Answer: Heidi Doody. Heidi Doody was built by Margo Rose and had the voice of Norma MacMillan and Donna Miller. Heidi was introduced as a stranger who saved Buffalo Bob's life in Africa. Later, Heidi was adopted and became Howdy's sister.
The descending of rock layers at subduction zones causes metamorphism in two ways; the shearing effect of the plates sliding past each other causes the rocks coming in contact with the descending rocks to change. Some of the descending rock will melt because of this friction.
Metamorphism can be instantaneous as in the shearing of rocks at plate boundaries or can take millions of years as in the slow cooling of magma buried deep under the surface of the Earth. There are three ways that metamorphic rocks can form.