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This study investigates apatite and anhydrite inclusions in zircon from ore-forming intrusions in the Duolong porphyry Cu-Au deposit, central Tibet (Fig. 2 Geological characteristics (a) and cross sections (b, c) of the Duolong porphyry Cu-Au deposit, central Tibet, showing sample locations (Li et al. [21], [25]) The Duolong magmatic complex evolved from diorite to granodiorite porphyry and quartz diorite porphyry, the hosts of Cu-Au mineralization (Fig. Apatite inclusions ( I n i = 98) in zircon from the granodiorite porphyry and quartz diorite porphyry have F contents of 1.14-2.99 wt%, Cl of 0.16-2.51 wt%, and SO SB 3 sb of 0.04-1.38 wt%, with minor SiO SB 2 sb (0.05-1.39 wt%), MnO (0.12-0.93 wt%), Na SB 2 sb O (0-0.28 wt%), and FeO (0.01-0.64 wt%; Supplementary Table 1). Apatite and anhydrite were randomly enclosed by zircon crystals, which were later hosted in ore-forming porphyries One apatite inclusion coexisting with an anhydrite inclusion in a single zircon grain contains 0.69 wt% SO SB 3 sb with a low I X i SB F sb / I X i SB Cl sb ratio of ~ 1.2 (Fig. [Extracted from the article]

The Shuiyindong Carlin-like gold deposit, the largest one of this type in China, is located in the Late Paleozoic–Early Mesozoic Youjiang basin. The pyrites in the studied ore bodies (No. I to V) can be divided into four main types plus several sub-types: (1) As-poor pyrites include Py1 (Py1a and Py1b), Py2, and Py3; and (2) As-rich pyrite Py4 (Py4a and Py4b). In situ LA-ICP-MS analyses show that the As-rich pyrite also contains higher Au, Cu, Sb, and Tl than the other pyrite types. In situ NanoSIMS analyses show the δ34S variation of Py1 (48.1~67.5‰), Py2 (2.4~7.6‰), Py3 (9.2~14.2‰), and Py4 (− 3.0~6.6‰), with the average values of 58.1‰, 5.1‰, 11.4‰, and 3.1‰, respectively. The large δ34S variations of As-poor pyrites may reflect a sedimentary source. However, the narrow ranges of δ34S values for the As-rich pyrite (Py4) may not reflect a sedimentary but a magmatic or metamorphic origin. A metamorphic sulfur source of Py4 is favored due to paucity of coeval magmatism in the region and decreasing variations of δ34S values from Py1 to Py4. Integrated transmission electron microscope (TEM) and NanoSIMS element mapping show that the distribution and concentration of Au are discordant with As and Cu at the submicron scale, also implied by the occurrence of some of Au as nano-submicron particles in Py4. Overall, our new data indicate that the ore fluids were not only enriched in Au but also in As, Cu, and S. Taking an alternative of fluid oxidation probably resulting in the decreasing δ34S values of Py4, our result of I to V orebodies indicates the mixing between the underlying metamorphic fluid and meteoric water. Integrated variations in δ34S and As-Au-Cu correlations across individual pyrite grains infer the physicochemical changes of aqueous and/or aqueous-carbonic fluids along migration paths. [ABSTRACT FROM AUTHOR]