The extraction of regional geochemical element composite anomalies in northern Sanjiang region and its prospecting significance

As geochemical elements carry some mineralization information, geochemical anomalies of elements can frequently serve as prospecting criteria. With the deep development of exploration geochemistry, the geochemical anomaly evaluation has become the focus of the attention. Using the 1∶200 000 geochemical data of northern Sanjiang region, the authors determined indicator elements composite anomalies of different mineralization types through the R type factor analysis. On the basis of the factor scores as comprehensive indices，the universal kriging residual value was applied to delineate geochemical anomalies．The results show that there exist two types of element assemblages，i.e．，the Ag-Zn-Pb-Sb-Bi element assemblage associated with hydrothermal Ag and Pb-Zn sulfide deposits, and the Mo-Cu element assemblage associated with porphyry Mo deposits．These two types of composite anomalies are consistent with the known deposits in spatial distribution．It is shown that this method can reveal the regularity governing the close relationship between composite anomalies of geochemical elements and mineralization types, thus providing new information for mineral prospecting in northern Sanjiang region．