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The Jiama deposit, a significant porphyry‐skarn‐type copper polymetallic deposit located within the Gangdese metallogenic belt in Tibet, China, exemplifies a typical porphyry metallogenic system. However, the mineral chemistry of its accessory minerals remains under‐examined, posing challenges for resource assessment and ore prospecting. Utilizing electron microprobe analysis and LA‐ICP‐MS analysis, this study investigated the geochemical characteristics of apatite in ore‐bearing granite and monzogranite porphyries, as well as granodiorite, quartz diorite, and dark diorite porphyries in the deposit. It also delved into the diagenetic and metallogenic information from these geochemical signatures. Key findings include: (1) The SiO2 content, rare earth element (REE) contents, and REE partition coefficients of apatite indicate that the dark diorite porphyry possibly does not share a cogenetic magma source with the other four types of porphyries; (2) the volatile F and Cl contents in apatite, along with their ratio, indicate the Jiama deposit, formed in a collisional setting, demonstrates lower Cl/F ratios in apatite than the same type of deposits formed in a subduction environment; (3) compared to non‐ore‐bearing rock bodies in other deposits formed in a collisional setting, apatite in the Jiama deposit exhibits lower Ce and Ga contents. This might indicate that rock bodies in the Jiama deposit have higher oxygen fugacity. Nevertheless, the marginal variation in oxygen fugacity between ore‐bearing and non‐ore‐bearing rock bodies within the deposit suggests oxygen fugacity may not serve as the decisive factor in the ore‐hosting potential of rock bodies in the Jiama deposit. [ABSTRACT FROM AUTHOR]

The Sinongduo mining region includes two types of mineralizations: the epithermal and the carbonate‐hosted Pb‐Zn‐Ag deposits. Despite being studied for many years, the ore formation process and genesis of the carbonate‐hosted Pb‐Zn‐Ag deposits remain poorly understood. The Pb‐Zn‐Ag ore bodies occur as veins and are hosted by limestone and dolostone of the Permian Xiala Formation. Three sulfide mineralization substages have been identified at the Sinongduo carbonate‐hosted deposit. Indium coupled with Cu, Co and Sn was incorporated into sphalerite as substitutions: 2Zn2+ ↔ Cu+ + In3+, (3n/2 + 1)Zn2+ ↔ Co2+ + nIn3+ or (2n + 1)Zn2+ ↔ Co2+ + n(Cu+ + In3+) (n > 1) and 4Zn2+ ↔ Sn2+ + 2In3+. Sphalerite and pyrite in the mineralization stage display δ34S values in a narrow range of +5.7‰ to +11.3‰, which are similar to those of Palaeocene igneous rocks, indicative of a magmatic source of sulfur. We present systematic carbon‐hydrogen‐oxygen isotope results that further support a magmatic source for the ore‐forming fluids that were influenced by meteoric water. Furthermore, the Pb isotope compositions of sulfide minerals in the Sinongduo carbonate‐hosted deposit overlap with the values of coeval Linzizong volcanic rocks and are similar to those of Indian Ocean sediments, indicating upper crustal sources of metals. We conclude that the Sinongduo carbonate‐hosted Pb‐Zn‐Ag deposit is a medium‐ to low‐temperature magmatic‐hydrothermal deposit related to Linzizong magmatism. [ABSTRACT FROM AUTHOR]

We report zircon U Pb age and Hf isotope and whole-rock major and trace element and Sr Nd isotope data for magnesian andesites from the Kongnongla area, central Tibet. These Kongnongla magnesian andesites are directly in contact with high-Nb basalts and are part of the Baila–Lanong ophiolitic mélanges. Zircon U Pb dating shows that the magnesian andesites crystallized at ca. 158 Ma. The samples are characterized by moderate SiO 2 (59.3–61.7 wt%), high MgO (3.74–4.69 wt%), Fe 2 OT 3 (4.95–5.30 wt%), Ba (570–1320 ppm), and Th (6.5–7.0 ppm) contents, and low (87Sr/86Sr) i (0.704491–0.704857), and Sr/Y (17.5–24.0) ratios. The samples also exhibit enrichments of compatible elements, such as Cr (110–150 ppm) and Ni (24.7–36.5 ppm), and display fractionated rare earth element (REE) patterns with light REE enrichment relative to heavy REEs. Negative zircon ε Hf (t) values (−10.8 to −15.7) and whole-rock ε Nd (t) values (−3.85 to −6.12) of the Kongnongla magnesian andesites are similar to those of DaruTso magnesian andesites, Hohxili high magnesian andesites, and sediments of the Mugagangri Group. We propose that the Kongnongla magnesian andesites were formed by the interaction between slab fluids, subducting sediments, and overlying mantle under high-temperature–low-pressure conditions. Based on previously published data and the regional geology, we also suggest that these magnesian andesites were generated in a back-arc setting caused by the southward subduction of the Bangong–Nujiang oceanic lithosphere during the Late Jurassic. • The Dongqiao area is a microcontinent preserved in the Bangong–Nujiang suture. • The Kongnongla magnesian andesites formed in a back-arc setting. • Southward subduction of the Bangong-Nujiang Ocean triggered back-arc spreading. [ABSTRACT FROM AUTHOR]