Extrusive rock instead becoming a natural glass or obsidian. If the magma contains abundant volatile components which are released as free gas, then it may cool with large or small vesicles (bubble-shaped cavities) such as in pumice, scoria, or vesicular basalt. Examples of extrusive rocks include basalt, rhyolite, andesite, obsidian and pumice. 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
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