Effect of matrix correction model and mass attenuation coefficients in EPMA-CHIME dating

Abstract

Effect of chosen matrix correction model and physical parameters in CHIME (Chemical U-Th-total Pb Isochron Method) has been evaluated using reference monazite (NMQL by Knoper, 2000 and 44069 by Aleinikoff et al., 2006). Evaluated matrix correction models are: conventional ZAF, surface-center Gaussian by Armstrong (1991), PAP, XPP and XPhi. PAP, XPhi and XPP yield small systematic error (less than 1%) while other models give systematically older ages.