240107), and the Joint Foundation Project between Yunnan Science and Technology Department and Yunnan University (grants C176240210019). We are grateful to Lithosphere Science Editor Laurent Godin and two anonymous reviewers for their thoughtful reviews and constructive comments.

REFERENCES CITED Ao, W.H., Zhang, Y.K., Zhang, R.Y., Zhao, Y., and Sun, Y., 2014, Neoproterozoic crustal accretion of the northern margin of the Yangtze plate: Constraints from geochemical characteristics, LA-ICP-MS zircon U-Pb chronology and Hf isotopic compositions of trondhjemite from Zushidian area, Hannan region: Geological Review (Dizhi Lunping), v. 60, p. 1393–1408. Archibald, D.B., Collins, A.S., Foden, J.D., Payne, J.L., Holden, P., Razakamanana, T., Waele, B.D., Thomas, R.J., and Pitfield, P.E.J., 2016, Genesis of the Tonian Imorona-Itsindro magmatic suite in central Madagascar: Insights from U-Pb, oxygen and hafnium isotopes in zircon: Precambrian Research, v. 281, p. 312–337, https://doi .org /10 .1016 /j .precamres .2016 .05 .014 . Arndt, N.T., 2013, Formation and evolution of the continental crust: Geochemical Perspectives, v. 2, p. 405–533, https://doi.org/10.7185/geochempersp.2.3. Ashwal, L.D., Demaiffe, D., and Torsvik, T.H., 2002, Petrogenesis of Neoproterozoic granitoids and related rocks from the Seychelles: The case for an Andean-type arc origin: Journal of Petrology, v. 43, p. 45–83, https://doi.org/10.1093/petrology/43.1.45. Barbarin, B., 1996, Genesis of the two main types of peraluminous granitoids: Geology, v. 24, p. 295–298, https://doi.org/10.1130/0091-7613(1996)024<0295:GOTTMT>2.3.CO;2. Bonin, B., 1986, Ring Complexes and Anorogenic Magmatism: London, North Oxford Aca- demic, 188 p. Bonin, B., 2007, A-type granites and related rocks: Evolution of a concept, problems and pros- pects: Lithos, v. 97, p. 1–29, https://doi.org/10.1016/j.lithos.2006.12.007. Bonin, B., and Giret, A., 1990, Plutonic alkaline series: Daly gap and intermediate compositions for liquids filling up crustal magma chambers: Schweizerische Mineralogische and Petrographische Mitteilungen, v. 70, p. 175–187. Cai, Y.F., Wang, Y.J., Cawood, P.A., Zhang, Y.Z., and Zhang, A.M., 2015, Neoproterozoic crustal growth of the southern Yangtze block: Geochemical and zircon U-Pb geochronological and Lu-Hf isotopic evidence of Neoproterozoic diorite from the Ailaoshan zone: Precambrian Figure 13. (A) Age distribution of late Mesoproterozoic to Neoproterozoic Research, v. 266, p. 137–149, https://doi.org/10.1016/j.precamres.2015.05.008. magmatic rocks in the Yangtze block. (B) Histogram of A-, I-, and S-type fel- Cawood, P.A., Wang, Y.J., Xu, Y.J., Zhao, G.C., 2013, Locating South China in Rodinia and Gondwana: A fragment of greater India lithosphere?: Geology, v. 41, p. 903–906, https:// sic rocks from the western Yangtze block. Compiled data are from Greentree doi.org/10.1130/G34395.1. et al. (2006), Zhou et al. (2006a, 2006b, Qiu et al. (2011), L.M. Li et al. (2013), Cawood, P.A., Zhao, G.C., Yao, J.L., Wang, W., Xu, Y.J., and Wang, Y.J., 2017, Reconstructing Chen et al. (2014), Zhao (2015), Zhu et al. (2016), Y.J. Wang et al. (2016b), Yang South China in Phanerozoic and Precambrian supercontinents: Earth-Science Reviews, et al. (2016), Chen et al. (2017), Cawood et al. (2017), and references therein. v. 186, p. 173–194, https://doi.org/10.1016/j.earscirev.2017.06.001. Cawthorn, R.G., and Brown, P.A., 1976, A model for the formation and crystallization of co- rundum-normative calc-alkaline magmas through amphibole fractionation: The Journal of Geology, v. 84, p. 467–476, https://doi.org/10.1086/628212. Chappell, B.W., White, A.J.R., Williams, I.S., and Wyborn, D., 2004, Low- and high-temperature than a continental rift triggered by a mantle plume. Thus, it does not granites: Earth and Environmental Science Transactions of The Royal Society of Edinburgh, seem plausible for the South China block to have been located between v. 95, p. 125–140, https://doi.org/10.1017/S0263593300000973. Chen, Q., Sun, M., Long, X.P., and Yuan, C., 2015, Petrogenesis of Neoproterozoic adakitic Laurentia and Australia during the Neoproterozoic. Based on these find- tonalites and high-K granites in the eastern Songpan-Ganze fold belt and implications ings, we conclude that the South China block was located on the margin for the tectonic evolution of the western Yangtze block: Precambrian Research, v. 270, of the Rodinia supercontinent, adjoining India. p. 181–203, https://doi.org/10.1016/j.precamres.2015.09.004. Chen, W.T., Sun, W.-H., Wang, W., Zhao, J.-H., and Zhou, M.-F., 2014, “Grenvillian” intraplate mafic magmatism in the southwestern Yangtze block, SW China: Precambrian Research, CONCLUSIONS v. 242, p. 138–153, https://doi.org/10.1016/j.precamres.2013.12.019. Chen, X.Y., Liu, J.L., Fan, W.K., Qi, Y.C., Wang, W., Chen, J.F., and Burg, J.-P., 2017, Neoproterozoic granitoids along the Ailao Shan–Red River belt: Zircon U-Pb geochronology, Hf isotope (1) The Kuchahe, Leidashu, and Qizanmi intrusions from the western analysis and tectonic implications: Precambrian Research, v. 299, p. 244–263, https://doi Yangtze block were emplaced in the mid-Neoproterozoic (ca. 750 Ma). .org/10.1016/j.precamres.2017.06.024. (2) The Kuchahe intrusion is strongly peraluminous leucogranite and Clemens, J.D., and Wall, V.J., 1981, Crystallization and origin of some peraluminous S-type granitic magmas: Canadian Mineralogist, v. 19, p. 111–131. was likely produced by biotite-dehydration melting of a metapelitic source Collins, W.J., Beams, S.D., White, A.J.R., and Chappell, B.W., 1982, Nature and origin of A-type at relatively high temperature. The Leidashu A-type intrusion was derived granites with particular reference to southeastern Australia: Contributions to Mineralogy by partial melting of earlier Neoproterozoic granodiorites in the middle and Petrology, v. 80, p. 189–200, https://doi.org/10.1007/BF00374895. Creaser, R.A., Price, R.C., and Wormald, R.J., 1991, A-type granites revisited: Assessment of crust (~15 km), with mixing of basaltic magmas. The Qizanmi intru- a residual-source model: Geology, v. 19, p. 163–166, https://doi.org/10.1130/0091-7613 sion is hornblende gabbro and was likely derived by partial melting of a (1991)019<0163:ATGRAO>2.3.CO;2. shallow enriched lithospheric mantle source that had been modified by Dong, Y.P., Liu, X.M., Santosh, M., Chen, Q., Zhang, X.N., Li, W., He, D.F., and Zhang, G.W., 2012, Neoproterozoic accretionary tectonics along the northwestern margin of the Yangtze slab-released fluids, with accumulation of plagioclase and fractionation block, China: Constraints from zircon U-Pb geochronology and geochemistry: Precam- of mafic minerals. brian Research, v. 196–197, p. 247–274, https://doi.org/10.1016/j.precamres.2011.12.007.

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Eby, G.N., 1990, The A-type granitoids: A review of their occurrence and chemical character- in western Yangtze block: Lithos, v. 296–299, p. 547–562, https://doi.org/10.1016/j.lithos istics and speculations on their petrogenesis: Lithos, v. 26, p. 115–134, https://doi.org/10 .2017.11.034. .1016/0024-4937(90)90043-Z. Li, L.M., Lin, S., Xing, G., Davis, D.W., Davis, W.J., Xiao, W., and Yin, C., 2013, Geochemistry Eby, G.N., 1992, Chemical subdivision of the A-type granitoids: Petrogenetic and tectonic im- and tectonic implications of late Mesoproterozoic alkaline bimodal volcanic rocks from plications: Geology, v. 20, p. 641–644, https://doi.org/10.1130/0091-7613(1992)020<0641: the Tieshajie Group in the southeastern Yangtze block, South China: Precambrian Research, CSOTAT>2.3.CO;2. v. 230, p. 179–192, https://doi.org/10.1016/j.precamres.2013.02.004. Ernst, R.E., Buchan, K.L., 2002, Maximum size and distribution in time and space of mantle Li, X.H., Zhou, G.Q., Zhao, J.X., Fanning, C.M., and Compston, W., 1994, SHRIMP ion micro- plumes: Evidence from large igneous provinces: Journal of Geodynamics, v. 34, no. 2, p. probe zircon U-Pb age and Sm-Nd isotopic characteristics of the NE Jiangxi ophiolite 309–342 (see also Erratum, Journal of Geodynamics, v. 34, p. 711–714). and its tectonic implications: Chinese Journal of Geochemistry, v. 13, p. 317–325, https:// Ernst, R.E., and Buchan, K.L., 2003, Recognizing mantle plumes in the geological record: An- doi.org/10.1007/BF02838521. nual Review of Earth and Planetary Sciences, v. 31, p. 469–523, https://doi.org/10.1146 Li, X.H., Li, Z.X., Zhou, H.W., Liu, Y., and Kinny, P.D., 2002a, U-Pb zircon geochronology, geo- /annurev.earth.31.100901.145500. chemistry and Nd isotopic study of Neoproterozoic bimodal volcanic rocks in the Kangdian Finger, F., and Schiller, D., 2012, Lead contents of S-type granites and their petrogenetic sig- Rift of South China: Implications for the initial rifting of Rodinia: Precambrian Research, nificance: Contributions to Mineralogy and Petrology, v. 164, p. 747–755, https://doi.org v. 113, p. 135–154, https://doi.org/10.1016/S0301-9268(01)00207-8. /10.1007/s00410-012-0771-3. Li, X.H., Li, Z.-X., Ge, W., Zhou, H., Li, W., Liu, Y., and Wingate, M.T.D., 2003a, Neoprotero- Gan, B.P., Lai, S.C., and Qin, J.F., 2016, Petrogenesis and implications for the Neoproterozoic zoic granitoids in South China: Crustal melting above a mantle plume at ca. 825 Ma?: monzogranite in Pinghe, Micang Mountain: Geological Review (Dizhi Lunping), v. 62, Precambrian Research, v. 122, p. 45–83, https://doi.org/10.1016/S0301-9268(02)00207-3. p. 929–944 [in Chinese with English abstract]. Li, X.H., Qi, C.S., Liu, Y., Liang, X.R., Tu, X.L., Xie, L.W., and Yang, Y.H., 2005, Petrogenesis Gan, B.P., Lai, S.C., Qin, J.F., Zhu, R.Z., Zhao, S.W., and Li, T., 2017, Neoproterozoic alkaline intru- of the Neoproterozoic bimodal volcanic rocks along the western margin of the Yangtze sive complex in the northwestern Yangtze block, Micang Mountains region, South China: block: New constraints from Hf isotopes and Fe/Mn ratios: Chinese Science Bulletin, v. 50, Petrogenesis and tectonic significance: International Geology Review, v. 59, p. 311–332, p. 2481–2486, https://doi.org/10.1360/982005-287. https://doi.org/10.1080/00206814.2016.1258676. Li, X.H., Li, W.-X., Li, Z.-X., Lo, C.-H., Wang, J., Ye, M.-F., and Yang, Y.-H., 2009, Amalgamation Greentree, M.R., Li, Z.-X., Li, X.-H., and Wu, H., 2006, Late Mesoproterozoic to earliest Neo- between the Yangtze and Cathaysia blocks in South China: Constraints from SHRIMP proterozoic basin record of the Sibao orogenesis in western South China and relation- U-Pb zircon ages, geochemistry and Nd-Hf isotopes of the Shuangxiwu volcanic rocks: ship to the assembly of Rodinia: Precambrian Research, v. 151, p. 79–100, https://doi.org Precambrian Research, v. 174, p. 117–128, https://doi .org /10 .1016 /j .precamres .2009 .07 .004 . /10.1016/j.precamres.2006.08.002. Li, Z.X., Zhang, L., and Powell, C.W.A., 1995, South China in Rodinia: Part of the missing link Guo, J.L., Gao, S., Wu, Y.B., Li, M., Chen, K., Hu, Z.C., Liang, Z.W., Liu, Y.S., Zhou, L., Zong, between Australia–East Antarctica and Laurentia?: Geology, v. 23, p. 407–410, https://doi K.Q., Zhang, W., and Chen, H.H., 2014, 3.45 Ga granitic gneisses from the Yangtze craton, .org/10.1130/0091-7613(1995)023<0407:SCIRPO>2.3.CO;2. South China: Implications for Early Archean crustal growth: Precambrian Research, v. 242, Li, Z.X., Li, X.H., Zhou, H., and Kinny, P.D., 2002b, Grenvillian continental collision in South China: p. 82–95, https://doi.org/10.1016/j.precamres.2013.12.018. New SHRIMP U-Pb zircon results and implications for the configuration of Rodinia: Geol- Hu, P.Y., Zhai, Q.G., Wang, J., Tang, Y., and Ren, G.M., 2017, The Shimian ophiolite in the west- ogy, v. 30, p. 163–166, https://doi .org /10 .1130 /0091 -7613 (2002)030 <0163: GCCISC>2 .0 .CO;2 . ern Yangtze block, SW China: Zircon SHRIMP U-Pb ages, geochemical and Hf-O isotopic Li, Z.X., Li, X.H., Kinny, P.D., Wang, J., Zhang, S., and Zhou, H., 2003b, Geochronology of Neo- characteristics, and tectonic implications: Precambrian Research, v. 298, p. 107–122, https:// proterozoic syn-rift magmatism in the Yangtze craton, South China, and correlations with doi.org/10.1016/j.precamres.2017.06.005. other continents: Evidence for a mantle superplume that broke up Rodinia: Precambrian Huang, X.L., Xu, Y.G., Li, X.H., Li, W.X., Lan, J.B., Zhang, H.H., Liu, Y.S., Wang, Y.B., Li, H.Y., Research, v. 122, p. 85–109, https://doi.org/10.1016/S0301-9268(02)00208-5. Luo, Z.Y., and Yang, Q.J., 2008, Petrogenesis and tectonic implications of Neoproterozoic, Li, Z.-X., Wartho, J.-A., Occhipinti, S., Zhang, C.-L., Li, X.-H., Wang, J., and Bao, C., 2007, Early highly fractionated A-type granites from Mianning, South China: Precambrian Research, history of the eastern Sibao orogen (South China) during the assembly of Rodinia: New v. 165, p. 190–204, https://doi.org/10.1016/j.precamres.2008.06.010. mica 40Ar/39Ar dating and SHRIMP U-Pb detrital zircon provenance constraints: Precam- Inger, S., and Harris, N., 1993, Geochemical constraints on leucogranite magmatism in the brian Research, v. 159, p. 79–94, https://doi.org/10.1016/j.precamres.2007.05.003. Langtang Valley, Nepal Himalaya: Journal of Petrology, v. 34, p. 345–368, https://doi.org Li, Z.X., Bogdanova, S.V., Collins, A.S., Davidson, A., De Waele, B., Ernst, R.E., Fitzsimons, /10.1093/petrology/34.2.345. I.C.W., Fuck, R.A., Gladkochub, D.P., Jacobs, J., Karlstrom, K.E., Lu, S., Natapov, L.M., Jahn, B.M., Wu, F.Y., and Chen, B., 2000, Granitoids of the Central Asian orogenic belt and con- Pease, V., Pisarevsky, S.A., Thrane, K., and Vernikovsky, V., 2008, Assembly, configuration, tinental growth in the Phanerozoic: Transactions of the Royal Society of Edinburgh–Earth and break-up history of Rodinia: A synthesis: Precambrian Research, v. 160, p. 179–210, Sciences, v. 91, p. 181–193, https://doi.org/10.1017/S0263593300007367. https://doi.org/10.1016/j.precamres.2007.04.021. Jiang, G.Q., Sohl, L.E., and Christie-Blick, N., 2003, Neoproterozoic stratigraphic comparison Ling, W.L., Gao, S., Zhang, B.R., Li, H.M., Liu, Y., and Cheng, J.P., 2003, Neoproterozoic tectonic of the Lesser Himalaya (India) and Yangtze block (South China): Paleogeographic impli- evolution of the northwestern Yangtze craton, South China: Implications for amalgama- cations: Geology, v. 31, p. 917–920, https://doi.org/10.1130/G19790.1. tion and break-up of the Rodinia supercontinent: Precambrian Research, v. 122, p. 111–140, Jiang, Y.H., and Zhu, S.Q., 2017, Petrogenesis of the Late Jurassic peraluminous biotite gran- https://doi.org/10.1016/S0301-9268(02)00222-X. ites and muscovite-bearing granites in SE China: Geochronological, elemental and Sr- Ling, W.L., Gao, S., Cheng, J.P., Jiang, J.S., Yuan, H.L., and Hu, Z.C., 2006, Neoproterozoic Nd-O-Hf isotopic constraints: Contributions to Mineralogy and Petrology, v. 172, p. 101, magmatic events within the Yangtze continental interior and along its northern margin and https://doi.org/10.1007/s00410-017-1422-5. their tectonic implication: constraint from the ELA-ICP-MS U-Pb geochronology of zircons Jiang, Y.H., Jin, G.D., Liao, S.Y., Zhou, Q., and Zhao, P., 2010, Geochemical and Sr-Nd-Hf isoto- from the Huangling and Hannan complexes: Acta Petrologica Sinica, v. 22, p. 387–396. pic constraints on the origin of Late Triassic granitoids from the Qinling orogen, central Liu, Z., Zhou, Q., Lai, Y., Qing, C.S., Li, Y.X., Wu, J.Y., and Xia, X.B., 2015, Petrogenesis of the China: Implications for a continental arc to continent-continent collision: Lithos, v. 117, Early Cretaceous Laguila bimodal intrusive rocks from the Tethyan Himalaya: Implica- p. 183–197, https://doi.org/10.1016/j.lithos.2010.02.014. tions for the break-up of Eastern Gondwana: Lithos, v. 236–237, p. 190–202, https://doi Jiang, Y.H., Zhao, P., Zhou, Q., Liao, S.Y., and Jin, G.D., 2011, Petrogenesis and tectonic impli- .org/10.1016/j.lithos.2015.09.006. cations of Early Cretaceous S- and A-type granites in the northwest of the Gan-Hang rift, McDonough, W.F., and Sun, S.S., 1995, The composition of the Earth: Chemical Geology, v. 120, SE China: Lithos, v. 121, p. 55–73, https://doi.org/10.1016/j.lithos.2010.10.001. p. 223–253, https://doi.org/10.1016/0009-2541(94)00140-4. Jiang, Y.H., Jia, R.Y., Liu, Z., Liao, S.Y., Zhao, P., and Zhou, Q., 2013, Origin of Middle Trias- McKenzie, D.A.N., and O’Nions, R.K., 1991, Partial melt distributions from inversion of rare sic high-K calc-alkaline granitoids and their potassic microgranular enclaves from the earth element concentrations: Journal of Petrology, v. 32, p. 1021–1091, https://doi.org western Kunlun orogen, northwest China: A record of the closure of Paleo-Tethys: Lithos, /10.1093/petrology/32.5.1021. v. 156–159, p. 13–30, https://doi.org/10.1016/j.lithos.2012.10.004. Meng, E., Liu, F.L., Du, L.L., Liu, P.H., and Liu, J.H., 2015, Petrogenesis and tectonic significance Jourdan, F., Bertrand, H., Schärer, U., Blichert-Toft, J., Féraud, G., and Kampunzu, A.B., 2007, of the Baoxing granitic and mafic intrusions, southwestern China: Evidence from zircon Major and trace element and Sr, Nd, Hf, and Pb isotope compositions of the Karoo large U-Pb dating and Lu-Hf isotopes, and whole-rock geochemistry: Gondwana Research, v. 28, igneous province, Botswana-Zimbabwe: Lithosphere vs mantle plume contribution: Jour- p. 800–815, https://doi.org/10.1016/j.gr.2014.07.003. nal of Petrology, v. 48, p. 1043–1077, https://doi.org/10.1093/petrology/egm010. Miller, C., Schuster, R., Klötzli, U., Frank, W., and Purtscheller, F., 1999, Post-collisional potassic Kepezhinskas, P., McDernott, F., Defant, M., Hochstaedter, A., Drummond, M.S., Hawkesworth, and ultrapotassic magmatism in SW Tibet: Geochemical and Sr-Nd-Pb-O isotopic con- C.J., Koloskov, A., Maury, R.C., and Bellon, H., 1997, Trace element and Sr-Nd-Pb isotopic straints for mantle source characteristics and petrogenesis: Journal of Petrology, v. 40, constraints on a three-component model of Kamchatka arc petrogenesis: Geochimica p. 1399–1424, https://doi.org/10.1093/petroj/40.9.1399. et Cosmochimica Acta, v. 61, p. 577–600, https://doi.org/10.1016/S0016-7037(96)00349-3. Patiño Douce, A.E., 1997, Generation of metaluminous A-type granites by low-pressure melt- Knesel, K.M., and Davidson, J.P., 2002, Insights into collisional magmatism from isotopic ing of calc-alkaline granitoids: Geology v. 25, p. 743–746, https://doi .org /10 .1130 /0091 -7613 fingerprints of melting reactions: Science, v. 296, p. 2206–2208, https://doi .org /10 .1126 (1997)025<0743:GOMATG>2.3.CO;2. /science.1070622. Patiño Douce, A.E., and Beard, J.S., 1995, Dehydration-melting of biotite gneiss and quartz Lai, S.C., Qin, J.F., Zhu, R.Z., and Zhao, S.W., 2015, Neoproterozoic quartz monzodiorite-grano- amphibolite from 3 to 15 kbar: Journal of Petrology, v. 36, p. 707–738, https://doi.org/10 diorite association from the Luding-Kangding area: Implications for the interpretation of .1093/petrology/36.3.707. an active continental margin along the Yangtze block (South China block): Precambrian Patiño Douce, A.E., and Harris, N., 1998, Experimental constraints on Himalayan anatexis: Research, v. 267, p. 196–208, https://doi.org/10.1016/j.precamres.2015.06.016. Journal of Petrology, v. 39, p. 689–710, https://doi.org/10.1093/petroj/39.4.689. Le Maitre, R.W., ed., 2002, Igneous Rocks: A Classification and Glossary of Terms (2nd ed.): Cam- Patiño Douce, A.E., and Johnston, A.D., 1991, Phase equilibria and melt productivity in the bridge, UK, Cambridge University Press, 236 p., https://doi .org /10 .1017 /CBO9780511535581 . pelitic system: Implications for the origin of peraluminous granitoids and aluminous Li, J.Y., Wang, X.L., and Gu, Z.D., 2018, Petrogenesis of the Jiaoziding granitoids and associ- granulites: Contributions to Mineralogy and Petrology, v. 107, p. 202–218, https://doi .org ated basaltic porphyries: Implications for extensive early Neoproterozoic arc magmatism /10.1007/BF00310707.

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Poitrasson, F., Duthou, J.-L., and Pin, C., 1995, The relationship between petrology and Nd iso- from granitoids and metasedimentary rocks of the Jiangnan orogen, China: Precambrian topes as evidence for contrasting anorogenic granite genesis: Example of the Corsican Prov- Research, v. 242, p. 154–171, https://doi.org/10.1016/j.precamres.2013.12.023. ince: Journal of Petrology, v. 36, p. 1251–1274, https://doi .org /10 .1093 /petrology /36 .5 .1251 . Wang, Y.J., Zhou, Y.Z., Cai, Y.F., Liu, H.C., Zhang, Y.Z., and Fan, W.M., 2016b, Geochronological Powell, C.M., and Pisarevsky, S.A., 2002, Late Neoproterozoic assembly of East Gondwana: and geochemical constraints on the petrogenesis of the Ailaoshan granitic and migma- Geology, v. 30, p. 3–6, https://doi .org /10 .1130 /0091 -7613 (2002)030 <0003: LNAOEG>2 .0 .CO;2 . tite rocks and its implications on Neoproterozoic subduction along the SW Yangtze block: Qi, X.X., Santosh, M., Zhu, L.H., Zhao, Y.H., Hu, Z.C., Zhang, C., and Ji, F.B., 2014, Mid-Neopro- Precambrian Research, v. 283, p. 106–124, https://doi .org /10 .1016 /j .precamres .2016 .07 .017 . terozoic arc magmatism in the northeastern margin of the Indochina block, SW China: Watson, E.B., and Harrison, T.M., 1983, Zircon saturation revisited: Temperature and compo- Geochronological and petrogenetic constraints and implications for Gondwana assembly: sition effects in a variety of crustal magma types: Earth and Planetary Science Letters, Precambrian Research, v. 245, p. 207–224, https://doi .org /10 .1016 /j .precamres .2014 .02 .008 . v. 64, p. 295–304, https://doi.org/10.1016/0012-821X(83)90211-X. Qiu, X.F., Ling, W.L., Liu, X.M., Kusky, T., Berkana, W., Zhang, Y.H., Gao, Y.J., Lu, S.S., Kuang, H., Williams, I.S., Buick, A., and Cartwright, I., 1996, An extended episode of early Mesoproterozoic and Liu, C.X., 2011, Recognition of Grenvillian volcanic suite in the Shennongjia region metamorphic fluid flow in the Reynold region, central Australia: Journal of Metamorphic and its tectonic significance for the South China craton: Precambrian Research, v. 191, Geology, v. 14, p. 29–47, https://doi.org/10.1111/j.1525-1314.1996.00029.x. p. 101–119, https://doi.org/10.1016/j.precamres.2011.09.011. Xu, Y., Yang, K.G., Polat, A., and Yang, Z.N., 2016, The ~860 Ma mafic dikes and granitoids from Robinson, J.A.C., and Wood, B.J., 1998, The depth of the spinel to garnet transition at the the northern margin of the Yangtze block, China: A record of oceanic subduction in the peridotite solidus: Earth and Planetary Science Letters, v. 164, p. 277–284, https://doi .org early Neoproterozoic: Precambrian Research, v. 275, p. 310–331, https://doi.org/10.1016 /10.1016/S0012-821X(98)00213-1. /j.precamres.2016.01.021. Shellnutt, J.G., and Zhou, M.F., 2007, Permian peralkaline, peraluminous and metaluminous Yang, Y.N., Wang, X.C., Li, Q.L., and Li, X.H., 2016, Integrated in situ U-Pb age and Hf-O analyses A-type granites in the Panxi district, SW China: Their relationship to the Emeishan mantle of zircon from Suixian Group in northern Yangtze: New insights into the Neoproterozoic plume: Chemical Geology, v. 243, p. 286–316, https://doi .org /10 .1016 /j .chemgeo .2007 .05 .022 . low-δ18O magmas in the South China block: Precambrian Research, v. 273, p. 151–164, Skjerlie, K.P., and Johnston, A.D., 1996, Vapour-absent melting from 10 to 20 kbar of crustal https://doi.org/10.1016/j.precamres.2015.12.008. rocks that contain multiple hydrous phases: Implications for anatexis in the deep to Yang, Z.Y., Sun, Z.M., Yang, T.S., and Pei, Y.L., 2004, A long connection (750–380 Ma) between very deep continental crust and active continental margins: Journal of Petrology, v. 37, South China and Australia: Paleomagnetic constraints: Earth and Planetary Science Let- p. 661–691, https://doi.org/10.1093/petrology/37.3.661. ters, v. 220, p. 423–434, https://doi.org/10.1016/S0012-821X(04)00053-6. Steiner, M., Li, G.X., Qian, Y., Zhu, M.Y., and Erdtmann, B.D., 2007, Neoproterozoic to early Zhang, S.B., Wu, R.X., and Zheng, Y.F., 2012, Neoproterozoic continental accretion in South Cambrian small shelly fossil assemblages and a revised biostratigraphic correlation of China: Geochemical evidence from the Fuchuan ophiolite in the Jiangnan orogen: Pre- the Yangtze Platform (China): Palaeogeography, Palaeoclimatology, Palaeoecology, v. 254, cambrian Research, v. 220–221, p. 45–64, https://doi.org/10.1016/j.precamres.2012.07.010. p. 67–99, https://doi.org/10.1016/j.palaeo.2007.03.046. Sun, S.S., and McDonough, W.F., 1989, Chemical and isotopic systematics of oceanic basalts: Zhao, G., 2015, Jiangnan orogen in South China: Developing from divergent double sub- Implications for mantle composition and processes, in Saunders, A.D., and Norry, M.J., duction: Gondwana Research, v. 27, p. 1173–1180, https://doi.org/10.1016/j.gr.2014.09.004. eds., Magmatism in the Ocean Basins: Geological Society [London] Special Publication Zhao, G., and Cawood, P.A., 2012, Precambrian geology of China: Precambrian Research, 42, p. 313–345, https://doi.org/10.1144/GSL.SP.1989.042.01.19. v. 222–223, p. 13–54, https://doi.org/10.1016/j.precamres.2012.09.017. Sylvester, P.J., 1998, Post-collisional strongly peraluminous granites: Lithos, v. 45, p. 29–44, Zhao, J.H., and Zhou, M.F., 2007, Geochemistry of Neoproterozoic mafic intrusions in the https://doi.org/10.1016/S0024-4937(98)00024-3. Panzhihua district (Sichuan Province, SW China): Implications for subduction-related Tapponnier, P., Lacassin, R., Leloup, P.H., Schärer, U., Zhong, D.L., Liu, X.H., Ji, S.C., Zhang, L.S., metasomatism in the upper mantle: Precambrian Research, v. 152, p. 27–47, https://doi and Zhong, J.Y., 1990, The Ailao Shan/Red River metamorphic belt: Tertiary left lateral shear be- .org/10.1016/j.precamres.2006.09.002. tween Indochina and South China: Nature, v. 343, p. 431–437, https://doi.org/10.1038/343431a0. Zhao, J.H., and Zhou, M.F., 2008, Neoproterozoic adakitic plutons in the northern margin of the Taylor, S.R., and McLennan, S.M., 1995, The geochemical evolution of the continental crust: Yangtze block, China: Partial melting of a thickened lower crust and implications for secu- Reviews of Geophysics, v. 33, p. 241–265, https://doi.org/10.1029/95RG00262. lar crustal evolution: Lithos, v. 104, p. 231–248, https://doi .org /10 .1016 /j .lithos .2007 .12 .009 . Thirlwall, M.F., Smith, T.E., Graham, A.M., Theodorou, N., Hollings, P., Davidson, J.P., and Zhao, J.H., Zhou, M.F., Yan, D.P., Yang, Y.H., and Sun, M., 2008a, Zircon Lu-Hf isotopic con- Arculus, R.J., 1994, High field strength element anomalies in arc lavas: Source or pro- straints on Neoproterozoic subduction-related crustal growth along the western margin cess?: Journal of Petrology, v. 35, p. 819–838, https://doi.org/10.1093/petrology/35.3.819. of the Yangtze block, South China: Precambrian Research, v. 163, p. 189–209, https://doi Tucker, R.D., Ashwal, L.D., and Torsvik, T.H., 2001, U-Pb geochronology of Seychelles granitoids: .org/10.1016/j.precamres.2007.11.003. A Neoproterozoic continental arc fragment: Earth and Planetary Science Letters, v. 187, Zhao, X.F., Zhou, M.F., Li, J.W., and Wu, F.Y., 2008b, Association of Neoproterozoic A- and p. 27–38, https://doi.org/10.1016/S0012-821X(01)00282-5. I-type granites in South China: Implications for generation of A-type granites in a sub- Tucker, R.D., Roig, J.Y., Moine, B., Delor, C., and Peters, S.G., 2014, A geological synthesis of duction-related environment: Chemical Geology, v. 257, p. 1–15, https://doi.org/10.1016 the Precambrian shield in Madagascar: Journal of African Earth Sciences, v. 94, p. 9–30, /j.chemgeo.2008.07.018. https://doi.org/10.1016/j.jafrearsci.2014.02.001. Zheng, Y.F., Wu, R.X., Wu, Y.B., Zhang, S.B., Yuan, H.L., and Wu, F.Y., 2008, Rift melting of juve- Turner, S.P., Foden, J.D., and Morrison, R.S., 1992, Derivation of some A-type magmas by nile arc-derived crust: Geochemical evidence from Neoproterozoic volcanic and granitic fractionation of basaltic magma: An example from the Padthaway Ridge, South Australia: rocks in the Jiangnan orogen, South China: Precambrian Research, v. 163, p. 351–383, Lithos, v. 28, p. 151–179, https://doi.org/10.1016/0024-4937(92)90029-X. https://doi.org/10.1016/j.precamres.2008.01.004. Vervoort, J.D., Patchett, P.J., Blichert-Toft, J., and Albarède, F., 1999, Relationships between Zhou, J.L., Li, X.H., Tang, G.Q., Gao, B.Y., Bao, Z.A., Ling, X.X., Wu, L.G., Zhu, Y.S., and Liao, X., Lu-Hf and Sm-Nd isotopic systems in the global sedimentary system: Earth and Plan- 2018, Ca. 890 Ma magmatism in the northwest Yangtze block, South China: SIMS U-Pb etary Science Letters, v. 168, p. 79–99, https://doi.org/10.1016/S0012-821X(99)00047-3. dating, in-situ Hf-O isotopes, and tectonic implications: Journal of Asian Earth Sciences, Vielzeuf, D., and Holloway, J.R., 1988, Experimental determination of the fluid-absent melting v. 151, p. 101–111, https://doi.org/10.1016/j.jseaes.2017.10.029. relations in the pelitic system: Contributions to Mineralogy and Petrology, v. 98, p. 257–276, Zhou, M.F., Yan, D.-P., Kennedy, A.K., Li, Y., and Ding, J., 2002, SHRIMP U-Pb zircon geochro- https://doi.org/10.1007/BF00375178. nological and geochemical evidence for Neoproterozoic arc-magmatism along the west- Wang, F., Liu, F.L., and Liu, P.H., 2013a, Metamorphic evolution of meta-sedimentary rocks ern margin of the Yangtze block, South China: Earth and Planetary Science Letters, v. 196, within the Diancang Shan–Ailao Shan metamorphic complex belt: Acta Petrologica Si- p. 51–67, https://doi.org/10.1016/S0012-821X(01)00595-7. nica v. 29, p. 630–640 [in Chinese with English abstract]. Zhou, M.F., Yan, D.P., Wang, C., Qi, L., and Kennedy, A., 2006a, Subduction-related origin of Wang, W., and Zhou, M.F., 2012, Sedimentary record of the Yangtze block (South China) and the 750 Ma Xuelongbao adakitic complex (Sichuan Province, China): Implications for the their correlation with equivalent Neoproterozoic sequences on adjacent continents: Sedi- tectonic setting of the giant Neoproterozoic magmatic event in South China: Earth and mentary Geology, v. 265–266, p. 126–142. Planetary Science Letters, v. 248, p. 286–300, https://doi.org/10.1016/j.epsl.2006.05.032. Wang, W., Zhou, M.F., Yan, D.P., Li, L., and Malpas, J., 2013b, Detrital zircon record of Neo- Zhou, M.F., Ma, Y.X., Yan, D.P., Xia, X.P., Zhao, J.H., and Sun, M., 2006b, The Yanbian terrane proterozoic active-margin sedimentation in the eastern Jiangnan orogen, South China: (southern Sichuan Province, SW China): A Neoproterozoic arc assemblage in the west- Precambrian Research, v. 235, p. 1–19. ern margin of the Yangtze block: Precambrian Research, v. 144, p. 19–38, https://doi .org Wang, W., Cawood, P.A., Zhou, M.F., and Zhao, J.H., 2016a, Paleoproterozoic magmatic and /10.1016/j.precamres.2005.11.002. metamorphic events link Yangtze to northwest Laurentia in the Nuna supercontinent: Earth Zhu, W.G., Zhong, H., and Deng, H.L., 2006, SHRIMP zircon U-Pb age, geochemistry, and Nd- and Planetary Science Letters, v. 433, p. 269–279, https://doi .org /10 .1016 /j .epsl .2015 .11 .005 . Sr isotopes of the Gaojiacun mafic-ultramafic intrusive complex, southwest China: In- Wang, X.L., Zhou, J.C., Qiu, J.S., Zhang, W.L., Liu, X.M., and Zhang, G.L., 2006, LA-ICP-MS ternational Geology Review, v. 48, p. 650–668, https://doi.org/10.2747/0020-6814.48.7.650. U-Pb zircon geochronology of the Neoproterozoic igneous rocks from Northern Guangxi, South China: Implications for petrogenesis and tectonic evolution: Precambrian Research, Zhu, W.G., Zhong, H., Li, X.H., Deng, H.L., He, D.F., Wu, K.W., and Bai, Z.J., 2008, SHRIMP zir- v. 145, p. 111–130, https://doi.org/10.1016/j.precamres.2005.11.014. con U-Pb geochronology, elemental, and Nd isotopic geochemistry of the Neoprotero- Wang, X.L., Zhao, G.C., Zhou, J.C., Liu, Y.S., and Hu, J., 2008, Geochronology and Hf isotopes zoic mafic dykes in the Yanbian area, SW China: Precambrian Research, v. 164, p. 66–85, of zircon from volcanic rocks of the Shuangqiaoshan Group, South China: Implications https://doi.org/10.1016/j.precamres.2008.03.006. for the Neoproterozoic tectonic evolution of the eastern Jiangnan orogen: Gondwana Zhu, W.G., Zhong, H., Li, Z.X., Bai, Z.J., and Yang, Y.J., 2016, SIMS zircon U-Pb ages, geochem- Research, v. 14, p. 355–367, https://doi.org/10.1016/j.gr.2008.03.001. istry and Nd-Hf isotopes of ca. 1.0 Ga mafic dykes and volcanic rocks in the Huili area, SW Wang, X.L., Zhou, J.C., Wan, Y.S., Kitajima, K., Wang, D., Bonamici, C., Qiu, J.S., and Sun, T., China: Origin and tectonic significance: Precambrian Research, v. 273, p. 67–89, https:// 2013c, Magmatic evolution and crustal recycling for Neoproterozoic strongly peralumi- doi.org/10.1016/j.precamres.2015.12.011. nous granitoids from southern China: Hf and O isotopes in zircon: Earth and Planetary Science Letters, v. 366, p. 71–82, https://doi.org/10.1016/j.epsl.2013.02.011. MANUSCRIPT RECEIVED 3 AUGUST 2018 Wang, X.L., Zhou, J.C., Griffin, W.L., Zhao, G.C., Yu, J.H., Qiu, J.S., Zhang, Y.J., and Xing, G.F., REVISED MANUSCRIPT RECEIVED 2 DECEMBER 2018 2014, Geochemical zonation across a Neoproterozoic orogenic belt: Isotopic evidence MANUSCRIPT ACCEPTED 22 FEBRUARY 2019

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