ABSTRACT
The lognormal distribution has long been recognized as a useful model in the evaluation of geological variables whose value distribution is often extremely skew. Statisticians have long been strongly motivated to develop improved methods to analyze geological variables. When studying statistical applications in geology, one should be aware of the difference between the statistical definition of a sample and the corresponding geological definition. The significance of the lognormal distribution in the evaluation of geologic data was brought to light by H. S. Sichel. The most complex applications of lognormal theory in geological sciences can arguably be found in the evaluation of mineral deposits. The correlation between sample values and block values is indicative of a more basic autocorrelation between sample values. The lognormal distribution has continuously played a very significant role in the study of geological data. A practical problem remains that the lognormal model is often only an approximation of the true distribution of geological data.
