The Mafic–Ultramafic Dykes in the Yanbian Terrane (Sichuan Province, SW China): Record of Magma Differentiation and Emplacement in the Emeishan Large Igneous Province

Numerous olivine-rich dykes intruded the late Proterozoic Yanbian terrane, Sichuan, SW China. The dykes are less than 10 m thick and show thin aphanitic chilled margins (c. 10–20 cm wide), whereas most of the dyke volume comprises coarse porphyric rocks made up of olivine grains up to 2 cm in size set in a groundmass consisting of clinopyroxene, plagioclase, Fe–Ti oxides, a second generation of olivine, hornblende and biotite. Chrome-spinel...