The Characteristics Of Soil Geochemistry And The Preliminary Prediction Of Metallogenic Potential Of Bayanaobao Area In Inner Mongolia

The Bayanaobao area in Inner Mongolia is located in the Erlian-Dongwuqi metallogenic belt in the Paleo-Asian Ocean tectonic domain. It is the most important polymetallic deposits producing area in northern China and Outer Mongolia with good metallogenic background. The main structures of this area are north-west trending faults. The joints are less developed and the folds are not obvious.The lithologies of the research area are mainly fine grained biotite adamellite, medium to fine-grained porphyritic biotite monzonitic granite, medium to fine-grained granodiorite and granite-porphyry. The strata are mainly Upper Devonian sandy slates in Angeeryinwula Formation and Lower Cretaceous sandy conglomerates in Damoguaihe Formation. The mineralization and alteration are well developed in the contact zone between the Upper Devonian sandy slates in Angeeryinwula Formation and Middle Jurassic intrusions, which are presented as silicification, limonitization, greisenization and hornfels etc.The working methods of soil geochemistry survey were summarized, and the distributions of elements in the soil were analyzed. Element anomaly threshold is computed by iterative method, geological software(Mapgis6.7?sufer8.0) were used to draw the map of geochemistry anomaly, lots of anomaly areas were delineated.Based on the 1:5 million scale soil geochemistry survey, combined with regional geological features and geological survey, the following understanding and results are obtained:1) There is a close relationship between the structure and the ore formation. The fault is the magma migration channel in this region. The endogenetic deposit is mainly composed of hydrothermal mineral resources. The ore fluid circulation channel and the ore hosting space are closely related to the structure. The ore veins or ore bodies are hosted in the NW trending extensional fractures subordinated to the NE trending fracture.2) Using multivariate statistical methods of correlation analysis, cluster analysis and factor analysis, three prospecting indicator elements were determined: 1.Ag-Pb-Cd-Zn-Hg-Sn; 2.Cu-Ni-Y1-Li-Nb; 3.As-Bi-Mo-W. Based on the combination of anomaly evaluation three B3 combination anomalies were delineated.3) Mineralization is mainly concentrated in the southwest region. According to the geochemical anomalies and geological characteristics of the surveying area, the metallogenic prediction of the survey area are delineated a in a measuring region in southwestern area a target. It is speculated that the predicted prediction of the target region may be related to the hydrothermal activity.