Integrated Information Metallogenic Prediction Of Silver-polymetallic Deposit In Xishanwanyangchang,Inner Mongolia

Xishanwanyangchang silver deposit is located in the east section of Langshan Zha’ertaishan Meso-Neoproterozoic rift zone of the north china plateform. The ore-forming geological condition and the development of geochemical anomalies are favorable. The deposit is mainly hosted in the rhyolite, rhylite porphyry and rhyolite breccia acid volcanic rocks of lower cretaceous Bainvyangpan Formation(K1bn). The deposit is clearly controlled by fractures and fault structure is well-developed in the mine area, providing sufficient tectonic conditions for the later mineralization. Affected by magmation and tectonic influence, silicification, pyritization and sericite-quartz alteration are well developed. In this dissertation, the soil geochemical survey data and geological mineral resources data were combined and MAPGIS was applied to evaluate comprehensive information ore-prospecting orientation prediction.Based on the study of previous evaluation methodology, Successive sweep method and factor analysis were used to mark the various single element anomalies and element association anomalies. Geological characteristics of deposit and geochemical anomaly characteristics of water-laid deposits were summarized to established the ore-forming geological conceptual model. Then metallogenic theory of energy was introduced to mark the comprehensive element anomalies. On the basis of that, multi geo-science information were transferred to MAPGIS layer files and then corresponding attribute database was establish. By the means of spatial analysis technology, mineralization contribution of muti geo-science information were analyzed and geological variables of favorable mineralization were extracted. With 100 m by 100 m grid as geological statistics unit, correlation and coupling of multi geo-science information statistically analyzed, based on which, comprehensive quantitative information model and calculation of mini grid cell information score were made to gain comprehensive information evaluation quantitative classification figure,and made out five prospecting target. Evidence weighting method is adopted to predict comprehensive information. Ore output parts with comprehensive information were selected as control zone, taking good indicator for deposit as their evidence factors. The weight coefficient of each evidence was calculated, and then the metallogenic posterior probability of each predictable unit were gained, finally, posterior probability classification figure were made and four prospecting target were delineated.Comparing with the results which is the situation of element combination anomaly of the two methods, the accuracy results of evidence weighting method is poor. Because of the Smaller study area and the lack of statistical information, the statistical results is bad and the metallogenic prediction effect is not ideal. The comprehensive information quantitative method which weakens the control factors of ore body size and strengthens the control factors of all kinds of favorable ore-prospecting criteria can conclude the more accurate prediction results.