Study Of Data Processing Method In Regional Geochemical Exploration

Data processing is an important step of regional geochemical exploration, which aims not only to provide data processing and maps, but also to fully extract the information contained in the data, and serve for geological prospecting and other applications related disciplines. For nearly five decades, with the development of applied mathematics, statistics and computer technology, new methods of data processing have been applied. The levels of prospecting and forecasting have been greatly improved.First of all geochemical data processing related to the problem of building up geochemical background model, then the extraction and integration of single element anomaly information, and then is multi-element anomaly information extraction and integration of comprehensive, finally, the application of integrated information prospecting target, assessment of resource potential.The study area is located in the east side of middle Daxinganling Mountain, north side of Inner Mongolia central geosyncline fold, which is favorable for mineralization. In the east anomaly range, surface sampling and trenching sampling analysis showed a result of copper, molybdenum, silver coexist. Content of copper is up to 1.66%, accompanying silver is up to 144g / t, molybdenum is up to 0.044%, respectively reached the industrial grade and critical grade, which shows a favorable multi-metal ore deposit. Therefore, whether the anomaly is effectively determined is an important symbol to measure different methods of data-processing.At first, this study used the directly calculate method to process the date, which based on the assumption of normal distribution. It is considered when the data were normally distributed and non-normal distributed when processing. Moving average method is commonly used in practical work. At this study, moving average method got a result very approaching to the ones with directly calculate method. This shows that in the framework of small scale, when the case of geological background is simple, the directly calculate method and moving average method can be both used for delineation of geochemical background and anomalies.Correlation analysis showed that there are broad and complex relevance between the 14 elements in the study area. Cu and the other 12 elements in significant positive correlation, indicating that the 13 elements can be used as instructions to find the elements Cu mine.R-mode cluster analysis, R-mode factor analysis results showed that Cu is most related to Pb, Zn, Ag, Bi and Sn. This could serve as a basic indicator for multi variate data processing.R-mode factor analysis results show that there are two Cu-related indicating elements aggregation. One is F2 (Sn, Zn, Pb, Cu, Ag, Hg) aggregation, and the other is F5 (Bi, Ag, Pb, Cu, Zn) aggregation. There are corresponding anomalies exist at the known deposit. The 13 elements Mahalanobis distance abnormal of Cu, Au, Ag, Pb, Zn, Mo, W, Sn, As, Sb, Bi, Nb, and Y is large-scale, while the six elements Mahalanobis distance abnormal is smaller, and the abnormal distribution is more obvious. These reflect the known deposit favorably.The anomaly score of Cu, Au, Ag, Pb, Zn, Mo, W, Sn, As, Sb, Bi, Nb, Y and the anomaly score of Cu, Pb, Zn, Ag, Bi, Sn identified the anomalies match the known deposit, the anomaly scale is large and data processing is simple.The artificial neural network methods using Cu, As, Bi, Sn, Y, Mo got a result similar with anomaly score method and Mahalanobis distance method. There are three large-scale anomalies at northern study area, and also a large anomaly in southern area.In short, single-element anomalies can reflect the specific location of outliers more accurately, but a single anomaly is of small size and more scattered, the direction of the spatial distribution was not obvious. Multi element geochemical anomaly is of large scale, anomalies may be drifting. But the order is more obvious. It is possible that ore-controlling structure is conducive to a comprehensive analysis and evaluation of anomalies.According to single element and multi-variate geochemical anomaly comprehensive analysis, the number 1 anomaly is favorable for Cu- polymetallic deposit prospecting.