Chapter 1
Interpretation and Display of Surface Geochemical Data

Ronald W. Klusman
Department of Chemistry and Geochemistry, Colorado School of Mines
Golden, Colorado, U.S.A.

ABSTRACT

A review of the methodology for interpretation and display of surface geochemical data is presented, and a discussion of direct and indirect methods for surface geochemistry is reviewed. The interpretation of surface geochemical data must initially focus on determining what is background, and which may be anomalous samples. The use of histograms and probability plots for this separation is illustrated. Because surface geochemical data are inherently noisy, a variety of smoothing techniques is used, including moving means for line plots and moving cell means for grid data. Adequacy of sampling density is assessed using an analysis of variance method. The data must be consistent with the geological evaluation and must aid in the assessment of petroleum potential, as well as being statistically significant.