RStudio scripts for modelling AFC in arc magmas

This document is linked to the following publication: Chiaradia, M. (2025) Crustal assimilation in arc magmas controlled by overriding plate thickness. Frontiers in Earth Science 13:1690397; doi: 10.3389/feart.2025.1690397. It contains five RStudio scripts. The first one is to determine Nd and Sr isotope outliers from the data based on the quantile method (lower and upper boundaries of 0.01 and 0.99). The second one is to determine outliers in the regressions in the 143Nd/144Nd-Co, 143Nd/144Nd-MgO, 87Sr/86Sr-Co, 87Sr/86Sr-MgO spaces through the robust regression Bisquare Weighting method. RStudio scripts 3-5 are used to model AFC processes in arcs of different thicknesses in the 143Nd/144Nd-Co space with a Monte Carlo approach. The AFC equations used are from DePaolo, D. J. (1981). Trace element and isotopic effects of combined wallrock assimilation and fractional crystallization. Earth and Planetary Science Letters, 53(2), 189–202. https://doi.org/10.1016/0012-821X(81)90153-9. Successful simulations of the model for thin, thick and very thick arcs are plotted in the 143Nd/144Nd-Co space and in the 143Nd/144Nd of the assimilant versus r space where r is the assimilation rate = [mass of the assimilant] / [the mass of crystallized melt].