GEOLOGICAL CHARACTERISTICS OF DAQIAO GOLD DEPOSIT IN GANSU PROVINCE AND ITS SIGNIFICANCE IN PROSPECTING FOR GOLD DEPOSIT

Daqiao gold deposit is located in the north margin of Indo-Sinian fold belt of south Qinling,and in the east section of Hezuo-Linagdang gold-antimony-mercury metallogenic belt.The gold mineralization exists in the lower member of Triassic Formation in which the siliceous breccia presents itself in bedded style,unalter-able level,and marked sedimentary characteristics.The gold mineralization is strictly controlled by siliceous breccia rock,gold ore bodies present themselves in bedded or like bedded style.The textures of ore are mostly granular,metasomatic relict,and filling up interspace,and its structures are mostly disseminated,spotted,vein-stockwork,brecciated,stratified,and massive.The gold deposit has remarkably strata-and lithology-controlled characteristics,and belong to sedmentary and reformation type deposit.Discovering of the gold deposit has an im-portant signigficance in prospecting for gold in west Qinling.