Fluid inclusions and stable isotope study of quartz-tourmaline veins associated with beryl and emerald mineralization, Kafubu area, Zambia

Three evolution stages of quartz-tourmaline ± beryl mineralization are inferred from fluid isochores and isotope thermometry: early (620-400 MPa and 450-350 °C), main (400-150 MPa and 450-350 °C) and late (∼250-200 MPa and 350-280 °C). The early stage includes formation of banded quartz-tourmaline rocks and of some quartz-tourmaline veins. Most of the studied quartz-tourmaline veins and all studied beryls were formed within the main stage. Late stage corresponds to the formation of late quartz-tourmaline veins with lamellar tourmaline-quartz intergrowths.