ROLE OF SOME STATISTICAL AND MATHEMATICAL METHODS IN INTERPRETATION OF REGIONAL GEOCHEMICAL DATA

Interpretation of regional geochemical survey data requires consideration of the effects of bedrock geochemistry and the influence of weathering and other secondary factors tending to modify the bedrock-soil-stream sediment relationship. Visual interpretation of complex multi-element data may only serve to recognize the more obvious geochemical patterns leaving subtle though significant features undetected. In areas of simple geochemistry exemplified by the Basement Complex of Sierra Leone, trend surface and rolling mean analysis can be used to portray trends in metal distribution and to focus attention on local areas where the data deviate significantly from the trend. Similarly, in areas of complex geology and geochemistry, factor-vector analysis is applicable as a method of determining and delineating patterns of variation in the trace element composition as a whole which may then be correlated with the geology, secondary environment or some other causal factor. © 1969 Society of Economic Geologists, Inc.