Variation coefficient between the front and back analysis data calculated using the following formula: (D/¹⁸O_(front) )/( D/¹⁸O_(back)). (a) Olivine. (b) Pyroxene. (c) Plagioclase. Both the front and back data exhibited a diffusion feature that increased with depth. Thus, the variation trend of the coefficient follows an exponential function. For olivine, pyroxene, and plagioclase, three distinct calibration curves were produced through exponential fitting. Utilising these three sets of equations allows for the effective removal of influence of D particle re-deposition during the deep NanoSIMS analysis from the original D/¹⁶O data.