PT  - JOURNAL ARTICLE
AU  - Jeffrey Shragge
AU  - Cameron A. Snow
TI  - Bayesian Geochemical Discrimination of Mafic Volcanic Rocks
AID  - 10.2475/ajs.306.3.191
DP  - 2006 Mar 01
TA  - American Journal of Science
PG  - 191--209
VI  - 306
IP  - 3
4099  - http://www.ajsonline.org/content/306/3/191.short
4100  - http://www.ajsonline.org/content/306/3/191.full
SO  - Am J Sci2006 Mar 01; 306
AB  - Determining the original tectonic setting of volcanic rocks via their geochemical signature has been a long-standing goal for petrologists. However, current visually based methods for geochemical discrimination afford only limited success. We develop a probabilistic method for geochemical discrimination based upon statistics generated from geochemical databases and Bayesian analysis. This method incorporates elemental covariance, accounts for data measurement and theoretical uncertainty, and is not restricted in dimensionality of analysis, which is inherent in visual systems of discrimination. Furthermore, the method provides a direct way to discern statistical outliers whose inclusion would otherwise lead to lower discrimination accuracy. Tests of the approach yielded successful classification rates for single analyses of over 90 percent for volcanic arc basalts, mid-ocean ridge basalts, and ocean island basalts.