Study on the physical and chemical conditions of ore formation of Hetai ductile shear zone-hosted gold deposit and discovery of melt inclusions.

The Chinese deposit occurs in a deep-seated fault mylonite zone. Melt inclusions, fluid-melt inclusions and organic inclusions from ore-bearing quartz veins and mylonites at the 0, 80 and 160 m levels have provided new evidence for the deposit's genesis and for the mechanisms of gold deposit metallogeny in shear zones. Homogenisation temperatures and compositions of the inclusions were determined, Au grades and Au/Ag ratios at different levels correlated with contents of K, Na, Ca, SO4, HCO3, Cl, H2O and C2H2, and the electron microscopy and energy spectra of daughter minerals in the vein melt inclusions analysed. It is concluded that regional metamorphism and shearing played an important role in deposit formation, giving rise to multi-stage aluminium silicate melts during long-term geotechnical reworking of the metasedimentary rocks.
The Chinese deposit occurs in a deep-seated fault mylonite zone. Melt inclusions, fluid-melt inclusions and organic inclusions from ore-bearing quartz veins and mylonites at the 0, 80 and 160 m levels have provided new evidence for the deposit's genesis and for the mechanisms of gold deposit metallogeny in shear zones. Homogenisation temperatures and compositions of the inclusions were determined, Au grades and Au/Ag ratios at different levels correlated with contents of K, Na, Ca, SO4, HCO3, Cl, H2O and C2H2, and the electron microscopy and energy spectra of daughter minerals in the vein melt inclusions analysed. It is concluded that regional metamorphism and shearing played an important role in deposit formation, giving rise to multi-stage aluminium silicate melts during long-term geotechnical reworking of the metasedimentary rocks.