Abstract
Spurious trends in Pearce-type ratio variation diagrams are constrained to go through the origin and the average composition of the data set. A valid trend has a significant (nonzero) y-intercept and a meaningful slope. The two types of trends are thus easily distinguished. Numerical simulation is a useful, perhaps even necessary, method of checking the effects of random variations. Calculations of probability suggest that the odds against purely random data mimicking an olivine trend in komatiites are great — perhaps as much as 100 00 0000 to 1. That such original igneous trends are descernible through the veil of metamorphic overprinting is a powerful demonstration of the usefulness of this technique.
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Pearce, T.H. The identification and assessment of spurious trends in Pearce-type ratio variation diagrams: a discussion of some statistical arguments. Contr. Mineral. and Petrol. 97, 529–534 (1987). https://doi.org/10.1007/BF00375331
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DOI: https://doi.org/10.1007/BF00375331