Evaluation of Lindsley's pyroxene thermometer for chondrites: Regression equations and correction for minor elements

Abstract

The vales of Wo and Fs components were read along isotherms on the quadrilateral diagram of pyroxene at 1 atom presented by Lindsley (1983), fifty points for each OPx and CPx region. Regression equations of temperature for CPx and OPx are as follows: T(CPx) = 860.9 - 1.548*Wo^2 + 70.55*Wo + 0.3166*Fs^2 – 23.51*Fs, T(OPx) = 601.9 – 14.60*Wo^2 + 227.3*Wo – 0.1587*Fs^2 – 1.708*Fs. Multiple correlation coefficients and standard errors are 0.998 and 10.1 °C for CPx and 0.998 and 11.5 °C for OPx. In order to determine Wo and Fs components of CPx, correction for kosmochlor (NaCrSi₂O₆) is also proposed.