Study On Multi-source Information Metallogenic Prognosis Of Iron Using GIS

With the rapidly development of our economy, more and more mineral resources are needed inour country. However, mineral resources are dwindling by the continuous mining. The contradictionbetween supply and demand of iron ore resources is increasingly serious. As a result, it has putforward higher requirements to protecting the mineral resources. Since the uncertainty and lowaccuracy, prospecting in traditional ways with single information have been unable to meet therequirements and been gradually replaced by comprehensive prospecting technology withmulti-source information, which means using multi-source geo-information such as geology,geophysical prospecting, geochemical exploration, remote sensing and the theory of geologicalanomalies to carry out mineral exploration quickly and work on ore prediction accurately andeffectively.In this paper, middle region of Langlingzaohuo in qinghai province is regarded as the researcharea where skarn-type iron ore is taken as target minerals. Based on the GIS technology,information extraction analysis and integration are carried out on the multi-source geologicalinformation including geology, mineral resources, geophysical prospecting, geochemicalexploration and remote sensing to determine the ore-prospecting signs, establish prospectingprediction model, and finally select the target prospecting areas using evidence weight method.The following matters were reviewed and sytematically analysised in this paper.1. From the existing data of geology and mineral resources, this paper analyzes the formationstructure and magmatic rocks which is closely related to ore-forming elements, combining with themineral distribution the regional metallogenic regularity has been summarized, and theore-prospecting signs have been determined. At last, comprehensive prospecting model ofskarn-type iron ore in research area has also been built.2. This paper disposes the geophysical, geochemical, remote sensing data of the research areawhere take the ETM+remote sensing alteration information as priority. It has improved the classicCrosta method by combining different bands, which can enhance alteration information in lowvegetation zones. Therefore, It is more suitable for extracting the remote sensing alterationinformation in the study area.3. Based on MAPGIS, the multi-source information including geology, mineral, geophysical,geochemical and remote sensing are processed digitally whose formats are unified, then a spatial database with multi-source geological data in the study area is established. Combined with the ironprospecting model, this research extracts the factors of multi-source geological informationassociated with mineralization using GIS spatial analysis and correlation statistical method.4. It builds a prediction model of the evidence weighting method on the basis of comprehensiveprospecting model and the multi-source evidence factors. According to the principle of selectingtarget mineral zone, combining with map of posterior probability in study area, this paper delineates2metallogenetic prospective areas in A level,3metallogenetic prospective areas in B level and2metallogenetic prospective areas in C level. The predicted results have important guidingsignificance to further exploration in the area.In this paper, the information of different sources and different scales are synthesing andoptimizating rapidly and effectively by GIS, and represented in qualitative and quantitative way tomake the predicting results more intuitive and reliable, which provides theoretical and practicalguidance for further ore prospection in the area.