Abstract:
The Qiyugou No.189 gold deposit in western Henan is a medium-sized one newly discovered in the Xiong'ershan ore-concentrated area on the southern margin of the North China Block in recent years.The gold orebodies are hosted in the Early Cretaceous hornblende monzonitic granite.The upper part is veinlet disseminated gold mineralization, and the lower part is hydrothermally mineralized Au-bearing breccia, which shows porphyry mineralization characteristics.Although predecessors carried out research work, there are still big controversies about the alteration zonation and mineralization process of the deposit.Based on the field investigation and analysis of alteration zonation, micro-area analysis technology was used to test and study the main-trace elements and sulfur isotopic compositions of pyrite in different alteration zones.The wall rock alteration zonation is characterized by potassium feldspar zone-sericitization zone-propylitization zone from the center to the periphery of the orebody.Gold mainly occurs in the form of fissure gold, intergranular gold and inclusion gold in pyrite and other sulfide, and the content of invisible gold is low.From the potassic zone, through the phyllic zone, to the propylitic alteration zone, the contents of Ag and Bi tend to increase, while the contents of As, Sb, Zn, Mn, Mo and Sn, etc.show no obvious changes.The in-situ sulfur isotope composition indicates that the ore-forming material originates from deep magma.The analysis of its metallogenic process indicates that complexes and Te-Bi melts play an important role in the migration and enrichment of gold.