(A) Simplified geological map showing major tectonic units of China. (B) Regional geological map of the Anwangshan gold deposit. 1 = Anwangshan, 2 = Pangjiahe, 3 = Matigou.

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Context 1

... Qinling Orogen is a unique continental composite orogenic belt spanning the central part of China ( Figure 1A). Since the break-up of the Rodinia supercontinent in the Neoproterozoic, the Qinling Orogen has undergone multiple tectonic evolutionary stages, including the formation of the Qin-Qi-Kun Ocean, oceanic crustal subduction orogeny, continental collision orogeny, intraplate extension, and intracontinental superimposed orogeny [1,[27][28][29]. ...

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... research area is situated at the northwest part of the Fengtai basin in the WQO, which is famous for its numerous Pb-Zn and gold deposits [33,34]. The outcropped strata covered a wide time span from the Early Proterozoic to the Carboniferous ( Figure 1B) [35]. This includes the Paleoproterozoic Qinling Group (Pt 1 Q), which is in fault contact with the Lower Paleozoic Danfeng Group (Pz 1 D) to the south and the Ordovician Longwanggou Formation (Ol) to the north, consisting mainly of gneiss, amphibolite, granulite, and marble [36]. ...

Context 3

... Carboniferous Caoliangyi Formation (Cc) is in fault contact with the Ozh in the south and is intruded by the Baoji batholith in the north. It is mainly composed of quartz sandstone, quartz conglomerate, etc. ( Figure 1B). The research area is situated at the northwest part of the Fengtai basin in the WQO, which is famous for its numerous Pb-Zn and gold deposits [33,34]. ...

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... research area is situated at the northwest part of the Fengtai basin in the WQO, which is famous for its numerous Pb-Zn and gold deposits [33,34]. The outcropped strata covered a wide time span from the Early Proterozoic to the Carboniferous ( Figure 1B) [35]. This includes the Paleoproterozoic Qinling Group (Pt1Q), which is in fault contact with the Lower Paleozoic Danfeng Group (Pz1D) to the south and the Ordovician Longwanggou Formation (Ol) to the north, consisting mainly of gneiss, amphibolite, granulite, and marble [36]. ...

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... Carboniferous Caoliangyi Formation (Cc) is in fault contact with the Ozh in the south and is intruded by the Baoji batholith in the north. It is mainly composed of quartz sandstone, quartz conglomerate, etc. ( Figure 1B). ...

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... the compression of north-south stress in the late Caledonian, nearly east-west-to northwest-oriented faults were formed, represented by the Miaoping-Kangjialiang fault and Multiple stages and types of fault are well-developed in the research area [38]. Under the compression of north-south stress in the late Caledonian, nearly east-west-to northwestoriented faults were formed, represented by the Miaoping-Kangjialiang fault and the Majiayao-Baijiadian ductile-brittle fault which are distributed in the central part of the region ( Figure 1B). The east-west Luohansi-Wayaoshang ductile-brittle fault was formed during the Indosinian period. ...

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... ε Hf (t) values of quartz syenite range from −6.68 to +2.25, slightly lower than those of the diopside-bearing syenite in Jiuzigou, and much lower than the depleted mantle values during the same period (Figure 10). When the ε Hf (t) of zircon is negative, it is generally believed that magma originated from the crust or enriched mantle, or resulted from crustal mantle mixing. ...

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... the lg [CaO/(Na 2 O + K 2 O)] − SiO 2 diagram indicates that the 231 Ma quartz syenite should form in an extensional background ( Figure 11A). The enrichment of Th, Rb, Ba, and LREE and the negative anomalies of Ta, Nb, and Ti ("TNT" deficiency) also indicate that the source mantle has already been metamorphized by the melt generated by subducting plates [55,77]. ...

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... enrichment of Th, Rb, Ba, and LREE and the negative anomalies of Ta, Nb, and Ti ("TNT" deficiency) also indicate that the source mantle has already been metamorphized by the melt generated by subducting plates [55,77]. The w (Rb) − w (Nb + Y) diagrams show that the quartz syenite has a strong post-collisional affiliation ( Figure 11B). If the early Indosinian magmatic activity (245-235 Ma) is still under an active continental margin environment [12,13], there will not be enough time to finish the subsequent continental collision and transform the stress environment from compression to extension. ...

Context 10

... is not easy to deny that the two simultaneous syenite-ultramafic complexes should generate from the same source region. Moreover, the lg [CaO/ (Na2O + K2O)] − SiO2 diagram indicates that the 231 Ma quartz syenite should form in an extensional background ( Figure 11A). The enrichment of Th, Rb, Ba, and LREE and the negative anomalies of Ta, Nb, and Ti ("TNT" deficiency) also indicate that the source mantle has already been metamorphized by the melt generated by subducting plates [55,77]. ...

Context 11

... enrichment of Th, Rb, Ba, and LREE and the negative anomalies of Ta, Nb, and Ti ("TNT" deficiency) also indicate that the source mantle has already been metamorphized by the melt generated by subducting plates [55,77]. The w (Rb) − w (Nb + Y) diagrams show that the quartz syenite has a strong post-collisional affiliation ( Figure 11B). If the early Indosinian magmatic activity (245-235 Ma) is still under an active continental margin environment [12,13], there will not be enough time to finish the subsequent continental collision and transform the stress environment from compression to extension. ...

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... Diagrams of initial εHf values versus the U-Pb ages of zircon from the quartz syeni and Jiuzigou complex. (B) Enlarged data display of Figure 11A. Data for Jiuzigou complex are from Gong [54]. ...

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... the lg [CaO/ (Na2O + K2O)] − SiO2 diagram indicates that the 231 Ma quart syenite should form in an extensional background ( Figure 11A). The enrichment of Th Rb, Ba, and LREE and the negative anomalies of Ta, Nb, and Ti ("TNT" deficiency) als indicate that the source mantle has already been metamorphized by the melt generate by subducting plates [55,77]. ...

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... enrichment of Th Rb, Ba, and LREE and the negative anomalies of Ta, Nb, and Ti ("TNT" deficiency) als indicate that the source mantle has already been metamorphized by the melt generate by subducting plates [55,77]. The w (Rb) − w (Nb + Y) diagrams show that the quart syenite has a strong post-collisional affiliation ( Figure 11B). If the early Indosinian mag matic activity (245-235 Ma) is still under an active continental margin environmen [12,13], there will not be enough time to finish the subsequent continental collision an transform the stress environment from compression to extension. ...

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... quartz syenite veins in the Anwangshan gold deposit have an average gold content of 12.8 ppb [41]. The sulfur isotope composition of Py1 (−1.1‰ to +3.8‰) shows clear mantle sulfur affiliation, which is significantly different from orogenic gold deposits related to regional metamorphism in the WQO (Figure 12). Thus, the quartz syenite could provide part of the gold source during the first mineralization stage. ...

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... the quartz syenite could provide part of the gold source during the first mineralization stage. During stage II, the sulfur isotope composition of Py2 ranges between Py1 and the majority of orogenic gold deposits (deep gray) in the WQO (Figure 12). This indicates that metamorphic gold may join in during the late gold mineralization stage in the Anwangshan gold deposit. ...

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... quartz syenite veins in the Anwangshan gold deposit have an average gold content of 12.8 ppb [41]. The sulfur isotope composition of Py1 (−1.1‰ to +3.8‰) shows clear mantle sulfur affiliation, which is significantly different from orogenic gold deposits related to regional metamorphism in the WQO (Figure 12). Thus, the quartz syenite could provide part of the gold source during the first mineralization stage. ...

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... the quartz syenite could provide part of the gold source during the first mineralization stage. During stage II, the sulfur isotope composition of Py2 ranges between Py1 and the majority of orogenic gold deposits (deep gray) in the WQO (Figure 12). This indicates that metamorphic gold may join in during the late gold mineralization stage in the Anwangshan gold deposit. ...

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... indicates that metamorphic gold may join in during the late gold mineralization stage in the Anwangshan gold deposit. Figure 12. Comparison of sulfur isotopes between the Anwangshan gold deposit and the typical orogenic gold deposits in the WQO. ...

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... Ma), but a totally different metal and fluid source in stage I. The mixing of magmatic fluids with metamorphic fluids led to stage II sulfur isotope compositions and ore-forming fluid temperatures similar to those of orogenic gold deposits ( Figures 9A and 12). ...