Fluid inclusions, isotopes, and geochronology data constraints on the mineralization of the Carboniferous volcanogenic massive sulfide Xiaorequanzi Cu–Zn deposit in the East Tianshan, NW China

•Mineralization associated with volcanism and subvolcanic intrusions can be identified at Xiaorequanzi.•Fluid mixing and boiling played a vital role in controlling sulfide precipitation.•Magmatic hydrothermal fluids contribution increased from the early to late mineralization stages.•Mineralization time occurred during 352–357 Ma and 342–345 Ma.