Application Study Of Overlap Analysis In Metallogenic Prognosis

Overlap analysis is a method of metallogenic prognosis. That is based on Metallogenic Prognosis theory. There are some ideas of homoplasy analogy theory and some working process of all-around information theory in the method.Overlap analysis is a new method of metallogenic prognosis that is based on GIS (Geographic Information System). By a studying, the author thinks that overlap analysis is a facile and effective method of metallogenic prognosis. This method roots in a practical project of metallogenic prognosis.There are six steps in the overlap analysis. They are to integrate data, to find the major factors, to find the overlap anomaly, to study the rule of overlap anomaly, to determine target for prospecting, and to check-up target.In the project of metallogenic prognosis in Yangjiazhangzhi ore field and its periphery, the major factors are geochemical anomalies. They found tow new deposits in one target for prospecting. In the project of studying lead and zinc resource potential in Liaohe group, the major factors are lead geochemical anomaly, zinc geochemical anomaly and Liaohe group. There were17targets for prospecting to be determined. They checked up3targets, and they found important significative geochemical anomalies in these targets. In the project of1/50000geochemical survey, they used overlap analysis as tools. They picked up about1000km2as workaround from100000km2region of interest. By work, they determined13targets for prospecting in the workaround. And then, they found ore band in one target that they checked up one. In the project of studying iron ore resource potential in Anshan region, the major factors are positive value zones of vertical quadratic derivative of aeromagnetic anomaly and bouguer anomaly. According to the results of overlap analysis, they thought that there are lots of iron ore resource in that region. Especially, there are lots of iron ore resource under the quaternary.By this studying, the author thinks that overlap analysis is a facile and effective method of metallogenic prognosis. It can be used in all project of metallogenic prognosis. Along with this method will be used in more projects of metallogenic prognosis, overlap analysis will promote theory advancement of metallogenic prognosis.