Apatite records metamorphic and hydrothermal fluid evolution at the large Shuangqishan orogenic gold deposit, SE China

Orogenic gold deposits are currently the world’s major source of Au, but uncertainty exists in timing mineralization relative to ages host rocks, metamorphism, and magmatism. Consequently, origin detailed evolution ore-forming fluids have long been elusive. Apatite occurs widespread various types mineral can provide valuable information on ore genesis. Here, we present textural, high-precision situ U-Pb geochronological, trace elements, Sr isotope data for metamorphic hydrothermal apatite Shuangqishan deposit southeastern China. These data, together with dates metavolcanic granitic mafic intrusive allow us precisely constrain reconstruct history there. The crystals within auriferous quartz veins be grouped into three generations according cathodoluminescence imaging element concentrations: Ap1 precipitated pre-mineralization stage, whereas Ap2 Ap3 formed stage. Metamorphic displays a negative Eu anomaly, indicating predominance Eu2+ crystallization under relatively reduced conditions. On other hand, syn-gold marked positive anomalies. Radiometric at ca. 461 Ma, xenotime from gave 425 ± 15 Ma 416 interpreted as time mineralization. Emplacement determined by zircon 439 2 intrusion 427 dike mining district. Mineralization, therefore, postdates metamorphism local rocks magmatism ?35 24 m.y. ?14 17 m.y., respectively. synchronism genesis provides additional evidence mantle derivation fluids. highly radiogenic 87Sr/86Sr ratios obtained (0.7178?0.7302) consistent its precipitation fluid. Higher concentrations (Ap2 = 1228?2884 ppm, 2325?3169 ppm) anomalies (Eu/Eu*: 1.03?2.84, 2.00?4.30) lower variable (0.7100?0.7165) (0.7086?0.7116) mainly ascribed extensive fluid-wall rock exchange during It is therefore suggested that fluid-rock reaction played vital role observed apatite. Our study highlights usefulness novel robust geochemical, isotopic indicator complex processes deposits.