Determination of the age of gold deposits in southeastern Guizhou: with a discussion of the Caledonian Hunan-Guizhou gold ore belt

Abstract：Gold deposits in southeastern Guizhou are quartz vein type gold deposits hosted in the Neoproterozoic low-grade metamorphic series. The protoliths of the metamorphic rocks are represented by a volcanic-sedimentary sequence composed of tuff, tuffaceous sandstone and siltstone with a distinct rhythmic ribbon texture, reflecting an environment of turbidite sedimentation. The occurrence of quartz veins is controlled by anticlines and shear faults. Two types of vein may be distinguished: conformable interlayer veins and filling veins in fracture zones. The mineral composition of quartz veins is rather simple, and in addition to quartz, the veins mainly contain sulfide minerals and some minerals captured from wall rocks. Rb-Sr and isochron dating of inclusions in quartz from five gold deposits indicates that their age is Caledonian, which is consistent with the age of gold deposits of the same types of gold deposit in western Hunan adjacent to Guizhou. A Caledonian Hunan-Guizhou gold belt of gold has been delineated according to the lithology of host strata, geological evolution and structural environment, which will be of great reference value for mineral prospecting.