# www/chnosz/Fe-O-S-H.R
# diagram for front page of CHNOSZ website,
# after Yang et al. (2018)  20180126
png("Fe-O-H-S.png", width = 350, height = 350)
par(cex = 1.4)
# use the SUPCRT92 instead of Berman versions of hematite and magnetite;
# affects the position of the hematite-magnetite reaction 20190422
add.obigt("SUPCRT92")
basis(c("Fe", "H2", "H2S", "H2O"), c("cr", "aq", "aq", "liq"))
species(c("hematite", "pyrite", "pyrrhotite", "magnetite"))
a <- affinity(H2S = c(-4, -1.5, 400), H2 = c(-6, -1, 400), T = 300, P = 700)
diagram(a, fill = "terrain", mar = c(3, 3, 2, 1), yline = 1.5)
title(main = "Fe-O-H-S", cex.main = 0.95) 
legend("bottomright", legend=c("300 \u00b0C, 700 bar"), cex = 0.9)
thermo.axis()
# reset the database
obigt()
dev.off()