Ore genesis of the Late Cretaceous Larong porphyry W-Mo deposit, eastern Tibet: Evidence from in-situ trace elemental and S-Pb isotopic compositions

Journal Pre-proofs Ore genesis of the Late Cretaceous Larong porphyry W-Mo deposit, eastern Tibet: Evidence from in-situ trace elemental and S-Pb isotopic compositions Jun Liu, Wenchang Li, Xiangping Zhu, Jia-Xi Zhou, Haijun Yu PII: DOI: Reference:

S1367-9120(19)30551-6 https://doi.org/10.1016/j.jseaes.2019.104199 JAES 104199

To appear in:

Journal of Asian Earth Sciences

Received Date: Revised Date: Accepted Date:

3 April 2019 14 December 2019 15 December 2019

Please cite this article as: Liu, J., Li, W., Zhu, X., Zhou, J-X., Yu, H., Ore genesis of the Late Cretaceous Larong porphyry W-Mo deposit, eastern Tibet: Evidence from in-situ trace elemental and S-Pb isotopic compositions, Journal of Asian Earth Sciences (2019), doi: https://doi.org/10.1016/j.jseaes.2019.104199

This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

© 2019 Published by Elsevier Ltd.

Ore genesis of the Late Cretaceous Larong porphyry W-Mo deposit, eastern Tibet: Evidence from in-situ trace elemental and S-Pb isotopic compositions

Jun Liua, Wenchang Lia, b,*, Xiangping Zhub, Jia-Xi Zhouc, Haijun Yud

a) Faculty of Earth Resources, China University of Geosciences, Wuhan 430074, China; b) Chengdu Center of China Geological Survey, Chengdu 610081, China; c) School of Resource Environment and Earth Sciences, Yunnan University, Kunming 650500, China; d) Yunnan Geological Survey, Kunming 650051, China;

*Corresponding author, Email address: [email protected] (W. Li)

Abstract The Late Cretaceous (ca. 92 Ma) Larong porphyry W-Mo deposit (39.44 Mt WO3 @ 0.1541%), a newly discovered deposit in the easternmost Bangong-Nujiang metallogenic belt (BNMB), is located in eastern Tibet. The W-Mo mineralization occurs as veins and stock-works hosted in monzogranite porphyry, granodiorite porphyry and surrounding quartz schist, and can be divided into two main paragenetic stages: the W-mineralization stage (Stage I) consists of various K-feldspar-quartz-scheelite veins and the quartz-sulfide stage (Stage II) is dominated by molybdenite and pyrite, of which the latter can be further subdivided into three sub-stages. Here, we present LA-ICPMS in-situ trace elements and S-Pb isotopes of sulfides from the Larong deposit, in order to constrain the sources of ore-forming elements and the processes of mineralization. Our study shows that pyrite is rich in Co and As, molybdenite is rich in W, Pb and Bi, and chalcopyrite has high Sn contents. These results are consistent with the mineralization characteristics of the Larong deposit, where the main metallogenic elements are W and Mo, accompanied by Bi, Sn and Cu. Overall, sulfides from the Larong deposit have calculated δ34SVCDT values ranging from 0.25‰ to 6.37‰, suggesting a predominantly magmatic origin for sulfur. From Stage II-1, to Stage II-2, to Stage II-3, the average δ34SVCDT values of pyrite change from 0.33‰, to 1.88‰, to 5.34‰, showing a progressive and gradual change in redox and temperature conditions. Molybdenite has high Pb isotopic ratios (208Pb/204Pb = 39.356–39.908, 207Pb/204Pb

= 15.747–15.928, 206Pb/204Pb = 18.843–20.120) but low Re contents, and

pyrite has low Ni contents, implying that the ore-forming materials were mainly derived

from the crust. We propose that the W-Mo mineralization is genetically related to the Late Cretaceous monzogranite porphyry, with the mineralization of W and Mo occurring as a result of decreases in temperature and oxygen fugacity of the oreforming fluid exsolved from the magma. In combination with previous studies, our study led to the identification of three W-dominated polymetallic metallogenic events and mineralization potential of igneous rocks in the BNMB. Key words: Larong porphyry W-Mo deposit; in-situ S-Pb isotopes; in-situ trace elements; Bangong-Nujiang metallogenic belt

1. Introduction The Bangong-Nujiang suture zone is an east-west trending zone that separates the southern Qiangtang and northern Lhasa terranes, and mainly consists of JurassicCretaceous flysch and ophiolitic mélange (Yin and Harrison, 2000; Pan et al., 2012; Metcalfe, 2013). In the Bangong-Nujiang metallogenic belt (BNMB) (Fig. 1B), there are abundant porphyry-skarn Cu-Au deposits (Li et al., 2013a, 2016a; Zhu et al., 2015, 2017; Tang et al., 2017; Zhang et al., 2018), skarn Fe-Cu deposits (Zhao et al., 2011; Yu et al., 2015; Geng et al., 2016; Zhang et al., 2018), hydrothermal vein-type Au deposits (Li et al., 2005; Liu et al., 2014), porphyry-hydrothermal W-Sn deposits (Shentu and Wang et al., 1991; Yong, 2007; Luo et al., 2014), hydrothermal Pb-Zn deposits (Qu et al., 2009; Lu et al., 2012; Geng et al., 2016), and magmatic chromite deposits (Shi et al., 2012), which are closely related to the Mesozoic-Cenozoic evolution of the Bangong-Nujiang Tethys ocean (Cao et al., 2017; Li et al., 2017b, 2018a; Liu et al., 2018; Zhang et al., 2018). While numerous studies have been done on the mineralization style, regional metallogeny, petrogenesis and tectonic setting of these deposits, the sources of ore-forming materials remain poorly constrained (e.g. Zhao et al., 2011; Yu et al., 2013; Wang et al., 2017; Wu et al., 2018), which hinders further understanding of the metallogenesis and metallogenic regularity of the BNMB. Granodiorite porphyry (GP) and monzogranite porphyry (MP) intrusions and porphyry-related alteration and mineralization have been identified in the Larong ore deposit. Laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) zircon U-Pb dating has revealed that the GP and MP were emplaced at 213.8 ± 1.3

Ma and 93.9 ± 1.3 Ma, respectively (Liu et al., unpublished data), and the Re-Os weighted average age (91.8 Ma) of molybdenites from the Larong deposit (Liu et al., 2019) is consistent with the zircon U-Pb age of the MP. Hence, the Larong deposit was interpreted as a porphyry W-Mo deposit. This deposit is still under exploration and contains more than 39.44 Mt of WO3 at an average grade of 0.1541% (Liu et al., 2019). Although the general geology, mineralization style and metallogenic setting of this deposit have been reported by Luo et al. (2014) and Liu et al. (2019), the sources of ore-forming materials and the processes of W-Mo mineralization are still not constrained. In this paper, in-situ trace elemental and S-Pb isotopic compositions of sulfides from the Larong deposit are reported in order to constrain ore genesis. Combined with previously reported metallogenic ages and S-Pb isotopic data of the Cu-Au deposits, Fe-Cu polymetallic deposits and W-Sn-Mo deposits in the BNMB, this study allows us to discuss the regional metallogenesis and exploration vectors. 2. Regional geology The Tibetan Plateau comprises, from south to north, the Himalayan sequence, Lhasa terrane, Qiangtang terrane and Songpan-Ganze complex (Fig. 1A; Yin and Harrison, 2000). The Bangong-Nujiang suture zone is the main suture zone separating the Lhasa and Qiangtang terranes (Fig. 1B; Pan et al., 2012; Metcalfe, 2013). Mesozoic-Cenozoic magmatic activities (Zhu et al., 2009, 2013; Wang et al., 2016; Liu et al., 2017; Li et al., 2018a; He et al., 2019; Peng et al., 2019) and a great deal of CuAu deposits (Li et al., 2016a, 2017b, 2017c, 2018a; Zhu et al., 2017; Zhang et al.,

2018), Fe-Cu polymetallic deposits (Chen et al., 2014; Geng et al., 2016; Wu et al., 2018) and W-Sn-Mo-Cu deposits (Shentu and Wang, 1991; Yong, 2007; Luo et al., 2014) are extensively developed on both sides of the Bangong-Nujiang suture zone, and constitute the BNMB, an important metallogenic zone of non-ferrous and precious metal deposits in China. The Leiwuqi-Zogang metallogenic belt (LZMB), located in the southeastern part of the BNMB (Fig. 1B), is an important non-ferrous metal metallogenic belt in eastern Tibet. The Proterozoic Jitang and Youxi Groups which constitute the crystalline basement of eastern Tibet are distributed as a NW-trending belt in the middle part of the LZMB. The exposed edges of the LZMB are composed of CarboniferousPaleogene sedimentary rocks (sandstone, conglomerate, mudstone, limestone and shale), middle- and low-grade metamorphosed rocks (slate, phyllite and schist) and volcanic rocks. As an important part of the Lancangjiang magmatic belt, Indosinian intrusions such as the Dongdashan pluton (Peng et al., 2015), Jitang pluton (Tao et al., 2014) and Kagong pluton (Wang et al., 2018) are widely distributed, whereas Yanshanian and Himalayan intrusions are less developed in the LZMB (Fig. 2). The LZMB consists of abundant Cenozoic Pb-Zn-Sb-Ag deposits such as Lanuoma, Zhaofayong, Nanyuela and Ganzhongxiong (Tao et al., 2011; Liu et al., 2013; Luo et al., 2014) and Later Cretaceous W-Sn-Mo-Cu deposits (e.g. Larong W-Mo deposit, Dongpulu W-Sn-Cu deposit and Saibeinong Sn deposit; Shentu and Wang, 1991; Yong, 2007; Luo et al., 2014; Liu et al., 2019). 3. Deposit geology

The Larong porphyry W-Mo deposit is located ~50 km from the city of Zogang (Fig. 2). The Proterozoic Youxi Group and Lower Carboniferous Kagong Formation are the major lithostratigraphic units in this deposit (Fig. 3A). The Youxi Group is predominantly composed of quartz schist, metamorphosed quartz sandstone, sericite microcrystalline schist, quartz phyllite and quartzite. The Kagong Formation is mainly composed of metamorphosed sandstone, sand-slate, phyllite, quartzite and crystalline limestone. Faults are well developed in this deposit and are mainly NW- and nearly-EW-trending (Fig. 3A). The early NW-trending faults (F1 and F2) control the distribution of W-Mo orebodies, and the late nearly-EW-trending fault (F3) crosscuts the early faults and has little impact on W-Mo mineralization. Magmatic rocks in the Larong deposit mainly comprise monzogranite porphyry and granodiorite porphyry, and a small amount of porphyritic monzonite granite, granodiorite, granite and granitic aplite occur as dikes (Fig. 3). The W-Mo orebodies are mainly hosted in the monzogranite porphyry, granodiorite porphyry and surrounding quartz schist (Fig. 3B). Alteration is dominantly siliceous, phyllic, greisen and potassic, with local propylitic, carbonate and skarn assemblages. The alteration zonations, from the center of the monzogranite porphyry outward, can be roughly divided into the potassium zone, strong quartz-sericite (muscovite) zone and weak quartz-sericite-chlorite zone (Fig. 3B). Potassic alteration associated with W-Mo mineralization is present mostly in the monzogranite porphyry and porphyritic monzonite granite, and is typically identified by obvious fading alteration (Fig. 4E), with dark minerals such as biotite disappearing and plagioclase being altered to microcline or partly altered to potash feldspar, symbiotic with the biotite

(Fig. 4F). Strong quartz-sericite (muscovite) alteration is pervasively developed in the granodiorite porphyry and surrounding quartz schist within the middle part of the Larong deposit. It is closely associated with the extensive development of quartz, sericite, muscovite, molybdenite, pyrite, scheelite and fluorite (Fig. 4D). The weak quartz-sericite-chloritization zone surrounds the strong quartz-sericite (muscovite) zone, and displays relatively weak alteration and mineralization, characterized by the development of quartz, sericite, calcite, chlorite, pyrite and molybdenite (Fig. 4C-H and J). In addition, limonitization is widely distributed on the surface of this deposit (Fig. 4A), and hornfelization (Fig. 4B) and skarnization (Fig. 4G, K and L) occur in the contact zone between these porphyry intrusions and the quartz schist. Ore minerals of the Larong deposit mostly consist of scheelite, molybdenite, pyrite and chalcopyrite. Scheelite has a close symbiotic relationship with molybdenite, which occurs mainly in K-feldspar-quartz veins (Fig. 5A and B) with a euhedral-subhedral granular texture (Fig. 5G) and is sometimes metasomatized by molybdenite (Fig. 5H and Fig. 6C). Molybdenite is sparsely distributed in quartz veins and stockworks (Fig. 5C-E and Fig. 6A and B) and sulfide veins (Fig. 5F), occasionally coexisting with chalcopyrite (Fig. 5H). Pyrite is mainly scattered and disseminated in quartz veins (Fig. 5C-F and Fig. 6D-F) and commonly replaced by molybdenite (Fig. 5K and Fig. 6E and F). The gangue minerals are commonly composed of quartz, alkaline feldspar, sericite, muscovite, biotite, fluorite, chlorite, epidote and calcite (Figs. 5 and 6). Based on detailed field investigations, together with observed mineral assemblages and their crosscutting relationships, three mineralization stages have

been determined in the Larong deposit (Fig. 7): Stage I is the main W-mineralization stage, which consists of various quartz-scheelite ± K-feldspar veins (Fig. 5A-C). Stage II is the main Mo-mineralization stage, which is composed of various quartz-sulfide veins. This stage can be further subdivided into the quartz + molybdenite + pyrite + scheelite ± chalcopyrite stage (Stage II-1; Fig. 5C), the quartz + molybdenite + pyrite stage (Stage II-2; Fig. 5D and E) and the pyrite + molybdenite stage (Stage II-3; Fig. 5F). The paragenetic Stage III is characterized by development of barren quartzchlorite-carbonate veins. 4. Samples and analytical methods Samples were collected from four drill cores from the Larong deposit. Polished sections were prepared from numerous hand specimens, and examined with reflected light microscopy, and then with a scanning electronic microscope in order to confirm the composition of the sulfide minerals present. From these samples, six representative polished sections were selected for in-situ trace elemental and S-Pb isotopic analyses. The samples used in this study comprised one sample of stockwork ore with quartz + molybdenite + pyrite + scheelite ± chalcopyrite (LR-ZK0401-193) belonging to Stage II-1, four stockwork-disseminated ore samples with quartz + molybdenite + pyrite (LR-ZK0703-285, LR-ZK0303-289, LR-ZK0401-318, and LRZK0803-414) belonging to Stage II-2, and one scattered-veinlet ore sample with pyrite + molybdenite (LR-ZK0803-384) belonging to Stage III.

4.1 In-situ LA-ICPMS trace elemental analyses

Trace elemental analyses of sulfides were conducted by LA-ICPMS at the State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang. Laser sampling was performed using an ASI RESOLution-LR-S155 laser microprobe equipped with a Coherent Compex-Pro 193 nm ArF excimer laser (New Wave Research, ESI United Kingdom Electro Scientific Industries Europe Ltd, Huntingdon, Cambridge, UK). The laser was operated with a 26 μm diameter pit size, a 5 Hz pulse frequency and a 3 J/cm-2 fluence. An Agilent 7700x ICP-MS instrument was used to acquire ion-signal intensities. Helium (350 ml/min) was applied as a carrier gas. The ablated aerosol was mixed with argon gas (900 ml/min) as a transport gas, before exiting the cell. Each analysis incorporated a background acquisition of approximately 30 s (gas blank) followed by 60 s of data acquisition. The internal standard Py was used for calibration the concentrations of S and Fe. The integrated count data to concentrations for other elements were calibrated and converted by GSE-1G and GSD-1G. The preferred values of elemental concentrations for the USGS reference glasses are from the GeoReM database (http://georem.mpchmainz.gwdg.de/). Sulphide reference material MASS-1 was analyzed as an unknown sample to check the analytical accuracy.

4.2 In-situ S isotopic analysis

In-situ S isotopic analyses of pyrite, molybdenite and chalcopyrite were performed using a Nu II MC-ICPMS Instruments (Nu Instrument, Wrexham, UK) equipped with a

193 nm ArF excimer laser (Resonitics M50-LR Instrument, Australia) at the State Key Laboratory of Continental Dynamics (SKLCD), Northwest University, Xi’an. The laser power density was 3.5–4 J/cm2 with a frequency of ~3–4 Hz and a spot diameter of 30–37 μm. NBS123 (δ34SV-CDT = 17.8 ± 0.2‰), Py-4 (δ34SV-CDT = 1.7 ± 0.3‰) and Cpy-1 (δ34SV-CDT = 4.2 ± 0.3‰) were used as standards for isotopic fractionation correction. Each spot analysis consisted of ~60 s background acquisition and ~50 s sample data acquisition. The instrumental conditions and analytical processes were described in detail by Yuan et al. (2018).

4.3 In-situ Pb isotopic analysis

Because only molybdenite has a high contents of Pb (≥100ppm, Supplementary Table 1), which satisfies the requirements of quantitative analysis, the analyses of pyrite and chalcopyrite were not performed. In-situ Pb isotopic analysis of molybdenite was performed on a Nu II MC-ICPMS Instruments (Nu Instrument, Wrexham, UK) at the SKLCD. During the analysis, L4, L3, L2, L1, Ax, H1, and H2 Faraday cups were used to collect the

202Hg, 203Tl, 204Hg, 204Pb, 205Tl, 206Pb, 207Pb

and

208Pb

ion beams,

respectively. The solution was self-aspirated at an uptake rate of 100 μL min-1 through a standard PFA nebulizer and desolvated by the AridusTM. Solution standards of NIST NBS-981 adopted with NIST NBS-997 were measured during the same MC-ICPMS runs as the samples. The data were corrected for mass fractionation by normalizing to 205Tl/203Tl

= 2.3889, with an exponential law. Pb isotopic analyses consisted of 2 blocks

of 20 cycles per block with an integration time of 10 s per cycle. In this study, measured

values of NBS-981 were agreed well with the recommended values of 2.1674 ± 0.0005, 207Pb/204Pb

207Pb/206Pb

= 0.91486 ± 0.00025,

206Pb/204Pb

208Pb/206Pb

=

= 16.9397 ± 0.0111,

= 15.4974 ± 0.0089 and 208Pb/204Pb = 36.7147 ± 0.0262 (Yuan et al., 2018).

Finally, the Pb isotopic ratios were accurately determined after correction and were normalized to SRM 981. Details of instrument parameters and in-situ analysis techniques were described by Zhou et al. (2018). 5. Analytical results

5.1 In-situ LA-ICPMS trace elements

Results of in-situ LA-ICPMS trace elemental analyses for pyrite, molybdenite and chalcopyrite at the Larong deposit are presented in Supplementary Table 1. Upper crust-normalized trace element variation of the sulfides is shown in Fig. 8, and representative LA-ICPMS time-resolved depth profiles for sulfides, recorded during spot analysis, are shown in Fig. 9. Pyrite is rich in As and Se, with As content varying widely, from 0.18 ppm to 8058.88 ppm, with an average of 2452.61 ppm; Se content ranges from 1.86 ppm to 88.55 ppm with an average of 14.6 ppm. Pyrite is relatively enriched in Co and Bi, with measured concentrations varying widely, from 0.02 ppm to 1820.22 ppm with an average of 273.7 ppm and from 0.02 ppm to 12.07 ppm with an average of 3.44 ppm, respectively. Cu, Mo, Sn, W, Pb and Bi are low in most analyzed spots, and range from ppb-levels to several hundreds of ppm (Supplementary Table 1). Molybdenite is significantly rich in Pb (72.21–722.8 ppm), W (186.72–494.31 ppm),

Bi (53.49–899.56 ppm), Sb (1.2–18.14 ppm), Se (29.59–66.05 ppm) and Re (20.84– 46.69 ppm) with average concentrations of 337.23 ppm, 282.28 ppm, 321.84 ppm, 6.57 ppm, 44.49 ppm and 30.05 ppm, respectively. Molybdenite is also characterized by relative enrichment in As (1.34–132.01 ppm) and Cu (10.29–212.05 ppm), but depletion of Rb, Ag, Au, Zn and Mn. Chalcopyrite is rich in Bi (4.6–11.41 ppm), Sn (294.08–475.74 ppm), and Se (2.94–4.12 ppm) and depleted in Rb, Pb, W, Sb, As, Ag, Au, Zn, Mn Co and Ni.

5.2 In-situ S isotopic compositions

In-situ S isotopic compositions of sulfides at the Larong deposit are listed in Table 2. S isotopic results are expressed as δ34SVCDT = (Rsample/Rstandard - 1)×1000, where R is the ratio of

34S/32S,

reported as permil (‰) deviations from Vienna Canyon Diablo

Troilite (VCDT) standard. The majority of δ34SVCDT values of sulfides are concentrated in the range of 0.25–2.68‰ (Fig. 10B), with different sulfides showing different ranges: molybdenite (1.74–2.68‰, average 2.21‰) > pyrite (0.25–2.63‰, average 1.62‰) > chalcopyrite (0.46‰). This indicates that sulfur isotopic fractionation had reached a balance between various sulfides and H2S in the hydrothermal ore-forming system of the Larong deposit (Clayton, 2013).

5.3 In-situ Pb isotopic ratios

In-situ Pb isotopic ratios of molybdenite at the Larong deposit are given in Table 3. All samples have similar proportions of Pb isotopes (Fig. 12) with 207Pb/204Pb

and

206Pb/204Pb

208Pb/204Pb,

ratios of 39.356–39.908, 15.747–15.928 and 18.843–

20.120, respectively. The relative parameters of Pb isotopes calculated with the geochemical software Geokit (Lu, 2004) are also shown in Table 3. All samples have high μ, ω and Th/U values of 9.66–10.01, 35.26–40.90 and 3.47–3.97, respectively. 6. Discussion

6.1 The occurrence of trace elements in sulfides

Previous studies have indicated that trace elements occur in pyrite and other sulfides in three main forms: (1) as structurally bound elements (i.e., as solid solution within the crystal lattice (Reich et al., 2013), (2) as visible micro- to nanosized mineral inclusions (Thomas et al., 2011), and (3) within invisible nano-scale sulfides (Ciobanu et al., 2012). In addition to accurately obtaining the elemental concentrations, LAICPMS can also determine the occurrence of elements in minerals according to the spatial variation trend of elements with laser ablation depth (Cook et al., 1990; Palenik et al., 2004). Pyrite in the Larong deposit is characterized by enrichment of As, Se, Co and Bi, but depletion of Rb, Pb, W, Sn, Ag, Au, Zn and Mn (Fig. 8). In the time-resolved LAICPMS spectra (Fig. 9A), the signals of Co, Ni and As are generally smooth and consistent with that of Fe, which indicates that these siderophile and chalcophile elements are commonly distributed in pyrite via isomorphism (Belousov et al., 2016). The concentrations of Cu, Mo, Sn, W, Pb and Bi are low in most analyzed spots, and range from ppb-levels to a few hundreds of ppm (Supplementary Table 1), indicating that these elements are distributed primarily as microinclusions or mechanical mixtures.

Molybdenite is extremely rich in Pb, W, Bi, Sb, Se and Re (Supplementary Table 1), but depleted in Rb, Ag, Au, Zn and Mn (Fig. 8). Mo in molybdenite mainly exists as Mo4+, and has a similar ionic radius and ionic charge to Re4+, W4+, Sn4+, Ta5+, Ta4+, Mn3+ and Ti3+. The similarly flat time-resolved depth profiles for Re and Mo (Fig. 9B) indicate that Re4+ is likely to have replaced Mo4+ through isomorphism (Takahashi et al., 2007). W also shares a similar spectra with Mo (Fig. 9B), however, as an oxyphilic element, W usually exists in the oxidized state of W6+, and thus it is difficult for W6+ to occupy the position of Mo4+ in molybdenite (Huang et al., 2014), W may therefore occur as nano-scale scheelite grains or as inclusions of a size that cannot be resolved by the laser (submicrometer particles). The other elements show different patterns (Fig. 9B), indicating that they were likely formed by mechanical mixing or occur as mineral inclusions in molybdenite. Chalcopyrite is characterized by enrichment in Se, Sn and Bi, but depletion in Rb, Pb, W, Sb, As, Ag, Au, Zn, Mn, Co and Ni (Fig. 8). In the time-resolved LA-ICPMS spectra, only Sn shares a similar signal distribution with Cu (Fig. 9C). However, as a typical oxyphilic element, Sn usually exists as Sn4+ so that it is unlikely to occupy the position of Cu2+ or Fe2+ in chalcopyrite (Huang et al., 2014). Sn maybe exist in chalcopyrite as nano-scale cassiterite grains or micro/nano-scale inclusions. In short, Co and As are extremely enriched in pyrite, molybdenite is remarkably rich in W, Pb and Bi, and chalcopyrite is characterized by high Sn contents. These facts are consistent with the mineralization characteristics of the Larong deposit, where the main metallogenic elements are W and Mo, accompanied by Bi, Sn and Cu.

6.2 Sources of ore-forming materials

6.2.1 Constraints from in-situ S isotopes

Due to isotopic fractionation between liquid and solid phases during the hydrothermal ore-forming process, the δ34S values of sulfides are not equal to the total δ34S values of the hydrothermal fluid, but are a function of the total δ34S values, fO2, PH, ionic strength and temperature (Ohmoto, 1972). However, under conditions of low oxygen fugacity, the δ34S values of sulfides are generally equal to the total δ34S values of the hydrothermal fluid (Ohmoto, 1972). By combining the field investigations and microscopic identification, it has been confirmed that the Larong deposit is free of sulphate minerals, and is mainly composed of molybdenite, pyrite and chalcopyrite, indicating a relatively low oxygen fugacity condition. The δ34S values of the sulfides are therefore roughly equivalent to the total δ34S values of the hydrothermal fluid. The δ34SVCDT values of sulfides in the Larong deposit range from 0.25‰ to 6.37‰, with a mean of 2.15‰ (Fig. 10B). Unlike sedimentary rocks, which usually have a negative or wide range of δ34SVCDT values (Fig. 10D; Seal, 2006), the δ34SVCDT values of sulfides in the Larong deposit are relatively concentrated, and slightly above the range of the mantle sulfur (0 ± 2‰; Thode et al, 1961), indicating a predominantly magmatic origin for sulfur. The δ34SVCDT values of Stage II-1 pyrite are concentrated between 0.25‰ and 0.47‰, consistent with that of chalcopyrite (0.46‰); Stage II-2 pyrite has δ34SVCDT values ranging from 0.72‰ to 2.5‰, mostly consistent with those of molybdenite (1.74‰–2.68‰); Stage II-3 pyrite has a wide range of δ34SVCDT values,

from 4.52‰ to 6.37‰. From Stage II-1, to Stage II-2, to Stage II-3, the average δ34S values of pyrite changed from 0.33‰, to 1.88‰, to 5.34‰ (Fig. 11). This suggests a homogenous sulfur source and evolutionary trend, implying magmatic control on WMo mineralization in the Larong deposit (Hu et al., 2019).

6.2.2 Constraints from in-situ Pb isotopes

Sulfides show similar Pb isotopic compositions, with 208Pb/204Pb, 207Pb/204Pb and 206Pb/204Pb

values of 39.356–39.908, 15.747–15.928 and 18.843–20.120, respectively.

Because these sulfides are nearly free of U and Th, and almost no radiogenic Pb was generated after mineral formation, these Pb isotopic compositions likely reflect the initial Pb isotopic compositions of the ore-forming hydrothermal fluid, thus tracking its source (Zhang et al., 2000; Zhou et al., 2016; Zhou et al., 2018). In the Pb isotopic system, due to the differences in partition coefficients between U, Th and Pb in the upper crust, lower crust and mantle, the μ and ω values and Th/U ratios of the samples can be used, to a certain degree, to distinguish the three reservoirs (Doe and Stacey, 1974). The μ values of sulfides at the Larong deposit are relatively concentrated (9.66– 10.01), and are higher than the average value of the upper crust (9.58). The ω values of sulfides are between 35.26 and 40.90. The majority of these values are higher than the average value of the crust (36.84), and a few are lower than this value. The Th/U ratios of sulfides vary from 3.47 to 3.97, between the average values of the mantle (3.45) and upper crust (3.88). These isotopic parameters characteristics indicate a predominantly upper crustal source for Pb, with a small contribution from the mantle or

juvenile lower crust. This argument is also supported by the fact that almost all samples plot in the upper crust fields in the 207Pb/204Pb–206Pb/204Pb diagram (Fig. 12A) and the Δβ–Δγ Pb parameters diagram (Fig. 12B).

6.2.3 Constraints from in-situ trace elements

The Re-Os isotopic system can provide not only precise constraints on the age of metallic ore deposits, but also a highly sensitive monitor of possible metal sources (Foster et al., 1996; Mao et al., 1999, 2008). As an extremely dispersive element, Re does not easily form independent minerals in nature, and often occupies the position of Mo4+ in molybdenite though isomorphism (Takahashi et al., 2007). The molybdenite related to mantle-derived materials commonly has a higher Re content, while the molybdenite associated with crust-derived materials usually has a lower Re content (Stein et al., 2001; Berzina et al., 2005). For example, the Re content in molybdenite decreases from several hundred ppm in the mantle source, to tens of ppm in the crustmantle mixed source, and to several ppm in the crustal source (Mao et al., 1999). The Re content of molybdenite from the Larong deposit ranges from 20.84 ppm to 46.69 ppm, indicating a predominantly crustal source, mixed with a small amount of material derived from the mantle or juvenile lower crust. The precipitation rate of Ni is lower than that of Fe, thus Ni can easily enter the crystal lattice of pyrite, and is less active in a reduced condition, so the Ni content of pyrite can provide important information for the source of ore-forming materials (Large et al., 2009). Ni is a siderophile element, which can be strongly enriched in the basic-

ultrabasic rocks. For example, the Ni content of mantle rocks can be up to 2200 ± 500 ppm (Palme and O'Neill, 2003). Therefore, if Ni in pyrite is derived from basic-ultrabasic rocks, then the Ni content should be relatively high. In contrast, pyrite derived from felsic rocks, such as highly differentiated granite, usually has a very low Ni content. In this study, the Ni content of most pyrites is less than the average value of the continental crust (59 ppm; Rudnick and Gao, 2003), although some individual pyrites have a high Ni content (up to several hundred ppm), implying that the ore-forming materials were mainly derived from the continental crust with a small contribution from the mantle or juvenile lower crust. In addition, the Re-Os weighted average age of 91.8 Ma (Liu et al., 2019) is consistent with the zircon U-Pb age (93.9 Ma) of the MP, and high-temperature alteration and disseminated mineralization are well developed in the MP of the Larong deposit (Fig. 5F). Hence, we propose that the Larong W-Mo deposit is genetically related to the MP, but whether or not other endmembers (e.g. GP and surrounding quartz schist) have contributed to mineralization, and the degree of contribution, remain to be resolved.

6.3 Implications for ore-forming processes

In contrast to other metals (e.g. Cu, Au, Mo and Sn) that are transported as metal ions complexed with anionic ligands such as Cl- or HS- in hydrothermal fluids, W is transported as part of an oxyanion, WO42-. Precipitation of the main tungstate mineral scheelite, CaWO4, thus depends on the availability of calcium (Lecumberri-Sanchez et

al., 2017). This brings up an interesting point of how scheelite and molybdenite precipitate together. Pyrite is a ubiquitous mineral phase in the Larong deposit, accompanied by W-Mo mineralization, and thus provides a window for tracing the oreforming process. From Stage II-1, to Stage II-2, to Stage II-3, the average δ34S values of pyrite change from 0.33‰, to 1.88‰, to 5.34‰. This increasing trend may indicate that chemical reactions between the magmatic fluid and wall rocks along the fracture induced the gradual decreasing of oxygen fugacity and temperature (Ohmoto, 1979; Neumayr et al., 2008; Ward et al., 2017), and the mineralization of W and Mo occurred successively. The detailed ore-forming processes are as follows: 1) During the Later Cretaceous, fault-controlled emplacement of magma generated the Larong monzogranite porphyry (Liu et al., 2019), which continued to cool and crystallize to form the W- and Mo-rich fluid. 2) As the fluid ascended, it filtered through and reacted with the cooling porphyry rocks, causing K-silicate alteration, whereby plagioclase was altered into K-feldspar and released abundant Ca2+, and subsequently combined with HWO4- or WO42- to form scheelite during Stage I. However, the fluid during Stage I was relatively hightemperature, oxidized and poor in S2-, thus unfavorable for sulfide deposition

(Yang

et al., 2012). 3) As the water-rock reaction continued, the fluid became more lower-temperature, acidic, reduced and rich in S2- (Ward et al, 2017). This change facilitated the deposition of sulfides (e.g. molybdenite, pyrite) together with quartz, forming the Stage II quartzmolybdenite-pyrite stockworks (Yang et al., 2012). Meanwhile, plagioclase was altered

to sericite or muscovite and released abundant Ca2+, then combined with remaining HWO4- or WO42- to form a small quantity of scheelite in Stage II-1. 4) Finally, after precipitation of scheelite and molybdenite, a small amount of pyrite was formed in Stage III.

6.4 Implications for the regional mineralization

The BNMB is an important metallogenic belt in China, and previously discovered deposits in this belt mainly consist of Cu-Au deposits (Li et al., 2016, 2017a; Zhu et al., 2017; Zhang et al., 2018) and Fe-Cu polymetallic deposits (Wang et al., 2012; Li et al., 2013b). As the first giant W-Mo deposit in eastern Tibet, the discovery of the Larong W-Mo deposit not only broadens the scope of the BNMB, but also suggests a giant Wpolymetallic metallogenic potential in the BNMB (Shentu and Wang, 1991; Yong, 2007; Luo et al., 2014; Liu et al., 2019). Through combing our latest geochronology data (Liu et al., 2019) with previous research results (Table 1), a total of four metallogenic events (Fig. 13) have been identified in the BNMB. Apart from the Early Jurassic (185–190 Ma), W-polymetallic deposits are well developed in the remaining three stages: 1) the Late Jurassic (155–170 Ma) (Songmo W deposit; Geng et al., 2012; Li et al., 2014a, 2014b); 2) the Early Cretaceous (110–125 Ma) (Shilong W deposit; Geng et al., 2012; Li et al., 2014a); 3) the Late Cretaceous (100–75 Ma) (e.g. Larong W-Mo deposit; Luo et al., 2014; Liu et al., 2019). W-polymetallic mineralization was the most intense in the Late Cretaceous (100–75 Ma), supporting the viewpoint that porphyry W deposits are mainly formed under intra-continental and post-collisional settings, and the conjunction

zone of ancient structures is an important control on the distribution of porphyry W deposits (Mao et al., 2013). In terms of spatial distribution, Cu-Au deposits occur mainly in the western section of the BNMB, while Fe-Cu polymetallic deposits occur mainly in the middle and western sections of the BNMB, and W-Sn-Mo deposits are mainly distributed within the eastern section of the BNMB (Fig. 1B). Here S and Pb isotopes of the above-mentioned three types of deposits are compared. It is found that the δ34SVCDT values of Cu-Au deposits vary from -9.9‰ to 6.8‰ (Fig. 10A), and are concentrated between -3‰ and 4‰, indicating a predominant mantle source, with a small amount of crustal contamination (Zhao et al., 2011; Yao et al., 2012; Bai et al., 2015; Zhang et al., 2015; Wang et al., 2017; Li et al., 2018b). This argument is also supported by the Pb isotopic compositions (Fig. 13), which indicate a crust-mantle mixed source. The δ34SVCDT values of the Larong W-Mo deposit concentrate in the range of 0.25–2.68‰ (Fig. 11B), supporting the view that W-polymetallic deposits are generally related to transitional magnetiteand ilmenite-series granites (Blevin, 2010). The δ34SVCDT values of Fe-Cu deposits vary from -0.6‰ to 11.1‰, are concentrated between 4‰ and 6‰ (Fig. 10C), and commonly have a genetic relationship with magnetite-series granites (Blevin, 2010), which can be attributed to the remelting of igneous rocks (Yu et al., 2011; Wu et al., 2018). The

207Pb/204Pb

and Δβ values increase linearly with the

206Pb/204Pb

and Δγ

values (Fig. 12), respectively, revealing the gradual increase in the involvement of crustal materials from Cu-Au deposits, to Fe-Cu deposits and W-Mo deposits in the BNMB. These research results clearly show that these ore-forming materials were

closely related to relevant magmatism. Similar to the Lhasa terrane (Hou et al., 2015), the spatial variation of different types of deposits in the BNMB is likely to be constrained by the lithospheric architecture. 7. Conclusion (1) Pyrite is rich in Co and As, molybdenite is characterized by the enrichment of W, Pb and Bi, and chalcopyrite has high Sn contents. (2) The ore-forming materials were mainly derived from the continental crust with a small contribution from the mantle or juvenile lower crust. (3) With the decrease of temperature and oxygen fugacity of ore-forming fluid, the mineralization of W and Mo occurred successively. (4) Our study led to the identification of three W-dominated polymetallic metallogenic events and mineralization potential of igneous rocks in the BNMB. Acknowledgements This research was supported by the Commonwealth Project from Yunnan Science and Technology Award-Outstanding Contribution Award (2017001), China Geological Survey (DD20179604 and DD20160016) and the International Megascience Research Program of Chengdu Center of China Geological Survey. We thank Yu Dong and Jianghua Wu from the No. 6 Geological Party, Tibet Bureau of Geology and Mineral Resources Exploration, for invaluable assistance during field work. We are grateful to Dr. Kaiyun Chen and Dr. Zhian Bao from the Continental Dynamics Laboratory of Northwest University for their help with in-situ S-Pb isotopic analyses and Zhihui Dai from the Institute of Geochemistry, Chinese Academy of Sciences for her assistance

with the LA-ICPMS trace element analysis of sulfides. We also appreciate the kind help of Wanhua Cheng from the Chengdu Center of China Geological Survey for his immense help with sample preparation. Gratitude is also expressed to the Chief Editor, Mei-Fu Zhou, and two anonymous reviewers for their constructive comments and excellent suggestions that greatly improved the paper.

References Bai, Y., Zhang, Z., Chen, Y.C., Tang, J.X., He, L., Yang, Y., 2015. S, Pb isotope geochemical

characteristics

of

the

Gaerqiong-Galale

gold-copper

ore-

concentrated area. Metal Mine 44, 100–104 (in Chinese with English abstract). Belousov, I., Large, R.R., Meffre, S., Danyushevsky, L.V., Steadman, J., Beardsmore, T., 2016. Pyrite compositions from VHMS and orogenic Au deposits in the Yilgarn Craton, Western Australia: Implications for gold and copper exploration. Ore Geology Reviews 79, 474–499. Berzina, A.N., Sotnikov, V.I., Economou-Eliopoulos, M., Eliopoulos, D.G., 2005. Distribution of rhenium in molybdenite from porphyry Cu-Mo and Mo-Cu deposits of Russia (Siberia) and Mongolia. Ore Geology Reviews 26, 91–113. Blevin, P.L., 2010. Redox and compositional parameters for interpreting the granitoid metallogeny of eastern Australia: Implications for gold-rich ore systems. Resource Geology 54, 241–252. Cao, H.W., Zhang, Y.H., Pei, Q.M., Zhang, R.Q., Tang, L., Lin, B., Cai, G.J., 2017. UPb dating of zircon and cassiterite from the Early Cretaceous Jiaojiguan iron-tin

polymetallic deposit, implications for magmatism and metallogeny of the Tengchong area, western Yunnan, China. International Geology Review 59, 234– 258. Cao, H.W., Zhang, Y.H., Santosh, M., Li, G.M., Hollis, S.P., Zhang, L.K., Pei, Q.M., Tang, L., Duan, Z.M., 2019. Petrogenesis and metallogenic implications of Cretaceous magmatism in Central Lhasa, Tibetan Plateau: A case study from the Lunggar Fe skarn deposit and perspective review. Geological Journal. In press, doi: 10.1002/gj.3299. Cao, M.J., Qin, K.Z., Li, G.M., Li, J.X., Zhao, J.X., Evans, N. J., Hollings, P., 2016. Tectono-magmatic evolution of Late Jurassic to Early Cretaceous granitoids in the west central Lhasa subterrane, Tibet. Gondwana Research 39, 386–400. Chen, S.H., Wang, B., Zhang, J.R., Luo, X., Niu, J.Z., Du, C.F., Wan, C., 2014. Lithogeochemical Characteristics and Chronology of Fuye Granitic Pluton from the Western Bangong-Nujiang Metallogenic Belt in China. Journal of East China Institute of Technology 37, 37–44 (in Chinese with English abstract). Clayton, R.N., 2013. Stable isotope geochemistry. Eos Transactions American Geophysical Union, 52, IUGG–IUGG 110. Ciobanu, C.L., Cook, N.J., Utsunomiya, S., Kogagwa, M., Green, L., Gilbert, S., Wade, B., 2012. Gold-telluride nanoparticles revealed in arsenic-free pyrite. American Mineralogist 97, 1515–1518. Cook, N.J., Chryssoulis, S.L., 1990. Concentrations of invisible gold in the common sulfides. The Canadian Mineralogist 28, 1–16.

Ding, L., Zhao, Y.Y., Yang, Y.Q., Cui, Y.B., Lv, L.N., 2012. LA-ICPMS zircon U-Pb dating and geochemical characteristics of ore-bearing granite in skarn-type iron polymetallic deposits of Duoba area, Baingoin County, Tibet, and their significance: Acta Petrologica et Mineralogica 31, 479–496 (in Chinese with English abstract). Doe, B.R., Stacey, J.S., 1974. Application of lead isotopes to the problems of ore genesis and ore prospect evaluation: a review. Economic Geology 69, 757–776. Dong, L., Li, G.M., Huang, H.X., Yong, Y.Y., 2013. Geochemical characteristics, chronology and the significance of Laqing copper polymetallic skarn deposit, Bange county, Tibet. Geological Bulletin of China 32, 767–773 (in Chinese with English abstract). Duan, Z.M., Li, G.M., Zhang, H., Li, Y.X., Duan, Y.Y., 2013. Zircon U-Pb age, geochemical characteristics of the quartz monzobiorite and metallogenic background of the Sena gold deposit in Duolong metallogenic concentrated area, Tibet. Journal of Jilin University (Earth Science Edition) 43, 1864–1877 (in Chinese with English abstract). Fang, X., Tang, J.X., Song, Y., Yang, C., Ding, S., Wang, Y.Y., Wang, Q., Sun, X.G., Li, Y.B., Wei, L.J., Zhang, Z., Yang, H.H., Gao, K., Tang, P., 2015. Formation epoch of the South Tiegelong superlarge epithermal Cu (Au-Ag) deposit in Tibet and its geological implications. Acta Geosci. Sin. 36, 168–176 (in Chinese with English abstract). Foster, J.G., Lambert, D.D., Frick, L.R., 1996. Re-Os isotopic evidence for genesis of

Archaean nickel ores from uncontaminated komatiites. Nature 382, 703–706. Gao, K., Tang, J.X., Fang, X., Zhang, Z., Wang, Q., Yang, H.H., Wang, Y.Y., Feng, J., 2016. Geological and geochemical characteristics and significance of the Sena Cu-Au deposit from Duolong ore-concentration area, Tibet, China. Acta Mineralogica Sinica 36, 199–207 (in Chinese with English abstract). Gao, S., Luo, T.C., Zhang, B.R., Zhang, H.F., Han, Y.W., Zhao, Z.D., Hu, Y.K., 1998. Chemical composition of the continental crust as revealed by studies in East China. Geochimica et Cosmochimica Acta 62, 1959–1975. Geng, Q.R., Peng, Z.M., Zhang, Z., Pan, G.T., Wang, L.Q., Guan, J.L., Jia, B.J., Diao, Z.Z., 2012. Tethyan evolution and geological background of the Bangong CoNujiang metallogenetic zone and adjacent region. Geological Publishing House, Beijing, pp.1–230 (in Chinese). Geng, Q.R., Zhang, Z., Peng, Z.M., Guan, J.L., Zhu, X.P., and Mao, X.C., 2016. Jurassic-Cretaceous granitoids and related tectono-metallogenesis in the ZapugDuobuza arc, western Tibet. Ore Geology Reviews 77, 163–175. He, H.Y., Li, Y.L., Wang, C.S., Han, Z.P., Ma, P.F., Xiao, S.Q., 2019. Petrogenesis and tectonic implications of Late Cretaceous highly fractionated I-type granites from the Qiangtang block, central Tibet. Journal of Asian Earth Sciences 176, 337– 352. Hou, Z.Q., Zaw, K., Pan, G.T., Mo, X.X., Xu, Q., Hu, Y.Z., Li, X.Z., 2007. Sanjiang Tethyan metallogenesis in SW China: Tectonic setting, metallogenic epochs and deposit types. Ore Geology Reviews 31, 48–87.

Hu, X.K., Tang, L., Zhang, S.T., Santosh, M., Spencer, C.J., Zhao, Y., Cao, H.W., Pei, Q.M., 2019. In situ trace element and sulfur isotope of pyrite constrain ore genesis in the Shapoling molybdenum deposit, East Qinling Orogen, China. Ore Geology Reviews 105, 123–136. Huang, H.X., Gong, F.Z., Li, G.M., Liu, H., Chen, H.A., Zhu, X.P., Xiao, W.F., 2016. Zircon U-Pb age and geochemical features of the early cretaceous Purang Pluton on the southern margin of Qiangtang, Xizang (Tibet), and their geological implications. Geological Review 62, 569–584 (in Chinese with English abstract). Huang, H.X., Li, G.M., Chen, H.A., Shi, H.Z., Liu, B., Zhu, X. P., Zeng, Q.G., Li, Z., 2013. Molybdenite Re-Os isotope age and metallogenic significance of Sebuta copper molybdenum deposit in Tibet. Acta Geologica Sinica 87, 240–244 (in Chinese with English abstract). Huang, H.X., Li, G.M., Liu, B., Dong, S.L., Shi, H.Z., Zhang, Z.L., and Fan, A.H., 2012. Zircon U-Pb geochronology and geochemistry of the Tiangongnile skarn-type CuAu deposit in Zhongba County, Tibet: Their genetic and tectonic setting significance. Acta Geoscientica Sinica 33, 424–434 (in Chinese with English abstract). Huang, F., Wang, D.H., Chen, Y.C., Wang, C.H., Tang, J.X., Chen, Z.H., Wang, L.Q., Liu, S.B., Li, J.K., Zhang, C.Q., Ying, L.J., Wang, Y.L., Li, L.X., Li, C., 2014. Trace elements characteristics of molybdenites from endogenous molybdenum deposits in China. Mineral Deposits 33, 1193–1212 (in Chinese with English abstract). Large, R.R., Danyushevsky, L., Hollit, C., Maslennikov, V., Meffre, S., Gilbert, S., Bull,

S., Scott, R., Emsbo, P., Thomas, H., 2009. Gold and trace element zonation in pyrite using a laser imaging technique: Implications for the timing of gold in orogenic and Carlin-style sediment-hosted deposits. Economic Geology 104, 635–668. Lecumberri-Sanchez, P., Vieira, R., Heinrich, C.A., Pinto, F., Wälle, M., 2017. Fluidrock interaction is decisive for the formation of tungsten deposits. Geology 45, 579–582. Li, G.M., Qin, K.Z., Li, J.X., Evans, N.J., Zhao, J.X., Cao, M.J., Zhang, X.N., 2017b. Cretaceous magmatism and metallogeny in the Bangong-Nujiang metallogenic belt, central Tibet: Evidence from petrogeochemistry, zircon U-Pb ages, and HfO isotopic compositions. Gondwana Research 41, 110–127. Li, J.X., Qin, K.Z., Li, G.M., Evans, N.J., Zhao, J.X., Cao, M.J., Huang, F., 2016b. The Nadun Cu-Au mineralization, central Tibet: root of a high sulfidation epithermal deposit. Ore Geology Reviews 78, 371–387. Li, J.X., Qin, K.Z., Li, G.M., Richards, J.P., Zhao, J.X., Cao, M.J., 2014a. Geochronology, geochemistry, and zircon Hf isotopic compositions of Mesozoic intermediate-felsic intrusions in central Tibet: petrogenetic and tectonic implications. Lithos 198–199, 77–91. Li, J.X., Qin, K.Z., Li, G.M., Xiao, B., Zhao, J.X., Cao, M.J., and Chen, L., 2013a. Petrogenesis of ore-bearing porphyries from the Duolong porphyry Cu-Au deposit, central Tibet: Evidence from U-Pb geochronology, petrochemistry and Sr-Nd-HfO isotope characteristics: Lithos 160–161, 216–227.

Li, J.X., Qin, K.Z., Li, G.M., Xiao, B., Zhao, J.X., Chen, L., 2016a. Petrogenesis of Cretaceous igneous rocks from the Duolong porphyry Cu-Au deposit, central Tibet: evidence from zircon U-Pb geochronology, petrochemistry and Sr-Nd-PbHf isotope characteristics. Geological Journal 51, 285–307. Li, S.M., Zhu, D.C., Wang, Q., Zhao, Z.D., Sui, Q.L., Liu, S.A., Liu, D., Mo, X.X., 2014b. Northward subduction of Bangong-Nujiang Tethys: insight from Late Jurassic intrusive rocks from Bangong Tso in western Tibet. Lithos 205, 284– 297. Li, S.R., Xiao, R., Zhou, S., Mo, X.X., Shen, J.F., Yan, B.K., and Liu, B., 2005. Gold mineralization in Gaize area, Tibet: Mineral Deposits 24, 1–14 (in Chinese with English abstract). Li, X.K., Chen, J., Wang, R.C., Li, C., 2018a. Temporal and spatial variations of Late Mesozoic granitoids in the SW Qiangtang, Tibet: Implications for crustal architecture, Meso-Tethyan evolution and regional mineralization. Earth-Science Reviews 185, 374–396. Li, X.K., Li, C., Sun, Z.M., Wang, M., 2017a. Origin and tectonic setting of the giant Duolong Cu-Au deposit, South Qiangtang Terrane, Tibet: evidence from geochronology and geochemistry of Early Cretaceous intrusive rocks. Ore Geology Reviews 80, 61–78. Li, X.S., Zhao, Y.Y., Wang, J.P., Xu, H., 2013b. Geochemical characteristics, chronology and significance of Gengnai skarn-type iron polymetallic deposit, Tibet. Acta Geologica Sinica 87, 1679–1693 (in Chinese with English abstract). Li, X.Y., Chen, W., Qu, X.M., Ma, X.D., 2018b. S, Pb isotopic characteristics of

Xiongmei porphyry copper deposit in Tibet and their metallogenic significance. Mineral Deposits 37, 643–655 (in Chinese with English abstract). Li, Z.J., Zhao, R.D., He, Z.X., Zhang, Z., Li, P.R., You, M., He, S., Guo, Q.Q., Ou, J., 2017c. Source of ore-forming materials in the Galale copper-gold deposit of Tibet: Evidence from geochemical characteristics of sulfur, lead, carbon and hydrogenoxygen isotopes. Acta Geoscientica Sinica 38, 651–658 (in Chinese with English abstract). Lin, B., Chen, Y.C., Tang, J.X., Song, Y., Wang, Q., Feng, J., Li, Y.B., Tang, X.Q., Lin, X., Liu, Z.B., Wang, Y.Y., Fang, X., Yang, C., Yang, H.H., Fei, F., Li, L., Gao, K., 2016. Zircon U-Pb ages and Hf isotopic composition of the ore-bearing porphyry in Dibao Cu (Au) deposit, Duolong ore concentration area, Xizang (Tibet), and its geological significance. Geological Review 62, 1565–1578 (in Chinese with English abstract). Lin, B., Tang, J.X., Chen, Y.C., Song, Y., Hall, G., Wang, Q., Yang, C., Fang, X., Duan, J.L., Yang, H.H., Liu, Z.B., Wang, Y.Y., Feng, J., 2017. Geochronology and genesis of the Tiegelongnan porphyry Cu (Au) deposit in Tibet: Evidence from UPb, Re-Os dating and Hf, S, and H-O isotopes. Resource Geology 67, 1–21. Liu, D.L., Shi, R.D., Ding, L., Huang, Q.S., Zhang, X.R., Yue, Y.H., Zhang, L.Y., 2017. Zircon U-Pb age and Hf isotopic compositions of Mesozoic granitoids in southern Qiangtang, Tibet: Implications for the subduction of the Bangong-Nujiang Tethyan Ocean. Gondwana Research 41, 157–172. Liu, D.L., Shi, R.D., Ding, L., Zou, H.B., 2018. Late Cretaceous transition from

subduction to collision along the Bangong-Nujiang Tethys: New volcanic constraints from central Tibet. Lithos 296, 452–470. Liu, J., Zhu, X.P., Li, W.C., Wang, B.D., Dong, Y., Yang, F.C., Yang, H.B., Wu, J.H., 2019. Molybdenite Re-Os dating of the Larong porphyry W-Mo deposit in eastern Tibet and its geological significance. Acta Geological Sinica 93 (in Chinese with English abstract). Liu, W.B., Zhao, J.M., Ji, Q.H., Zhang, M.Y., Zhao, K., Liu, C.Q., 2014. Geological characteristics and petrogenesis of the Zhagela gold deposit in Dingqing, Tibet. Chinese Journal of Geology 49, 1169–1183 (in Chinese with English abstract). Liu, Y.C., Hou, Z.Q., Yu, Y.S., Tian, S.H., Li, Y.L., Yang, Z.S., 2013. Characteristics and genesis of Lalongla MVT-like deposit in Changdu region, Tibet. Acta Petrologica Sinica 29, 1407–1426 (in Chinese with English abstract). Lu, Y., Zhang, J.S., Chen, H.Q., 2012. A Brief Introduction to the mineral resources in the middle and western part of the Bangong-Nujiang Metallogenic Belt. Tibet Geol. 33, 47–54 (in Chinese with English abstract). Lu, Y.F., 2004. GeoKit—A geochemical toolkit for Microsoft Excel. Geochimica 33, 459–464 (in Chinese with English abstract). Ludwig K R. 2003. Users manual for ISOPLOT/EX, version 3. A geochronological toolkit for Microsoft Excel. Berkeley Geochronology Center Special Publication. Luo, M., Pan, F.C., Li, J.C., Xu, Z.Z, Deng, W.Z., Li, G.Q., Liu, L.J., 2014. Metallogenic series study of ore deposits in the Tibet Qiangtang-Sanjiang district. Acta Geological Sinica 88, 2556–2571 (in Chinese with English abstract).

Lv, L,N., Zhao, Y.Y., Song, L., Tian, Y., Xin, H.B., 2011. Characteristics of C, Si, O, S and Pb isotopes of the Fe-rich and Cu (Au) deposits in the western BangongNujiang metallogenic belt, Tibet, and their geological significance. Acta Geologica Sinica 85, 1291–1304 (in Chinese with English abstract). Mao, J.W., Cheng, Y.B., Chen, M.H., Pirajno, F., 2013. Major types and time-space distribution of mesozoic ore deposits in south china and their geodynamic settings. Mineralium Deposita 48, 267–294. Mao, J.W., Xie, G.Q., Bierlein, F., Ye, H.S., Qu, W.J., Du, A.D., Pirajno, F., Li, H.M., Guo, B.J., Li, Yongfeng, Yang, Z.X., 2008. Tectonic implications from Re-Os dating of Mesozoic molybdenum deposits in the East Qinling-Dabie orogenic belt. Geochimica Et Cosmochimica Acta 72, 4607–4626. Mao, J.W., Zhang, Z.C., Zhang, Z.H., Du, A.D., 1999. Re-Os isotopic dating of molybdenites in the Xiaoliugou W (Mo) deposit in the northern Qilian mountains and its geological significance. Geochimica Et Cosmochimica Acta 63, 1815– 1818. Metcalfe, I., 2013. Gondwana dispersion and Asian accretion: Tectonic and palaeogeographic evolution of eastern Tethys. Journal of Asian Earth Sciences 66, 1–33. Miller, C.H., Schuster, R., Klötzli, U., Frank, W., Purtscheller, F., 1999. Post-collisional potassic and ultrapotassic magmatism in SW Tibet: geochemical and Sr-Nd-PbO isotopic constraints for mantle source characteristics and petrogenesis. Journal of Petrology 40, 1399–1424.

Neumayr, P., Walshe, J., Hagemann, S., Petersen, K., Roache, A., Frikken, P., Horn, L., Halley, S., 2008. Oxidized and reduced mineral assemblages in greenstone belt rocks of the st. ives gold camp, western australia: vectors to high-grade ore bodies in archaean gold deposits?. Mineralium Deposita 43, 363–371. Ohmoto, H., 1972. Systematics of sulfur and carbon isotopes in hydrothermal ore deposits. Economic Geology 67, 551–578. Palenik, C.S., Utsunomiya, S., Reich, M., Kesler, S.E., Wang, L., Ewing, R.C., 2004. “Invisible” gold revealed: Direct imaging of gold nanoparticles in a Carlin-type deposit. American Mineralogist 89, 1359–1366. Palme, H., O'Neill, H.S.C., 2007. Cosmochemical estimates of mantle composition. Treatise on Geochemistry, 1–38. Pan, G.T., Wang, L.Q., Li, R.S., Yuan, S.H., Ji, W.H., Yin, F.G., Zhang, W.P., Wang, B.D., 2012. Tectonic evolution of the Qinghai-Tibet Plateau. Journal of Asian Earth Sciences 53, 3–14. Peng, T.P., Zhao, G.C., Fan, W.M., Peng, B.X., Mao, Y.S., 2015. Late Triassic granitic magmatism in the Eastern Qiangtang, Eastern Tibetan Plateau: Geochronology, petrogenesis and implications for the tectonic evolution of the Paleo-Tethys. Gondwana Research 27, 1494–1508. Peng, Y.B., Yu, S.Y., Li, S.Z., Liu, Y.J., Dai, L.M., Lv, P., Guo, R.H., Liu, Y.M., Wang, Y.H., Xie, W.M., 2019. Early Jurassic and Late Cretaceous granites in the Tongka micro-block, Central Tibet: Implications for the evolution of the Bangong-Nujiang ocean. Journal of Asian Earth Sciences, 104030.

Qu, X.M., Wang, R.J., Dai, J.J., Li, Y.G., Qi, X., Xin, H.B., Song, Y., Du, D.D., 2012. Discovery of Xiongmei porphyry copper deposit in middle segment of Bangonghu-Nujiang suture zone and its significance. Mineral Deposits 31, 1–12 (in Chinese with English abstract). Qu, X.M., Wang, R.J., Xin, H.B., Zhao, Y.Y., Fan, X.T., 2009. Geochronology and geochemistry of igneous rocks related to the subduction of the Tethys oceanic plate along the Bangong lake arc zone, the western Tibetan Plateau. Geochimica 38, 523–535 (in Chinese with English abstract). Reich, M., Deditius, A., Chryssoulis, S., Li, J.W., Ma, C.Q., Parada, M.A., Barra, F., Mittermayr, F., 2013. Pyrite as a record of hydrothermal fluid evolution in a porphyry copper system: A SIMS/EMPA trace element study. Geochimica et Cosmochimica Acta, 104, 42–62. Rudnick, R., Gao, S., 2003. Composition of the continental crust. Treatise on geochemistry 3, 659. Seal, R.R., 2006. Sulfur isotope geochemistry of sulfide minerals. Reviews in mineralogy and geochemistry 61, 633–677. She, H.Q., Li, J.W., Ma, D.F., Li, G.M., Zhang, D.Q., Feng, C.Y., Qu, W.J., and Pan, G.T., 2009, Molybdenite Re-Os and SHRIMP zircon U-Pb dating of Duobuza porphyry copper deposit in Tibet and its geological implications. Mineral Deposits 28, 737–746 (in Chinese with English abstract). Shentu, B., Wang, Z., 1991. The characteristics and origin type of the Leiwuqi Saibeinong tin deposit, eastern Xizang. Mineralogy and petrology 11, 74–82 (in

Chinese with English abstract). Shi, R.D., Griffin, W.L., O’Reilly, S.Y., Huang, Q.S., Zhang, X.R., Liu, D.L., Zhi, X.C., Xia, Q.X., Ding, L., 2012. Melt/mantle mixing produces podiform chromite deposits in ophiolites: Implications of Re-Os systematics in the Dongqiao Neotethyan ophiolite, northern Tibet. Gondwana Research 21, 194–206. Stein, H.J., Markey, R.J., Morgan, J.W., Hannah, J.L., Scherstén, A., 2001. The remarkable Re-Os chronometer in molybdenite: how and why it works. Terra Nova 13, 479–486. Sun, X., Bi, Z.W., Li, G.D., Zhang, J.Z., Li, Z.M., 2015. Achievements and prospects of regional geological survey in the east Aiyongcuo area, Tibet. Geol. Surv. Chin. 2, 13–18 (in Chinese with English abstract). Takahashi, Y., Uruga, T., Suzuki, K., Tanida, H., Terada, Y., Hattori, K.H., 2007. An atomic level study of rhenium and radiogenic osmium in molybdenite. Geochimica et Cosmochimica Acta 71, 5180–5190. Tang, J.X., Wang, Q., Yang, H.H., Gao, X., Zhang, Z.B., Zhou, B., 2017. Mineralization, exploration and resource potential of porphyry-skarn-epithermal copper polymetallic deposits in Tibet. Acta Geoscientica Sinica 38, 571–613 (in Chinese with English abstract). Tao, Y., Bi, X.W., Li, C.S., Hu, R.Z., Li, Y.B., Liao, M.Y., 2014. Geochronology, petrogenesis and tectonic significance of the Jitang granitic pluton in eastern Tibet, SW China. Lithos 184, 314–323. Tao, Y., Bi, X.W., Xin, Z.L., Zhu, F.L., Liao, M.Y., Li, Y.B., 2011. Geology, geochemistry

and origin of Lanuoma Pb-Zn-Sb deposit in Changdu area, Tibet. Mineral Deposits 30, 599–615 (in Chinese with English abstract). Thode, H.G., Monster, J., Dunford, H.B., 1961. Sulphur isotope geochemistry. Geochimica Et Cosmochimica Acta 25, 159–174. Thomas, H.V., Large, R.R., Bull, S.W., Maslennikov, V., Berry, R.F., Fraser, R., Froud, S., Moye, R., 2011. Pyrite and pyrrhotite textures and composition in sediments, laminated quartz veins, and reefs at Bendigo gold mine, Australia: Insights for ore genesis. Economic Geology 106, 1–31. Wang, B.D., Xu, J.F., Liu, B.M., Chen, J.L., Wang, L.Q., Guo, L., Wang, D.B., Zhang, W.P., 2013. Geochronology and ore-forming geological background of ~90 Ma porphyry copper deposit in the Lhasa Terrane, Tibet Plateau. Acta Geologica Sinica 87, 71–80 (in Chinese with English abstract). Wang, B.D., Wang, L.Q., Chung, S.L., Chen, J.L., Yin, F.G., Liu, H., Li, X.B., Chen, L. K., 2016. Evolution of the Bangong-Nujiang Tethyan ocean: insights from the geochronology and geochemistry of mafic rocks within ophiolites. Lithos 245, 18– 33. Wang, J.P., Zhao, Y.Y., Cui, Y.B., Lü, L.N., Xu, H., 2012. LA-ICPMS zircon U-Pb dating of important skarn type iron (copper) polymetallic deposits in Baingoin County of Tibet and geochemical characteristics of granites: Geological Bulletin of China 31, 1435–1450 (in Chinese with English abstract). Wang, X.Y., Wang, S.F., Wang, C., Tang, W.K., 2018. Permo-Triassic arc-like granitoids along the northern Lancangjiang zone, eastern Tibet: Age,

geochemistry, Sr-Nd-Hf isotopes, and tectonic implications. Lithos 308, 278– 293. Wang, Y.Y., Tang, J.X., Song, Y., Lin, B., Yang, C., Wang, Q., Gao, K., Ding, S., 2017. Geochemical characteristics of sulfur and lead isotopes from the superlarge Tiegelongnan copper (gold-silver) deposit, Tibet. Acta Geoscientica Sinica 38, 627–637 (in Chinese with English abstract). Ward, J., Mavrogenes, J., Murray, A., Holden, P., 2017. Trace element and sulfur isotopic evidence for redox changes during formation of the wallaby gold deposit, western australia. Ore Geology Reviews 82, 31–48. Wilkinson, J.J., 2013. Triggers for the formation of porphyry ore deposits in magmatic arcs. Nature Geoscience 6, 917–925. Wu, D.H., Gao, S.B., Zheng, Y.Y., Tian, K., Zhang, Y.C., Jiang, J.S., Yu, Z.Z., Huang, P.C., 2018. Sulfur and lead isotopic composition and their ore-forming material source of skarn copper polymetallic deposits in southern Tibet BangonghuNujiang metallogenic belt. Journal of Jilin University (Earth Science Edition) 48, 70–86 (in Chinese with English abstract). Xie, G.G., Xie, L., Cao, S.H., Mo, X.X., Dong, G.C., 2009. Prospect evaluation and metallogenic features of the Bangong Lake Fe-Cu polymetallic mineralization belt in western Tibet, China. Geological Bulletin of China 28, 538–545 (in Chinese with English abstract). Xin, H.B., and Qu, X.M., 2006. Geological characteristics and ore-forming epoch of Ri’a copper deposit related to bimodal rock series in Coqen County, western Tibet. Mineral Deposits 25, 477–482 (in Chinese with English abstract).

Xu, W., Li, C., Wang, M., Fan, J.J., Wu, H., Li, X., 2017. Subduction of a spreading ridge within the Bangong Co-Nujiang Tethys Ocean: Evidence from Early Cretaceous mafic dykes in the Duolong porphyry Cu-Au deposit, western Tibet. Gondwana Research 41, 128–141. Yao, X.F., Tang, J.X., Li, Z.J., Deng, S.L., Hu, Z.H., Zhang, Z., 2012. S, Pb isotope characteristics of the Ga'erqiong gold-copper deposit in Tibet: Tracing the source of ore-forming materials. Acta Geoscientica Sinica 33, 528–536 (in Chinese with English abstract). Yang, Y.F., Li, N., Chen, Y.J., 2012. Fluid inclusion study of the Nannihu giant porphyry Mo-W deposit, Henan Province, China: implications for the nature of porphyry ore-fluid systems formed in a continental collision setting. Ore Geology Reviews 46, 83–94. Yin, A., Harrison, T.M., 2000. Geologic evolution of the Himalayan-Tibetan orogen. Annual Review of Earth and Planetary Sciences 28, 211–280. Yong, Y.Y., 2007. Tin and tungsten: potential dominant mineral species in the Gangdise belt, Xizang. Sedimentary Geology and Tethyan Geology 27, 1–8 (in Chinese with English abstract). Yu, H.X., Chen, J.L., Xu, J.F., Wang, B.D., Wu, J.B., Liang, H.Y., 2011. Geochemistry and origin of late cretaceous (~90 Ma) ore-bearing porphyry of Balazha in midnorthern Lhasa terrane, Tibet. Acta Petrologica Sinica 27, 2011–2022 (in Chinese with English abstract). Yu, Y.S., Yang, Z.S., Dai, P.Y., Tian, S.H., Gao, Y., Liu, Y.C., Xiu, D., 2015.

Geochronology and genesis of the magmatism in the Ri’a copper polymetallic deposit of the Nixiong orefield, Coqen, Tibet. Geology in China 42, 118–133 (in Chinese with English abstract). Yu, Y.S., Yang, Z.S., Liu, Y.C., Tian, S.H., Ji, X.H., Gao, Y., Zhao, C., Zhao, W.Q., Liu, A., 2012. Mineralogical characteristics and 40Ar-39Ar dating of phlogopite from the Gunjiu iron deposit in the Nixiong Ore Field, Coqen, Tibet. Acta Petrologica Et Mineralogica 31, 681–690 (in Chinese with English abstract). Yu, Y.S., Yang, Z.S., Tian, S.H., Liu, Y.C., Ji, X.H., Xiu, D., 2013. Metallogenic mechanism of Gunjiu iron deposit in the Nixiong ore-field, Coqen,Tibet: Evidences from mineralogy and stable isotope. Acta Petrologica Sinica 29, 3815–3827 (in Chinese with English abstract). Yuan, H.L., Liu, X., Chen, L., Bao, Z.A., Chen, K.Y., Zong, C.L., Li, X.C., Qiu, J.W., 2018. Simultaneous measurement of sulfur and lead isotopes in sulfides using nanosecond laser ablation coupled with two multi-collector inductively coupled plasma mass spectrometers. Journal of Asian Earth Sciences 154, 386–396. Zartman, R.E., Doe, B. R., 1981. Plumbotectonics—the model. Tectonophysics 75, 135–162. Zhang, H., Liu, H., Liu, S.S., Ma, D.F., Zhang, H., Huang, H.X., Yan, G.Q., 2017. Petrogenesis of the early Cretaceous Jiuqianxi I-type granitic pluton, BangonghuNujiang metallogenic belt, northern Tibet. China Mining Magazine 26, 162–178 (in Chinese with English abstract). Zhang, Q., Pan, J.Y., Shao, S.Y., 2000. An interpretation of ore lead sources from lead

isotopic compositions of some ore deposits in China. Geochimica 29, 231–238 (in Chinese with English abstract). Zhang, X.N., Li, G.M., Qin, K.Z., Lehmann, B., Li, J.X., Zhao, J.X., Cao, M.J., Zou, X.Y., 2018. Petrogenesis and tectonic setting of Early Cretaceous granodioritic porphyry from the giant Rongna porphyry Cu deposit, central Tibet. Journal of Asian Earth Sciences 161, 74–92. Zhang, Z., Fang, X., Tang, J.X., Wang, Q., Yang, C., Wang, Y.Y., Ding, S., Yang, H.H., 2017. Chronology, geochemical characteristics of the Gaerqin porphyry copper deposit in the Duolong ore concentration area in Tibet and discussion about the identification of the lithoscaps and the possible epithermal deposit. Acta Petrol. Sin. 33, 476–494 (in Chinese with English abstract). Zhang, Z., Geng, Q.R., Peng, Z.M., Cong, F., Guan, J.L., 2011. Geochemistry and geochronology of the Caima granites in the western part of the Bangong LakeNujiang metallogenic zone, Xizang. Sedimentary Geology and Tethyan Geology 31, 86–96 (in Chinese with English abstract). Zhang, Z., Yao, X.F., Tang, J.X., Li, Z.J., Wang, L.Q., Yang, Y., Duan, J.L., Song, J.L., and Lin, X., 2015. Lithogeochemical, Re-Os and U-Pb Geochronological, Hf-Lu and S-Pb isotope data of the Ga’erqiong-Galale Cu-Au ore-concentrated area: Evidence for the Late Cretaceous Magmatism and Metallogenic event in the Bangong-Nujiang Suture Zone, Northwestern Tibet, China. Resource Geology 65, 76–102. Zhao, Y.Y., Cui, Y.B., Lü, L.N., Shi, D.H., 2011. Chronology, geochemical

characteristics and the significance of Shesuo copper polymetallic deposit, Tibet. Acta Petrologica Sinica 27, 2132–2142 (in Chinese with English abstract). Zhao, Y.Y., Song, L., Fan, X.T., Shi, D.H., Zhang, T.P., Chen, H.Q., Qu, W.J., 2009. Re-Os dating of molybdenite from the Shesuo copper polymetallic ore in Shenzha county, Tibet and its geological significance. Acta Geologica Sinica 83, 1150–1158 (in Chinese with English abstract). Zheng, Y.Y., Ci, Q., Wu, S., Jin, L.X., Guo, J.C., 2017. The discovery and significance of Rongga porphyry Mo deposit in the Bangong-Nujiang metallogenic belt, Tibet. Earth Science 42, 1441–1453 (in Chinese with English abstract). Zhou, J.X., Dou, S., Huang, Z.L., Cui, Y.L., Ye, L., Li, B., Gan, T., Sun, H.R., 2016. Origin of the Luping Pb deposit in the Beiya area, Yunnan Province, SW China: Constraints from geology, isotope geochemistry and geochronology. Ore Geology Reviews 72, 179–190. Zhou, J.X., Xiang, Z.Z., Zhou, M.F., Feng, Y.X., Luo, K., Huang, Z.L., Wu, T., 2018. The giant Upper Yangtze Pb-Zn province in SW China: Reviews, new advances and a new genetic model. Journal of Asian Earth Sciences 154, 280–315. Zhu, B.Q., 1998. Theories and application of isotopic system in geoscience:crustal and mantle evolution in China continent. Beijing: Science Press, 1–330 (in Chinese). Zhu, D.C., Mo, X.X., Niu, Y.L., Zhao, Z.D., Wang, L.Q., Liu, Y.S., Wu, F.Y., 2009. Geochemical investigation of Early Cretaceous igneous rocks along an east-west traverse throughout the central Lhasa Terrane, Tibet. Chemical Geology 268, 298–312.

Zhu, D.C., Zhao, Z.D., Niu, Y., Dilek, Y., Hou, Z.Q., Mo, X.X., 2013. The origin and preCenozoic evolution of the Tibetan Plateau. Gondwana Research 23, 1429–1454. Zhu, X.P., Li, G.M., Chen, H.A., Ma, D.F., Huang, H.X., 2015. Zircon U-Pb, molybdenite Re-Os and K-feldspar

40Ar/39Ar

dating of the Bolong porphyry Cu-Au deposit,

Tibet, China: Resource Geology 65, 122–135. Zhu, X.P., Li, G.M., Chen, H.A., Ma, D.F., Zhang, H., Zhang, H., Liu, C.Q., Wei, L.J., 2017. Petrogenesis and metallogenic setting of porphyries of the Duobuza porphyry Cu-Au deposit, central Tibet, China. Ore Geology Reviews 89, 858– 875. Zindler, A., Hart, S., 1986. Chemical geodynamics. Annual Review of Earth and Planetary Sciences 14, 493–571.

Figure and table captions Figure 1. (A) Tectonic subdivision of the Tibetan Plateau-Sanjiang Region (modified after Metcalfe, 2013); (B) Simplified geological map and the distribution of mineral deposits in the Bangong-Nujiang belt (after Yin and Harrison, 2000; Hou et al., 2007; Cao et al., 2017; Li et al., 2018a). See Table 1 and the text for data sources and discussion.

Figure 2. Geological map of the Leiwuqi-Zogang belt in eastern Tibet.

Figure 3. (A) Geological map of the Larong W-Mo deposit and (B) cross-section map

for a-b. Labels: 1 - Quaternary; 2 - Proterozoic Youxi Group; 3 - Lower Carboniferous Kagong Formation; 4 - quartz schist; 5 - hornstone; 6 - granodiorite porphyry; 7 monzogranite porphyry; 8 - granodiorite dike; 9 - granite dike; 10 - granite aplite dike; 11 - skarn; 12 - limestone; 13 - fault; 14 - ore body; 15 - potassic zone; 16 - strongly quartz-sericite (muscovite) zone; 17 - weakly quartz-sericite ± chlorite zone; 18 - drill hole; 19 - cross-section.

Figure 4. Photographs of typical alteration characteristics of the Larong W-Mo deposit. (A) Limonitization in the surface of the mining area; (B) hornstone in the porphyry contact zone; (C) sericitization, silicification, pyritization and weak chloritization in granodiorite porphyry; (D) greisenization and local fluoritization in granodiorite porphyry; (E) potassic alteration (microclinization) in monzogranite porphyry; (F) weak potassic alteration in porphyritic monzonite granite; (G) skarnization in quartz-mica schist; (H) sericitization and silicification in granodiorite porphyry (cross-polarized light); (I) muscovitization and carbonatization in granodiorite porphyry (cross-polarized light); (J) chloritization in granodiorite porphyry (plane-polarized light); (K) chlorite–epidote skarn (plane-polarized light); (L) epidote skarn (cross-polarized light).

Figure 5. Characteristics of the ore compositions, textures and structures in the Larong W-Mo deposit. (A) Veinlet-disseminated scheelite in granodiorite porphyry; (B) same sample of figure 5A under fluorescent lamp; (C) early quartz + scheelite vein cut by late quartz + molybdenite veins; (D) disseminated, vein-type molybdenite and pyrite in

altered granodiorite porphyry; (E) molybdenite vein distributed along quartz vein wall; (F) veinlet-disseminated molybdenite and pyrite in monzogranite porphyry; (G) hypidiomorphic granular scheelite; (H) scheelite replaced by molybdenite and coexisting with chalcopyrite; (I) molybdenite replacing scheelite; (J) molybdenite with deflection structure; (K) molybdenite replacing pyrite; (L) xenomorphic granular chalcopyrite. Abbreviations: Ccp - chalcopyrite; Mo - molybdenite; Py - pyrite; Qtz quartz; Sch - scheelite.

Figure 6. Representative SEM photomicrographs showing δ34S‰ values for sulfides. Note: The red line represents the analyzed spot for in-situ S isotope; blue line represents in-situ Pb isotope analytical spot. Abbreviations are the same as in Fig. 5.

Figure 7. Paragenetic sequence for the Larong W-Mo deposit.

Figure 8. Upper crust-normalized trace element variation diagram of sulfides. Upper crust value is from Gao et al., 1998.

Figure 9. Representative time-resolved LA-ICPMS spectras for selected elements in (A) pyrite, (B) molybdenite and (C) chalcopyrite.

Figure 10. (A-C) Frequency histogram of δ34SVCDT values and (D) range of δ34SVCDT values for metal sulfides from the typical deposits in the Bangong-Nujiang belt. Data

for Cu-Au deposits are from Zhao et al. (2011), Yao et al. (2012), Bai et al. (2015), Zhang et al. (2015), Li et al. (2017b, 2018b), Lin et al. (2017), Lv et al. (2011), Wang et al. (2017); Data for Fe-Cu deposits are from Yu et al. (2011), Wu et al. (2018); Data for W-Mo deposit are from this study.

Figure 11. The δ34SVCDT values of pyrites from the Larong deposit.

Figure 12. (A) Plot of 207Pb/204Pb versus 206Pb/204Pb (Modified from Zartman and Doe et al., 1981; Zindle and Hart, 1986; Miller et al., 1999) and (B) Δβ versus Δγ diagram (Modified from Zhu et al., 1998) of metal sulfides from the typical deposits in the Bangong-Nujiang belt. Data sources are the same as in Fig. 10.

Figure 13. Histogram showing the number of deposits in the Bangong-Nujiang metallogenic belt. See Table 1 and the text for data sources and discussion.

Table 1: Summary of characteristics for major ore deposits in the Bangong-Nujiang metallogenic belt.

Table 2: Sulfur isotopic compositions of sulfides from the Larong deposit.

Table 3: Pb isotopic ratios of molybdenite from the Larong deposit.

Supplementary Table 1: LA-ICPMS data of sulfides from the Larong deposit.

Graphical abstract

Highlights

1. Sulfur of the Larong W-Mo deposit is of magmatic origin. 2. In-situ trace elemental and Pb isotopic compositions indicate that the ore-forming materials were mainly derived from the crust. 3. Intense fluid-rock interaction inducing gradual decreasing of oxygen fugacity and temperature might be the key factor resulting in the successive mineralization of W and Mo. 4. Three W-dominated polymetallic metallogenic events and mineralization potential of igneous rocks have been identified in the Bangong-Nujiang metallogenic belt.

Table 1

Summary of characteristics for major ore deposits in the Bangong-Nujiang metallogenic belt. Deposit

Metals

Type

1. Songmo

W

Granite-related

–

Granite

160~168

2. Aiyongco

Fe

Skarn

–

Biotite monzogranite

160~165

3. Caima

Fe

Skarn

Small

4. Ga’erqiong

Cu, Au, Fe

Skarn

Large

5. Galale

Cu, Au, Fe

Skarn

Large

Granodiorite

86.5~88.3

6. Shilong

W

Granite-related

–

Biotite monzogranite

113.5 ± 0.6

7. Shilong

Fe

Skarn

–

Biotite monzogranite

113.5 ± 0.6

8. Bagong

Cu, Pb, Zn, Ag

Hydrothermal vein

–

Quartz drorite

113~115

9. Fuye

Fe, Cu, Au, Ag

Skarn

Small

Granite porphyry

119.1~157.4

10. Rongga

Mo

Porphyry

Large

Monzogranite porphyry

–

11. Purang

Fe

Skarn

–

Quartz monzonite

116 ± 2.0

12. Qingcaoshan

Cu, Au

Porphyry

Large

Granodiorite porphyry

114.6~115.8

13. Xianqian

Fe

Skarn

–

Granodiorite

159.3 ± 3.3

14. Jiuqianxi

Fe, Cu, Pb, Ag

Skarn

–

Quartz monzonite

120 ± 1.0

15. Lemachaha

Pb, Zn, Cu

Hydrothermal vein

–

Granodiorite

159.3 ± 3.3

16. Bainong

Cu, Au

Porphyry

Small

Diorite porphyrite

115 ± 1.1

17. Dibaonamugang

Cu, Au

Porphyry

Large

Drorite, Quartz drorite

122 ± 2.5

18. Nadun

Cu, Au

Porphyry-epithermal

Small

Granodiorite porphyry

119.1 ± 1.3

19. Bolong

Cu, Au

Porphyry

Large

Granodiorite porphyry

118.5~121.1

20. Duobuza

Cu, Au

Porphyry

Large

Granodiorite porphyry

116.8~120.9

21. Rongna

Cu, Au, Ag

Porphyry-epithermal

Giant

Granodiorite porphyry

120.2 ± 1.0

22. Naruo

Cu, Au

Porphyry

Large

Granodiorite porphyry

120~126.2

23. Sena

Cu, Au

Porphyry

Large

Quartz diorite porphyrite

122 ± 1.8

24. Tiegelong

Cu, Au

Porphyry

Small

Quartz diorite

122.1 ± 0.7

25. Gaerqin

Cu, Au

Porphyry

Large

Granodiorite porphyry

124.4 ± 0.4

26. Tiegeshan

Au

Quartz vein

Small

Granodiorite

119.3~123 ***

scale

Associated magmatic rocks

Age of magmatism

Deposit

Biotite monzogranite, granodionite Granodiorite, diorite porphyrite

(Ma)

159.8~165.1

87.1~91.7

m

27. Tiangongnile

Cu-Au

Skarn

Middle

Granodiorite

102.6 ± 1.8

28. Dacha

Au

Quartz vein

Middle

Andesite porphyry

104.9~103.2 ***

29. Sebuta

Cu, Mo

Porphyry

Small

30. Balazha

Cu, Mo

Porphyry-skarn

Middle

31. Nixiong

Fe, Cu

Skarn

Large

Granodiorite, monzogranite

112.6~113.6

32. Ri’a

Cu

Skarn

Middle

Biotite granite

89.9~90.1

33. Shesuo

Cu

Skarn

Small

Granodiorite

116.2 ± 0.9

34. Xiongmei

Cu, Au

Porphyry

Small

Granodioritic porphry

106.1 ± 0.5

35. Xueru

Fe, Cu

Skarn

Small

monzogranite

79.7~76.1

36. Zai’a

Fe, Bi, Cu

Skarn

Small

Porphyritic granodiorite

77.4~79.8

37. Gengnai

Fe, In

Skarn

Small

monzogranite

78.7 ± 1.7

38. Qiboxiari

Sn

Greisen

Small

Biotite granite

98.2 ****

39. Laqing

Cu, Fe

Skarn

Middle

Monzogranite

114.2 ± 0.9

40. Dongqiao

Cr

Magmatic segregation

Middle

Gabbro

187.8 ± 3.7

41. Zhagela

Au

Hydrothermal vein

Middle

Granite porphyry

Late Cretaceous

42. Saibeinong

Sn

Hydrothermal vein

Small

Granodiorite porphyry

99.2~74.9 ***

43. Dongpulu

Cu, W, Sn

Hydrothermal vein

Middle

Monzonitic granite

76.9~78.3

44. Larong

W, Mo

Porphyry

Large

Monzonitic granite porphyry

93.9 ± 1.3

Biotite granite,

–

granitic porphyry Monzogranite,

88~93.8

granitic porphyry

* means magmatism or mineralization ages were determined by molybdenite Re-Os, ** by phlogopite/sericite 40Ar/39Ar,

U-Pb.

*** by whole-rock/feldspar K-Ar, **** by whole-rock/sphalerite Rb-Sr, others by zircon LA-ICP-MS/SHRIMP

Table 2 Sulfur isotopic compositions for sulfides from the Larong deposit. Stage

Stage II-1

Sample no.

LR-ZK0401-193-1

LR-ZK0703-285

LR-ZK0303-289

Description

Scheelite-molybdenite-chalcoprite-pyrite vein

Disseminated sulfides in skarn

LR-ZK0803-414

Stage II-3

LR-ZK0803-384

δ34SVCDT(‰)

2σ

Chalcoprite

0.46

0.18

Molybdenite

2.50

0.16

Pyrite

0.47

0.16

Molybdenite

2.44

0.18

Pyrite

0.25

0.15

Molybdenite

2.31

0.18

Pyrite

0.28

0.15

Molybdenite

2.68

0.17

Molybdenite

2.11

0.17

Pyrite

2.11

0.17

Pyrite

2.26

0.15

Pyrite

2.09

0.16

Pyrite

2.38

0.17

Pyrite

0.72

0.17

Pyrite

2.50

0.16

Pyrite

1.87

0.16

Molybdenite

1.99

0.26

Pyrite

0.87

0.14

Molybdenite

2.19

0.17

Pyrite

2.14

0.16

Molybdenite

1.74

0.16

Pyrite

1.85

0.17

Molybdenite

2.35

0.16

Pyrite

0.87

0.15

Pyrite

2.16

0.16

Pyrite

2.36

0.17

Molybdenite

2.14

0.18

Pyrite

6.37

0.15

Molybdenite

1.77

0.29

Pyrite

5.13

0.16

Molybdenite

2.35

0.21

Pyrite

4.52

0.16

Pyrite

2.63

0.17

Scheelite-pyrite vein

Stage II-2

LR-ZK0401-318

Mineral

Molybdenite-pyrite vein

Disseminated pyrite in monzogranite porphyry

Scattered pyrite and molybdenite vein

Table 3 Lead isotopic ratios for molybdenite from the Larong deposit. Sample no.

208

Pb/

204

Pb

2σ

207

204

Pb/

Pb

2σ

206

204

Pb/

Pb

2σ

μ

ω

Th/U

△α

△β

△γ

LR-ZK0401-318-1mo

39.370

0.008

15.799

0.003

18.849

0.003 9.81 39.76 3.92 93.14 30.69 54.73

LR-ZK0401-318-2mo

39.361

0.016

15.798

0.006

18.843

0.007 9.81 39.75 3.92 92.77 30.64 54.47

LR-ZK0401-318-3mo

39.588

0.050

15.879

0.018

18.942

0.019 9.96 40.90 3.97 98.53 35.95 60.57

LR-ZK0401-318-4mo

39.586

0.060

15.867

0.021

18.991

0.022 9.93 40.49 3.95 101.39 35.11 60.52

LR-ZK0401-193-1mo

39.448

0.029

15.809

0.012

18.955

0.014 9.82 39.58 3.90 99.29 31.37 56.82

LR-ZK0401-193-2mo

39.899

0.071

15.893

0.029

19.451

0.035 9.94 39.46 3.84 128.02 36.85 68.91

LR-ZK0401-193-3mo

39.908

0.093

15.928

0.037

19.386

0.046 10.01 40.17 3.88 124.26 39.13 69.13

LR-ZK0401-193-4mo

39.592

0.074

15.822

0.030

19.142

0.036 9.83 39.25 3.86 110.10 32.22 60.68

LR-ZK0401-193-5mo

39.711

0.055

15.852

0.022

19.267

0.026 9.87 39.32 3.86 117.35 34.17 63.86

LR-ZK0401-193-6mo

39.586

0.120

15.747

0.047

19.432

0.058 9.66 37.02 3.71 126.92 27.32 60.52

LR-ZK0401-193-7mo

39.764

0.141

15.806

0.055

19.644

0.069 9.76 37.16 3.68 139.26 31.19 65.29

LR-ZK0401-193-8mo

39.644

0.051

15.835

0.020

19.209

0.024 9.85 39.21 3.85 113.98 33.03 62.06

LR-ZK0401-193-9mo

39.695

0.031

15.855

0.012

19.986

0.017 9.84 35.74 3.52 159.09 34.39 63.44

LR-ZK0401-193-10mo

39.717

0.020

15.865

0.008

19.991

0.012 9.85 35.88 3.53 159.37 35.03 64.02

LR-ZK0401-193-11mo

39.729

0.035

15.857

0.013

20.120

0.017 9.83 35.26 3.47 166.82 34.47 64.35

LR-ZK0401-282-1mo

39.650

0.132

15.877

0.053

19.258

0.065 9.92 39.38 3.84 116.84 35.82 62.23

LR-ZK0401-282-2mo

39.356

0.208

15.760

0.078

19.182

0.097 9.70 37.54 3.75 112.46 28.14 54.36

LR-ZK0401-282-3mo

39.480

0.073

15.807

0.029

19.194

0.036 9.79 38.39 3.80 113.15 31.23 57.67

Authors’ contributions: 1) Wenchang Li, Xiangping Zhu and Jun Liu conceived and designed the study; 2) Jun Liu performed the experiments and wrote the paper; 3) Wenchang Li, Xiangping Zhu, Jia-Xi Zhou and Haijun Yu reviewed and edited the manuscript; 4) All authors read and approved the manuscript.