Abstract:
Located at the western section of Calidonian Fold Belt in North Qilian Mountain, the Dishuishan gold deposit is distributed in NWW fault zone.The paper has studied the structural-lithofacies characteristics and its geochemical elements variation of Au2 orebody through field survey and microscopic observation and sample testing.The result show that:①There are two periods of deformation occurred in this shear zone, the early deformation is the ductile-brittle shear deformation in the process of oblique thrust from north to south, and the late deformation is brittle deformation in the process of oblique slide.②According to the results of elemental analysis, the content of gold is gradually increased from andesitic crystal tuff facie zone→ mylonitize andesitic crystal tuff facie zone→ altered cataclastec rock facie zone→ gold mineralization altered cataclastic rock facie zone, and which is significantly enriched in quartz vein.Furthermore, according to the correlation analysis, Au and Ag correlation is best, which is followed by Pb, Mo and has general correlation with the As and Hg.Research suggests that early ductile-brittle deformation in NWW fault zone is advantageous to the activation migration of ore-forming elements and provides the place for the preliminary enrichment of gold; late brittle deformation was mainly formed various tension fissure and tectonic fracture zone, with the enrichment of gold element to form gold orebodies by the transition of tectonic regime.