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In South China, extensive multi-phase magmatism was accompanied by W-dominated, polymetallic mineralization. The Xingguo orefield of southern Jiangxi Province in the eastern part of the Nanling region is one of the most important W-dominated mineralized regions in South China. There are more than ten W deposits within or surrounding the Jiangbei complex, including the Huamei’ao quartz vein-type W deposit (WO 3 67,400 tons at a grade of 1.344%), the Yanqian skarn-type W deposit (WO 3 16,000 tons at a grade of 0.365%), and the Zhangjiadi quartz-vein- and greisen-type Mo-W deposit (Mo 31,806 tons at a grade of 0.1% and WO 3 1746 tons at a grade of 0.353%). The orebodies all occur at the contact between the Jiangbei complex and the Sinian metasandstone or Carboniferous-Permian limestone. The Jiangbei complex consists of three lithologies: medium- to coarse-grained, biotite granite (Jγ 1 ), medium- to fine-grained, biotite monzonitic granite (Jγ 2 ), and fine-grained, biotite monzonitic granite (Jγ 3 ), which have zircon U-Pb ages of 160.7 ± 1.1 Ma, 156.3 ± 0.9 Ma, and 153.3 ± 0.8 Ma, respectively. The associated Yanqian, Huamei’ao, Wangnipai, and Liujiazhuang deposits have molybdenite Re-Os ages of 159.2 ± 2.3 Ma, 157.1 ± 1.3 Ma, 157.7 ± 1.4 Ma, and 157.9 ± 1.6 Ma, respectively. A summary of available age dates of intrusions in the Xingguo orefield indicates that the granitic magmatism lasted for ∼8 m.y (ca. 160–153 Ma), whereas the W mineralization occurred in a relatively short period (159–155 Ma), corresponding in age to the episode of large-scale, Mesozoic (165–150 Ma) mineralization in South China. Low εNd(t) values (−10.2–−13.0) of the Jiangbei granitic rocks and low Re contents of the molybdenite suggest that the W-dominated ores and associated granites in the Xingguo orefield were derived mainly from crustal magmas. All three lithologies of the Jiangbei complex have similar geochemical characteristics, and are classified as high-K, calc-alkaline and peraluminous, S-type granites. The Zr/Hf, Nb/Ta, δEu, Rb/Sr, and LREE/HREE ratios all correlate positively with the W contents of the rocks and reach their highest level in the phase II granites. We propose a magmatic-metallogenic model in which W was concentrated by fractionation of crustally derived magmas of phase I and then deposited in skarn-, greisen-, and quartz vein-type ores by both magmatic and hydrothermal processes. [ABSTRACT FROM AUTHOR]

[Display omitted] • SIMS U-Pb dating of Jiama intrusives brackets magmatic event related to Jiama porphyry-skarn mineralization in 1.3 Myr. • Zircon O-Hf isotopic compositions suggest Jiama ore-forming magmas were derived from melting of the newly formed Tibetan lower crust. • No significant magma mixing has been observed during the magmatic evolution from diorite to granite. The post-collisional Gangdese metallogenic belt with over 45 Mt Cu has attracted worldwide attention. We report the whole-rock geochemistry, zircon SIMS U–Pb geochronology, and in situ zircon Hf–O isotopic compositions of the Jiama deposit in the Gangdese belt. The intermediate to the felsic intrusive rocks are characterized by high SiO 2 (64.8 to 78.8 wt. %) and Al 2 O 3 (12.1 to 16.3 wt. %) contents, high Sr/Y ratios (43–74), showing the geochemical characteristics of adakites. Zircons from four intrusives yield U–Pb ages of 16.19 ± 0.20 Ma, 15.67 ± 0.32 Ma, 15.44 ± 0.16 Ma, and 14.90 ± 0.16 Ma, respectively, which brackets magmatic event related to mineralization in 1.3 Myr (16.19 to 14.90 Ma). Magmatic zircons have intermediate δ18O (+5.21 to + 7.18‰), and depleted Hf isotopic values (εHf(t) = 1.8 to 9.4). In combination of whole rock, plagioclase, and zircon geochemistry, we suggest the main ore-forming magma was derived from the remelting of the newly formed lower crust. During the whole journey of magma ascending from lower crust to the surface, no significant injection or mixing of mafic melt from different source has been observed. This is supported by three lines of evidence: 1) There is no clear reverse zonation in plagioclase, 2) the major and trace element compositions of continuous lithologies from diorite to granite shows no significant mixing, 3) there is no significant change of the zircon O and Hf isotope among different intrusions. Our study suggests that the formation of the giant porphyry deposits such as Jiama in post-collisional setting likely form in a short-term (<1.5 Myr) without significant magma mixing during magmatic evolution from diorite to granite. [ABSTRACT FROM AUTHOR]