Numerical transformations in geochemical data: objectives, philosophy, and methods to improve information extraction and data presentation

摘要

Concentration data derived from geochemical surveys are commonly evaluated using numerical techniques designed to facilitate data interpretation. Numerical transformations are sometimes used to impart new characteristics to the data that facilitate evaluation. Historically, geochemical data have been transformed for three reasons; these cause the transformed result to: (l) exhibit a 'normal' or 'nearly normal' distribution so that statistical techniques requiring normality assumptions can be applied, (2) exhibit a measurement error that is constant across the range of the data so that data evaluation is undertaken on a level playing field', or (3) exhibit the maximum geochemical contrast (variance) within the data so that all of the information contained therein can be recognized.