Negative correlations between (Rh/Ru)_n, (Pt/Ru)_n, (Pd/Ru)_n and Mg-number in the Emeishan flood basalts indicate that Rh, Pt and Pd behave incompatibly during magma differentiation.

The incompatible behavior of Rh is also supported by the fact that (Pt/Rh)_n remains constant with decreasing Mg-number in the lavas.

Low (Nb/Th)_n and ε_Nd in the lavas that are depleted in Pt–Pd support the notion that crustal contamination is essential for inducing sulfide saturation in basaltic magma.

An Ir-depleted, fertile lherzolite source mantle in northern Vietnam is inferred from Ir depletion in picrites with high Al₂O₃/TiO₂ from this region.