sentences:  The town owes its existence mainly to two ore bodies that formed about 1.75 billion years ago along a ring fault in the caldera of an undersea volcano.Tectonic plate movements, plate collisions, uplift, deposition, erosion, and other geologic processes eventually exposed the tip of one of the ore bodies and pushed the other close to the surface, both near Jerome.In the late 19th century, the United Verde Mine, developed by William A. Clark, extracted ore bearing copper, gold, silver, and other metals from the larger of the two.