Use of magnetic susceptibility, density, and modal mineral data as a guide to the composition of granitic plutons

Journal of the International Association for Mathematical Geology - 1993
James H. Bourne1
1Department des Sciences de la Terre, Université du Québec à Montréal, Montréal, Canada

Tóm tắt

Magnetic susceptibility, density, modal mineral, and whole rock geochemical data have been collected from two granitic plutons in Quebec. Each of the first three variables is correlated with SiO2 to some degree. Multiple regression using all three variables simultaneously as independent variables and SiO2 as a dependent variable yielded pluton dependent equations which were then used to calculate SiO2 values for each analysis. Calculated values of SiO2 typically differ from the analysed values by 1.5% for the first pluton and 1.0% for the second. The polynomials thus can be used to estimate the SiO2 value of unanalyzed samples with some confidence. Plots of calculated SiO2 reveal details of chemical variation with the pluton which were not observed when using chemical data alone due to the small number of analyzed rocks. The method also provides an independent evaluation of possible analytical errors.

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Journal of the International Association for Mathematical Geology

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