Abstract
High-pressure liquid chromatographic traces of petroporphyrins can be compared on the basis of areas under selected peaks. Principal components analysis of such data obtained from a suite of twelve crude oils (McKittrick Field, California; Tertiary age) shows inter-sample relationships similar to those observed in a multivariate statistical analysis of published hydrocarbon distributions in the oils. Both groups of compounds appear to reflect the operation of processes in the geologic environment which have been inferred elsewhere to be migration and maturation.