View article

A systematic study of mineral compositions has been carried out on stratigraphic sections through the Panzhihua intrusion, a layered gabbroic sill of late Permian age that hosts significant magmatic Fe–Ti–V oxide deposits in the Emeishan large igneous province, SW China. The intrusion, which is ∼19 km long and ∼2 km thick, is divided into a Marginal zone (MGZ), Lower zone (LZ), Middle zone (sub-zones MZa and MZb) and Upper zone (UZ) from the base upwards. Compositions of the most primitive cumulus olivine (Fo₈₁) and plagioclase (An₇₃) found in the intrusion suggest that the parental magma was similar to the Mg-rich end-member of the coeval high-Ti basalts in the region. Two reversals in terms of mineral compositions are found in the intrusion, one in the lower MZa and the other at the transition between the MZb and the UZ. The first reversal is marked by a gradual increase in the An content of …