Geochemical Anomalies And Prospecting Of Silver Deposit In Xishanwanyangchang, Inner Mongolia

Xishanwanyangchang silver deposit is located in the east section of Langshan-Zha’ertaishan Mesoproterozoic rift zone of the northern margin of north china plate. There aregood ore-forming geological background and geochemical anomalies in the mining area.Through the comprehensive analysis of geochemical data, article framed the potential areasbased on the mine geological background.The silver deposit is hosted in the volcanic rock of lower series of CretaceousBainvyangpan Formation (K1bn). Its host rock mainly is rhyolite，rhyolite porphyry andrhyolite breccia. The deposit is clearly controlled by fractures. Faulted structure iswell-developed in the mine area, and it provides adequate structural conditions for volcanichydrothermal activity and mineralization.Based on the test distribution, cumulative frequency method and fractal method toanalysis the soil geochemical data and the rock geochemical data, the analyses of test dataindicate the element anomaly threshold, generate the single element anomalies, and reflect therelative enrichment factor. By using correlation analysis, cluster analysis, factor analysis todetermine the mineral assemblages, and make the elements assembled anomaly maps. Thesoil geochemical element is divided into three groups, namely Cu-Pb-Zn-Ag、Sb-W-Bi andMo-As-Au. Anomalies of Cu-Pb-Zn-Ag, namely factor1, distributes along the volcanic, is theprospect area of silver deposit; Anomalies of Sb-W-Bi, namely factor2and factor3,distributes in the middle and north part of the area; Anomalies of Mo-As-Au, namely factor4, coincides with the anomalies of Sb-W-Bi. The geochemical element of rock is divided intothree groups either, namely Mo-Sb-Au、Cu-Pb-Zn-Sn andAg-W-As.Anomalies of Mo-Sb-Au,namely factor1, distributes widely, and it is more meaningful for prospecting; Anomalies ofCu-Pb-Zn-Sn, namely factor2, distributes at the southwest corner、southeast corner and thenorth part, speculate for the process of high temperature mineralization; Anomalies ofAg-W-As, namely factor3and factor4, is the prospect area of silver deposit. The elementsassembled anomalies calculated by using multivariate normal distribution theory, distributesmore collective relatively, with clear concentration heart and regular shape. These anomalieswhich may match with some others sterically are more meaningful than single elementanomaly, and meanwhile assembled anomaly is better in accordance with the geologicalcharacteristics of element association in mineralization and hydatogenesis.According to the geochemical anomalies, the regional geological background, formation,fracture structure, magmatic rocks, known mine sites and other features, five prospecting areas(Y-1、Y-2、Y-3、Y-4、Y-5) have been delineated, Y-2and Y-4for ClassAmetallogenicprediction area, Y-1、Y-3、Y-5for Class C metallogenic prediction area. Y-2and Y-4forecasting area is located in the middle of the study area, along the direction of volcanic rock,influenced by tectonic action. It is the favorable target areas for silver deposit. Y-1predictionarea is located in the northern part of the study area. The lining value and anomalous peak ofPb, Zn is higher. The combination of elements nested exception is better. Based on theanalyses above predicate Y-1area is the secondary prospecting areas to find silver deposit.Y-3forecasting area is located in the southwest of the research region. Au element anomaly inthe area is stronger. Speculation has elements Au ore prospects. Y-5forecast area located inthe southeast of the study area. The anomalous characteristics ofAu、Sb、Cu、Pb、Zn elementsis better, showing excellent prospecting foreground.Learn the concept of index of geoaccumulation，normalize the main ore-formingelements and associated elements Ag, Au, Cu, Pb, Zn, Mo, As and calculate thegeoaccumulate. Then generate the elements integrated anomaly map, it verified to the targetof mineralization. Arrangement of exploration projects of coastean and misering indicate thesilver deposit spread along the direction of the main volcanic, the main hose rocks aresilicified pyritized rhyolite and rhyolite breccia. Ag element content gradually reduce fromline13to25. The main ore located between the line to13to17and mian alteration is pyrite,limonite, chloritization and fluorite veins.