Craton

A stable continental crust is the end product of “intense magmatic, tectonic, and metamorphic forces and consists of metamorphosed crystalline and metamorphic rocks.” Typically, this is lightweight, igneous rock, such as granite (American Geophysical Union, Spring Meeting 2004).

As my artist brain understands it, there were less heavy metals and more light silica in this type of magma, allowing it to “float” and cool, rather than sink back down to the molten core of the earth. Under these tremendous forces, pre-continents, or cratons, formed. There are 35 cratons, which probably came from larger “supercratons” that were broken up over time. Every continent has a craton; the largest is in North America.