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.
Igneous Rocks are formed by the cooling and crystallization of a silicate melt (dominated by oxygen and silicon, with a variety of other metals). The occurrence and distribution of igneous rocks and igneous rocks types can be related to the operation of plate tectonics. The molten rock material from which igneous rocks form is called magma.