关键词: 峨眉山大火成岩省, 苦橄岩, 含水量

Abstract: Large igneous provinces (LIPs) represent melting anomalies of the Earth. Recent investigations of water content of the
primary magma in the global LIPs show that source hydration had played an important role in their genesis. The Emeishan LIP is one of
Permian LIPs in the world. Previous work on the Dali picrites, within the initial stage of eruption, indicates that water largely promoted
partial melting of mantle. However, whether water played a significant role in other stages of eruption is not clear, which is critical to
understand the genesis model of LIPs. Here, we report water content of the picrites from Binchuan, within the upper part of eruption
sequences of ELIP. The result shows that the primary magma could have water content as high as 2.8 wt.%, slightly lower than that of
Dali picrites, but still considerably higher than that of MORB and OIB. Combined with the previous work, this study shows that mantle
hydration would be essential for the whole eruption of ELIP.

Key words: Emeishan Large Igneous Province, picrites, water content