The Emeishan Basalt is distributed in the southwestern part of China. Based on the tectonic setting and petrochemistry

it can be divided into three petrobelts

i. e. the western

central and eastern

with the Jingho-Bingchun and Ganlo-Kunming abyssal fracture zones roughly being the boundaries between them.

The samples studied in this paper were collected from the representative sections of the petrobelts described above

Rare earths (REE)

transition metals (TME) and large ion lithophile elements (LILE) were determined by instrumental neutron activation analysis. The abundances of LILE intermediate between those of continental tholeiites and alkali basalts. The REE patterns of the basalt samples are LREE enriched type

the degree of enrichment varies with the sampling locations. The more west the sampling location

the less enriched the degree is. Based on the (Ce/Yb)

CN

Vs. Ce

CN

plot

it can be inferred that the basalts in the central and eastern petrobelts might be formed through about 5% partial melting of garnet lherzolite while those in the western petrobelt might be due to about 10% partial melting. According to the La/Sm-La figure

it was shown that the formation of the basalt from the western petrobelt was significantly controlled by the degree of partial melting and that fractional crystallization had played an important role in the petrogenesis of the central and eastern petrobelts.