Extrusive rock Extrusive rock Extrusive rock refers to the mode of igneous volcanic rock formation in which hot magma from inside the Earth flows out (extrudes) onto the surface as lava or explodes violently into the atmosphere to fall back as pyroclastics or tuff.This is as opposed to intrusive rock formation, in which magma does not reach the surface. The main effect of extrusion is that the magma can cool much more quickly in the open air or under seawater, and there is little time for the growth of crystals. Sometimes, a residual portion of the matrix fails to crystallize at all,
Magma (comics) rock from the Earth's core, producing projectiles composed of lava, or miniature volcanoes. When using her powers, Magma typically assumes an energized form that emits intense light and heat. She can also create orbs of a fire-like substance and use them as projectiles or a source of light. Although Magma has triggered small earth tremors without taking on her energized form, she has never been seen to use her power to control lava while in her ordinary human appearance. On M-Day, she traveled within the heated gases of an active volcano, and demonstrates an immunity to volcanic gases, heat, and