Geological And Geochemical Characteristics And Metallogenic Prediction Of Gold Polymetallic In Guozhangzi Area,Hebei Province

The Guozhangzi area,located on the northern margin of the North China block(NCB),is a potential gold polymetallic metallogenic belts in the NCB.The region is bounded by the Pingfang-Sangyuan Fault and the Nankou-Qinglong Fault.However,in recent years,mineral exploration in this area has not achieved good results.Exploration geochemical method has been proved to be one of effective ore exploration methods,especially in gold exploration.In this paper,we carried out mineralization prediction based on the exploration geochemical method and geological constrains,and delineated target areas for prospecting of gold polymetallic deposits in the Guozhangzi area.The results will provide scientific evidence of resource exploration in the Guozhangzi area.Geology-geochemical space information database has been established based on the geological and geochemical data of 1:50,000 stream sediments in the study area.The data was processed using Map GIS and GeoExpl softwares.The distribution and content of the elements(e.g.,Au,Cr,Co,Ni,Cu,Zn,Mo,Cd,Sb,W,Pb,Bi,As,Hg,Sn and Ag)show that Au,Ag,Cd,Pb in the stream sediments with enrichment coefficient higher than 1,indicating these elements are the target elements and related elements in the Guozhangzi area.Subsequently,the element geochemical anomaly maps of the study area have been drawn.The geochemical anomalies were identified,and its characteristics were studied based on the geochemical anomaly maps.This study also shows that the main ore-controlling factors of gold polymetallic mineralization in the Guozhangzi area are Archean strata,NE trending faults and Yanshanian porphyry.Prospecting criteria for gold polymetallic deposits in the Guozhangzi area has been elaborated based on the geology of typical ore deposit and the relationship between geochemical anomaly and gold deposit.It worth to note that altered granite porphyry and quartz monzonitic porphyry are the most direct signs of ore prospecting.Finally,four different levels of abnormal areas were delineated,and one target area was determined in the Guozhangzi area following geochemical anomalous evaluation using the method of the prospecting significance classification-mineralization type classification-analysis of geological and prospecting sign in the anomalous area-analogy with typical deposit.