ORE CONTROLLING FACTORS AND MINEROGENIC PROGNOSIS OF WESTERN METALLOGENIC BELT OF SOUTH BELT OF BEISHAN,GANSU

This paper deals with the metallogenic environment and ore controlling factors of gold ore deposits in western section of south belt of Beishan. In addition,their minerogenetic epoches and temporal-spacial distribution regularities are also discussed. The ore-formation of gold is controlled by lithology、rock body and structure. Ordovician,Carboniferous and Permian Au-rich volcano-sedimentary rocks are the source bed;Late Caledonian-Hercynian granite series correlate closely with the gold deposits;Deep faults or large regional faults control the mineralization zones. The gold ore belt consist of a series of gold deposits of different genesis and types. The gold deposits were formed on the foundation of the source beds and source rocks though reworking and enrichment of Hercynian structure-magmatic activities. Based on new progress and information on prospecting and anomalies of geochemistry and heavy concentrate,and its distribution,it is concluded that sixteen prospecting regions for ore-search are the favourable localities for gold deposits,where there are more potential of gold resources. Breakthrough in gold prospecting in the area might be achieved through detailed geological work and integrated study.