Definition of marriage. 1  1a see usage paragraph below : the state of being united as spouses in a consensual and contractual relationship recognized by lawb : the mutual relation of married persons : wedlockc : the institution whereby individuals are joined in a marriage.
The majority of the surface rocks on the North American continent are sedimentary. The mountainous regions of the west and southwest are made of igneous rocks. The Appalachian Mountain region of the eastern U.S. and most of eastern Canada are made of metamorphic rocks.
When most people think about igneous rocks they envision a volcano erupting pumice and lava. The term igneous comes to us from the Latin word  Ignis  which means fire. Igneous rocks are produced this way but most igneous rocks are produced deep underground by the cooling and hardening of magma.Magma is molten (melted) rock under the surface of the Earth. It is produced in the upper reaches of the mantle or in the lowest areas of the crust usually at a depth of 50 to 200 kilometers.hen 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.