Definitions for "Phreatomagmatic"
A style of volcanic eruption that takes place when the rising magma contacts shallow groundwater, or erupts under shallow oceanwater or lakes. The water and magma mix and generate strong steam explosions that blast apart the magma (and any preexisting rock) into fine-grained material. The resulting deposits form distinctive structures called tuff rings or tuff cones.
An explosive volcanic eruption that results from the interaction of surface or subsurface water and magma.
involving both gases and magma