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The Awulale Iron Metallogenic Belt (AIMB) has developed many medium–large iron deposits, of which the Zhibo iron deposit is selected as the research object in this paper. The Zhibo deposit's ore primarily consists of magnetite as the main mineral, accompanied by extensive epidotization. The mineral assemblage includes diopside, albite, actinolite, epidote, chlorite, K-feldspar, quartz, calcite, chalcopyrite, and pyrite. Magnetite is classified into two groups based on sulfide content and mineral assemblage (MagI for sulfide-free and MagII for sulfide-rich ores). Two-stage mineralization of magnetite has been identified based on mineral assemblages and paragenesis, including the magmatic stage MagI and hydrothermal stage MagII. Mag I shows inhomogeneous backscattered electron (BSE) textures and consists of BSE-light and -dark domains (Mag I-L and MagI-D). Seven subtypes of magnetite have been recognized in this deposit. MagI-L and MagI-D have formed in the magmatic stage and show BSE images in light and dark colors, respectively. MagI-L is anhedral to subhedral and is inclusion-free. MagI-D has mainly replaced MagI-L along fractures and contains inclusions and pores. MagII has formed in the hydrothermal stage and is characterized by coupled dissolution–reprecipitation (DRP) textures. It can be divided into five sub-generations, that is, MagII-1, MagII-2, MagII-3, MagII-L, and MagII-D. MagII-1, MagII-2, and MagII-3 comprise the core–mantle–rim texture, while MagII-L and MagII-D comprise the core–rim texture. MagII-1 is BSE-light and is enriched with inclusions and pores. MagII-2 has partly replaced MagII-1 and exhibits oscillatory zoning under BSE imaging. It also contains inclusions. BSE-light MagII-3 occurs as overgrowth along MagII-2 margins and is inclusion-free. MagI magnetite is enriched with V, Cr, and Ni, whereas MagII is enriched with W, Ta, Nb, Sr, Sb, Sn, Y, Zr, Mg, Al, and Ti, indicating a decreased temperature of magnetite formation. MagI-L crystallizes from the original magma, while MagI-D is formed from the residual magma enriched with incompatible elements. MagII crystallizes from later multiple hydrothermal activities through the dissolution of early magnetite and the re-precipitation of later magnetite or from MagI-D which has later undergone a hydrothermal overprinting process. According to the texture and chemical composition of magnetite from the Zhibo deposit, we suggest that the Zhibo iron deposit was formed from the initial magmatic origin and then underwent a hydrothermal overprinting process. [ABSTRACT FROM AUTHOR]

[Display omitted] • Textural and compositional variations in apatite from mineralized intrusions indicate magmatic mixing. • The low-viscosity magma is essential for the formation of porphyry Mo deposits. • A large volume magma chamber below the Suyunhe Mo deposit was inferred. Textural and compositional variations in apatite and amphibole from mineralized granite (G), granite porphyry (GP), granodiorite porphyry (GDP), and barren tonalite porphyry (TDP) in the Suyunhe ore district, Xinjiang province, NW China revealed differences in their petrogenesis, magmatic properties and mineralization potentials. The higher Cl contents (0.09–0.18 wt%) and Cl/F ratios of apatite, and the higher Mg/(Mg + Fe2+) ratios (0.54–0.62) of amphibole in the barren TDP indicate that the parental magma was mainly generated via melting of the lithospheric mantle. In contrast, the parental magmas of the GDP, G, and GP were mainly derived from melting of the juvenile lower crust. The enrichment of Mn, Y, and heavy rare earth elements (HREEs), depletion of Sr, and strong negative Eu anomalies of the apatite from the GP indicate that it underwent a high degree of fractional crystallization. Moreover, the reverse core-to-rim compositional variations in REE and Sr contents and the La/Y ratios observed in some of the apatite grains, as well as the distinct differences in the major-element compositions (e.g., CaO, MnO, SiO 2 , and Ce 2 O 3) of the individual zones within single apatite grains, indicate magmatic mixing. The calculated magmatic viscosities (Logη = 4.8–5.0 Pas) at Suyunhe remained below the average value for granitic melts (mostly Logη > 5 Pas) at the same temperature. These results support the hypothesis that low-viscosity magma (e.g., Logη < 5 Pas) may be essential for the formation of porphyry Mo deposits. The physicochemical conditions (including temperature, pressure, and H 2 O content) estimated based on the amphibole in the mineralized intrusions indicate the existence of a deep magma chamber with a large volume, which continuously released volatiles (e.g., fluorine and water) and effectively reduced the viscosity of the magma. [ABSTRACT FROM AUTHOR]