Major elements EMPA method for silicate

The chemical composition of the selected minerals (e.g. olivine, orthopyroxene, clinopyroxene, spinel, amphibole and phlogopite) in the peridotite and pyroxenite was analyzed by a JEOL JXA–8230 electron probe micro analyzer (EPMA) under the condition of 10 nA electric current, 15 kV accelerating voltage and 2 um beam diameters at the State Key Laboratory of Continental Dynamics, Northwest University, China. The standard materials for each element were listed as follows: diopside for Ca, rutile for Ti, magnetite for Fe, rhodonite for Mn, chromium oxide for Cr, jadeite for Na, almandine for Al, olivine for Mg and Si, SrO for Sr, and NiSi for Ni.