Geology and geochemistry of reworking gold deposits in intrusive rocks of China—II. Gold deposits and their genesis

Gold deposits in intrusive masses include the veinlet dissemination, quartz vein and veinlet dissemination + vein types. They are distributed in fracture zones along the endocontact zone of a batholith or in the centre and edge of a stock. The metallogenic epochs are Yenshanian, Hercynian, Archean, Proterozoic and Himalayan. The gold deposits are characterized by a big difference in time span between gold mineralization and the formation of host masses. Ore-forming materials were derived from the masses and auriferous strata and ore-forming fluids came from meteoric and formation waters. When circulating water was heated by ascending heat flow, gold would be extracted, concentrated and transported from auriferous rocks and then precipitated in the masses during the late tectonic movement. Finally gold deposits were formed in the intrusive masses.