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The recently discovered giant Huoshaoyun zinc-lead deposit in the Karakorum Range, northwestern Tibet, China, consists of a major zinc-lead carbonate and a minor lead-dominant sulfide mineralization with metal reserves of zinc and lead of over 16 million tonnes. The zinc-lead carbonate mineralization is composed of smithsonite and cerussite, with laminated, massive, veined and botryoidal textures, showing sedimentary and metasomatic structures. The lead-dominant sulfide mineralization is composed mainly of galena and minor sphalerite and pyrite, with laminated, brecciated, and veined textures. The laminated sulfide mineralized zones occur at the top of the deposit, whereas the zinc-lead carbonate mineralized bodies are located below the sulfide zones. Lead-dominant sulfide veins cut the zinc-lead carbonate ores and the host limestone. The sequence of formation of the lead-zinc ores with various mineral colors in thin sections is as follows: (1) light-colored to yellowish, fine- to coarse- and subhedral to euhedral smithsonite; (2) yellowish to reddish, fine- to coarse- and subhedral to euhedral smithsonite; (3) light-colored veined smithsonite; (4) white coarse-grained, xenomorphic cerussite; (5) colorless euhedral to sub-angular quartz crystals; (6) euhedral to anhedral lead-zinc sulfides and gypsum. The mineralization events of the Huoshaoyun deposit are: (1) early hydrothermal sedimentary smithsonite mineralization; (2) hydrothermal replacive smithsonite mineralization; (3) vein-type smithsonite mineralization; (4) open space filling and replacive cerussite mineralization; (5) lead-zinc sulfide mineralization. The fluid inclusions of cerussite indicate that the hydrothermal fluids of the cerussite ore-forming stage are characterized by a temperature range of at least 186–206 °C and low salinities (0.7–1.2 wt% NaCl eq.). The source of oxygen and carbon for the zinc-lead carbonate mineralization is possibly consistent with the involvement of marine water and a magmatic fluid, and is probably dominated by the magmatic fluid. The source of sulfur for the lead-dominant sulfide mineralization is possibly related to a magma reservoir. The zinc-lead-carbonate portion of the deposit represents a primary hypogene non-sulfide mineralization.

The Kaladawan Fe–Mo ore field (Altyn, Xinjiang) in Northwest (NW) China contains six deposits, with a total reserve of 60 Mt Fe and 10 Kt Mo metal. The orebodies are hosted in lower Paleozoic andesite, dacite, phyllite and marble with well-developed skarn alteration. The Kaladawan granites are newly U–Pb dated to be Early Ordovician (476.1 ± 3.3 Ma), largely coeval with the Fe–Mo mineralization (molybdenite Re–Os: 480.3 ± 3.2 Ma). The granites contain high SiO 2 , K 2 O and Al 2 O 3 , low TiO 2 , MgO and CaO, with high K 2 O/Na 2 O ratios (1.26–1.58) and A/CNK values (1.00–1.08), showing peraluminous high-K calc-alkaline affinity. The rocks are characterized by large ion lithophile element (LILE) and light rare earth element (LREE) enrichments and depletions of Sr, Ba, Nb, Ta, Ti and P, and with negative Eu anomalies. The rocks have initial 87 Sr/ 86 Sr ratios of 0.7066 to 0.7112 and e Nd ( t ) values of −1.4 to −1.1, with T DM2 (Nd) ages of 1.32–1.30 Ga. Zircon e Hf (t) values range from 2.9 to 6.4, with T DM2 (Hf) ages of 1.26–1.04 Ga. The new geochemical and isotopic data suggest that the Kaladawan granites are highly fractionated I-type, and likely formed by fractional crystallization of a magma that was derived from partial melting of a mixture of crustal and mantle materials. Deposits in the Kaladawan Fe–Mo field are skarn-type and may have occurred in an active continental margin, via the contact metamorphism and metasomatic reaction between granite-derived fluids and the wall rocks.

The Kaladawan Fe–Mo ore field in Altyn (Xinjiang Province, NW China) contains six Fe (–Mo) deposits, with total proven reserves of 60 Mt Fe and 10,000 t Mo. Tabular, lensoidal and stratiform orebodies occur in the Cambrian foliated marble, phyllite, carbonaceous slate, chlorite–sericite schist and quartz–sericite schist along the exocontact zone of the Kaladawan granite. Skarns are extensively developed and dominated by garnet, pyroxene, epidote, tremolite and actinolite, with minor chlorite, zoisite, quartz and calcite. Ore minerals are mainly magnetite and molybdenite. Five alteration and mineralization stages (I–V) were identified: the prograde (I) and retrograde (II) skarns are characterized by assemblages of garnet–pyroxene and epidote–tremolite–actinolite, respectively, intruded and replaced by mineral assemblages of magnetite–epidote–zoisite (III), quartz–sulfides (IV) and calcite–chlorite (V) in younging order. The Kaladawan garnet contains more andradite (61.2–94.4 mol%) than grossularite (37.5–5.0 mol%). Pyroxene is Mg-rich and Fe-poor, with an endmember range of 55.4–94.7 mol% diopside and 42.5–4.7 mol% hedenbergite. Amphibole comprises mainly tremolite and actinolite. The Kaladawan skarn mineral contents resemble typical skarn Fe and Mo deposits. In-situ LA-ICP-MS magnetite trace element analysis had identified unusually high Mg, Mo and Cr concentrations. The high Mo and the absence of molybdenite inclusions in magnetite suggest that the hydrothermal fluids may have been Mo-rich. The magnetite also contains similar (Ti + V) and (Al + Mn) values with typical skarn Fe deposits. Therefore, the Kaladawan Fe–Mo mineralization is best attributed to be skarn-type, and related to the Kaladawan granite intrusion.

The Xiaobaishitou W (–Mo) deposit is located in the eastern segment of the Central Tianshan, northwestern China. The deposit represents a skarn system distributed in the contact zones of biotite granite and crystalline limestone of the Mesoproterozoic Kawabulag Group. The Xiaobaishitou deposit is characterized by a typical calc-silicate mineralogy dominated by garnet, diopside and wollastonite, with minor epidote, tremolite, actinolite, chlorite, quartz, fluorite and calcite. The prograde and retrograde skarns are characterized by garnet–clinopyroxene–wollastonite and epidote–tremolite–actinolite–chlorite, respectively, intruded and replaced by mineral assemblages of scheelite–cassiterite–magnetite, quartz–sulfides and calcite–quartz–fluorite in younger order. Six molybdenite samples from the deposit yielded Re − Os isotope model ages ranging from 239.7 ± 3.6 Ma to 251.4 ± 3.6 Ma. The zircon crystals from biotite granite and Mo-mineralized granite yield weighted 206Pb/238U age of 242 ± 1.7 and 240.5 ± 2.1 Ma, respectively. Both the zircon U − Pb and the molybdenite Re − Os ages obtained in this study fall in a narrow span of 242–240 Ma, which suggest that the Xiaobaishitou W (–Mo) system was formed in the Triassic. The Re contents of the molybdenites range from 40.33 to 64.67 ppm, suggesting that the ore-forming materials were derived mainly from continental crust together with the involvement of minor mantle components. Combined with the 87Sr/86Sr ratios of tungsten-bearing quartz veins from other studies, which scatter between 0.707153 and 0.709877, demonstrating mixing between two end-member isotopic compositions of crust and mantle. It can be concluded that the Indosinian Xiaobaishitou deposit was formed in a tectonic transition from collisional crust shortening and thickening to post-collisional extension and thinning.

Tourmaline is widespread in the Baiganhu W–Sn deposit, Xinjiang Province, NW China. In this study, electron microprobe analysis reveals that tourmaline in the Baiganhu deposit belongs to the alkali and X-site group with low Ca and moderate X site vacancy, all beyond the confines of schorl–dravite series, with Na/(Na + Ca) and Fe/(Fe + Mg) ratios ranging from 0.769 to 0.965 and 0.518 to 0.822, respectively. In chemical discrimination diagrams, the tourmaline samples plot in the fields of Li-poor granite, associated with Al-saturated metapelites and metapsammites. The tourmaline cores are depleted in Mg, Ca, Ti, but enriched in Al and Fe compared to the rims. Substitution mechanisms for the compositional variations are dominantly due to MgFe− 1, □Al(NaFe)− 1, □Al(NaMg)− 1, and AlO(Fe− 1(OH))− 1 exchange vectors. The δ11B values of the tourmalines range from − 12.9 to − 7.9‰, with a slight variation between cores and rims, which reflect a common boron source, and also indicate that the tourmaline crystallized during a single magmatic-hydrothermal event related to monzogranite. Tourmaline is a valuable prospecting indicator of W–Sn mineralization.

The Dajingou gold deposit is one of the typical gold deposits in the Quruqtagh metamorphic terrane, north of the Tarim Craton. The deposit mainly comprises gold-bearing quartz veins hosted in Precambrian metamorphic rocks and structurally controlled by the subsidiary faults and ductile shear zone. To determine the age of gold mineralization in the Dajingou deposit, a single sericite 40Ar/39Ar age of 829.4 ± 4.8 Ma (MSWD = 0.57) and hydrothermal zircon weighted average U–Pb ages (812 ± 15 Ma, MSWD = 3.2) from auriferous quartz veins were obtained in this study, indicating that mineralization occurred in the mid-Neoproterozoic (ca. 0.83 Ga), corresponding to regional metamorphism of the Tarim Craton, termed the Tarim orogeny. The Dajingou deposit is the first Precambrian gold deposit identified in North Xinjiang, NW China. The δ18O and δD of quartz ranges from 14.7‰ to 15.9‰ and −104‰ to −75‰, respectively; the calculated δ18OH2O of the fluids ranges from 0.9‰ to 5.0‰. This suggests that the ore-forming fluids in the Dajingou gold deposit were derived from dehydration of metamorphic rocks during regional metamorphism, with a subsequent input of meteoric water. Based on its similarities with typical orogenic gold deposits, the Dajingou deposit is proposed to be an orogenic gold deposit formed during the mid-Neoproterozoic Tarim orogeny in the Tarim Craton.

The Awanda gold deposit is located within the southern Tianshan Accretionary Complex, a late Paleozoic orogenic belt in the northern margin of Tarim block in NW China. The gold mineralization here occurs in primarily within shear zones and secondary s faults with quartz mica schist as the principal host rock. The sulfide mineral assemblage is dominated by arsenopyrite, and pyrrhotite, with minor pyrite and gudmundite. Alteration includes silicification, sericitization and rare carbonatization. The measured δ 18 O values for the gold-bearing quartz range from 15.9 to 20.3‰, and the estimated δ 18 O fluid values range from 7.8 to 12.2‰. The δD values for fluid inclusions from quartz range from − 116.3 to − 87.6‰. The δ 34 S values of gold-associated sulfide minerals range from − 3.6 to + 6.2‰, and the calculated δ 34 S H2S values of H 2 S for the hydrothermal fluids range from − 4.8 to + 5.8‰, with an average of − 0.4‰. Lead isotopic compositions of sulfides from gold-bearing ores show 206 Pb/ 204 Pb ratios ranging from 17.4625 to 18.5356, 207 Pb/ 204 Pb ratios from 15.4943 to 15.6468, and 208 Pb/ 204 Pb ratios from 37.8825 to 38.8238, respectively. Collectively, the isotope (H, O, S, Pb) characteristics suggest that the ore-forming fluids were of metamorphic origin derived through dehydration of carbonaceous black shale with the sulfur sourced from crustal components, and the lead from a mixture of host rocks and ore-forming metamorphic fluids. This deposit can be classified as orogenic gold deposit and share many major characteristics with those of Muruntau-type gold deposits. During late Paleozoic, the southern Tianshan Accretionary Complex was intensely deformed into an orogenic belt by folding and thrusting, generating regional thrust faults at different scales. The ore-controlling subsidiary faults also formed subsequently, with the ore-forming fluids derived from dehydration of deeply buried carbonaceous black shale and the ore fluids channeled into shear zones leading to gold precipitation.

A 418 Ma albite porphyry dike emplaced in a 429 Ma granite pluton in the Hersai porphyry copper deposit (Nom, East Junggar, China) consists of euhedral and pale-orange luminescing albite phenocrysts and groundmass, zircons, blue-violet luminescing apatites and chalcopyrite–sphalerite-rich miarolitic cavities. This dike is characterized by two-domain textures presented by albites and disseminated intergranular miarolitic cavities, and by geochemical features of continental island arc and adakitic intrusions. The miarolitic cavities consist of various minerals that crystallized in the following sequence: epidote, rutile and sphalerite–chalcopyrite solid solution, titanite and K-feldspar; chalcopyrite with pyrite inclusions; and chlorite, zoisite and calcite. The miarolitic cavities exhibit magmatic to hydrothermal internal textures, such as aplitic textures presented by intergrowths of albite, epidote, rutile and sphalerite–chalcopyrite solid solution, zoning and intersertal texture, poikilitic textures, and layered chlorites. The sphalerite contains a high concentration of exsolved chalcopyrite (up to 10 vol.%). The rutiles intergrown with epidotes contain 137 to 528 ppm Zr corresponding to Zr-in-rutile temperatures of 507 to 625 °C, and the rutiles intergrown with sphalerite–chalcopyrite solid solutions have 381 to 420 ppm Zr and Zr-in-rutile temperatures of 585 to 605 °C. Mineralization temperatures of sphalerite–chalcopyrite solid solutions are possible approximately 600 °C. The formation of the chalcopyrite–sphalerite-rich miarolitic cavities is related to interstitial residual sulfide-rich fluids. The copper–zinc albite porphyry may represent a copper–zinc (Cu–Zn) subtype of porphyry copper deposit that formed as a transition between late magmatic and classical hydrothermal porphyry copper deposits.