Chorea is an abnormal involuntary movement disorder, one of a group of neurological disorders called dyskinesias. The term chorea is derived from the Ancient Greek: ÏÎ¿ÏÎµÎ¯Î±, as the quick movements of the feet or hands are comparable to dancing. The term hemichorea refers to chorea of one side of the body, such as chorea of one arm but not both.
Metamorphic rocks are most likely found at a site that is  deep under ground. Metamorphic rocks are formed by other materials  under great amounts of pressure. This pressureâ¦ is caused by plate  collisions in the lithosphere.
Lesson: Igneous rocks are formed when the magma from a volcano cools-. Sedimentary rocks form when eroded earth and other materials settle in layers. These layers press down over time to form solid rock. Metamorphic rocks are igneous or sedimentary rocks that have been changed by high temperatures or extreme pressure.