Magmatic processes inferred from chemical composition, texture and crystal size distribution of the Heikongshan lavas in the Tengchong volcanic field, SW China

► The Heikongshan lavas comprise five flow units associated with three episodes of eruption since mid-Pleistocene. ► The lavas are grouped into basaltic trachyandesite, trachyandesite, and trachyte based on chemical composition and texture. ► These lava groups reflect the changes of physical environment through time in the magma chamber. ► Magmatic evolution was mainly related to the fractional crystallization of pyroxene and plagioclase. ► The concave-up plagioclase CSD curves of different lava units are results of magma mixing.