The Miaoya syenite and carbonatite complex is located in the southern margin of the South Qinling belt, central China. LA‐ICP‐MS zircon U–Pb dating reveals that the syenite and carbonatite have crystallization ages of 445.2 ± 2.6 Ma (MSWD = 0.66) and 434.3 ± 3.2 Ma (MSWD = 1.08), respectively. Both syenite and carbonatite display low ISr values (0.7004 to 0.7053) and depleted εNd(t) values of +1.1 to +5.5, with one‐stage Nd model ages of 0.65 to 0.94 Ga. Their zircon εHf(t) values are also similarly positive (+3.1 to +8.9), and one‐stage Hf model ages range from 0.71 to 0.92 Ga. Whole‐rock geochemistry suggests that the syenite belongs to the shoshonitic series and both syenite and carbonatite show identical REE and trace element patterns. The coeval intrusive ages, similar geochemical and Sr–Nd–Hf isotopic compositions suggest that the Miaoya carbonatite and associated syenite are genetically related to each other. We consider that the carbonatite could be a final product by protracted fractionation of a CO2‐rich alkaline melt. The depleted εNd(t) and zircon εHf(t) isotopes also indicate that the associated syenite and carbonatite could be originated from a mantle‐derived magma. The sources are likely composed of dominated HIMU mantle and minor EMI mantle. We propose that the Silurian Miaoya Complex was formed in the extensional rifting setting, associated with the mantle upwelling. Copyright © 2016 John Wiley & Sons, Ltd.

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The Liushanyan deposit is an important volcanic-host massive sulfide (VMS) Cu-Zn deposit in the Qinling-Tongbai-Dabie orogenic belt, central China, with reserve of 2.38 Mt Cu and 16.11 Mt Zn. Orebodies occur in the meta-quartz keratophyre of the Liushanyan formation. In this paper, we present textural features and laser ablation ICP-MS U-Pb dating results of zircons from the ore-bearing mylonitized meta-quartz keratophyre. The hydrothermal zircons are distinct from metamorphic zircons in this rock, showing low cathodoluminescence (CL) response and hydrothermal rims (black in CL images). They have relatively flat light rare earth element patterns and high La content and low (Sm/La) N and Ce/Ce* values. These features are typical of hydrothermal zircons. The cores of metamorphic zircons yield a weighted mean 206 Pb/ 238 U age of 900 ± 26 Ma, interpreted as the volcanic and related VMS mineralizing age. Two much younger events are also recorded by zircons in this rock: (i) the Early Silurian amphibolites-greenschist facies metamorphism at 435 ± 26 Ma; and (ii) the growth of hydrothermal zircons at ca. 241 ± 1 Ma, associated with the ductile shear deformation. The Silurian metamorphic event is probably associated with the arc-continent collision, while the Triassic ductile deformation event formed in the final continent-continent collision setting.

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