The Shaxi Pb-Zn-Ag deposit is situated in the central YDT and adjacent to the Rongyicuo granite. The orebodies are hosted within the Upper Triassic Tumugou Formation, a shallow metamorphic rock unit. The lithological assemblage of the Tumugou Formation is primarily composed of dark gray feldspar quartz sandstone interbedded with sericite sandy slate and carbonaceous shale. Further intercalations include quartz sandstone and calcareous slate of variable stratigraphic thickness. Eight orebodies have been delineated at Shaxi, with lengths ranging from 30 to 4,450 m. These orebodies commonly occur as stratiform, regular vein-like, and lenticular forms. The No.1, No. 2 and No.3 orebodies are the largest in scale, with a length of 2450–4450 m, controlled slope depth of 110–257 m and thickness of 1.12–2.21 m. The grades for the Ag, Pb and Zn range from 299.04 to 560.55 g/t, 6.97% to 11.70% and 0.48% to 4.96%, respectively.
Hydrothermal alterations are dominated by silicification and carbonatization, followed by sericitization and chloritization. Furthermore, hornfelsification and skarnization are well developed adjacent to the Rongyicuo intrusion.
The ore-forming process can be broadly categorized into three distinct stages. In stage I, disseminated pyrrhotite and chalcopyrite are present at the edges of quartz veins. Stage II mainly consists of sphalerite, galena and quartz. Furthermore, silver-bearing sulfosalt minerals, native bismuth and electrum are commonly hosted by galena, replacing pyrrhotite in the form of fine-grained discrete minerals and solid solutions. The quartz-calcite stage (III) comprises quartz and minor calcite, occurring as vein-like forms cross-cutting the earlier Pb-Zn ores.

Other Regions, Features and Areas containing this locality

References