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.
Metamorphic rocks are actually products of rocks that have undergone changes. Thus, a metamorphic rock may have originally been an igneous, sedimentary, or even another metamorphic rock. The changes occur when the original rocks are subjected to extreme heat and pressure beneath the Earthâs surface.ome examples of igneous rocks are granite, scoria, pumice, and obsidian. Pumice, for instance, is formed when lava made up of melted rock, water, and trapped gas is ejected from a volcano during a violent eruption.