MnO-TiO2-P2O5: Petrotectonic Environments, Mullen

A ternary diagram using MnO, TiO2, P2O5 can discriminate between five petrotectonic environments of basaltic rocks (45–54% SiO2). Fields for mid-ocean ridge, island arc tholeiite, island arc calc-alkaline, ocean island tholeiite, and ocean island alkalic rocks were distinguished on the basis of 507 analyses from well-defined environments.

Ellen D. Mullen MnO/TiO2/P2O5: a minor element discriminant for basaltic rocks of oceanic environments and its implications for petrogenesis , 1983 [ref]

require('ggtern');
 
classifydiag.basalts_mullen <- function (wtp_data, ...)
{  
ds <- selectNames(wtp_data,c('Name','TiO2_wtp','MnO_wtp','P2O5_wtp'))
 
pts <- data.frame(Name=ds$Name,
                  X = ds$MnO_wtp*10,
                  Y = ds$TiO2_wtp,
                  Z = ds$P2O5_wtp*10);
 
labels <- c("MnO_wtp*10", "TiO2_wtp", "P2O5_wtp*10");
 
lines <- data.frame(X1 = c(0.61, 0.61, 0.41, 0.41, 0.25, 0.30, 0.30),
                    Y1 = c(0.39, 0.18, 0.59, 0.27, 0.68, 0.30, 0.30),
                    Z1 = c(0.00, 0.21, 0.00, 0.32, 0.07, 0.40, 0.40),
                    X2 = c(0.61, 0.22, 0.41, 0.28, 0.30, 0.06, 0.08),
                    Y2 = c(0.18, 0.18, 0.27, 0.27, 0.30, 0.42, 0.00),
                    Z2 = c(0.21, 0.61, 0.32, 0.45, 0.40, 0.53, 0.92));
 
marks  <- data.frame(Label=c("OIT", "MORB", "IAT", "OIA", "CAB"),
                     X=c(0.17, 0.33, 0.52, 0.16, 0.50),
                     Y=c(0.60, 0.50, 0.30, 0.25, 0.10),
                     Z=c(0.23, 0.17, 0.18, 0.59, 0.40));
ret <- c();
ret$type <- "ternogram";
ret$points <- pts;
ret$labels  <- labels;
ret$lines <- lines;
ret$marks <- marks;
 
return(ret);
}