Geochemistry and metallogeny of the 259 Ma Emeishan Large Igneous Province (SW China)

Abstract

The Emeishan Large Igneous Province (ELIP) in Southwest China covers the western part of the Yangzte Block and the eastern part of the Tibet Plateau and comprises the Emeishan Continental Flood Basalts (ECFB) and mafic layered intrusions. The ELIP has an exposed area of more than 5x105 km2 and was dated at 259 Ma, 8 Ma earlier than the P/T boundary. The eruption of the ECFB had a close link with the end-Guadalupian mass extinction The volcanic sequence has variable thickness ranging from less than 200 m in the northeastern part to 5000 m in the southwestern part. Geochemical data show that the volcanic rocks have derived from a lithospheric mantle previously contaminated by recycled crustal materials. There are two different types of magmatic deposits associated with the ELIP: V-Ti magnetite deposits and magmatic Ni-Cu (PGE) sulfide deposit. Several giant V-Ti bearing magnetite deposits are hosted in large layered intrusions, whereas Noril’sk-type magmatic Ni-Cu (PGE) sulfide deposits are associated with sub-volcanic sills.