Canada, United States, and Mexico
A. Thucydides
Thucydides was an Athenian historian and general.
EXTRUSIVE IGNEOUS ROCK
When lava reaches the surface of the Earth through volcanoes or through great fissures the rocks that are formed from the lava cooling and hardening are called extrusive igneous rocks. Some of the more common types of extrusive igneous rocks are lava rocks, cinders, pumice, obsidian , and volcanic ash and dust.
<span>Foliated rocks show different minerals or grains that have been segregated into layers or aligned nonrandomly. Quartzite is an example of a nonfoliated metaphoric rock. The main factor that changes rocks during contact metamorphism is both heat and pressure, but if had to choose one I would select pressure. When shale undergoes metamorphism it becomes slate!</span>
