When a craton is exposed at earth's surface, it is called a when a craton is exposed at earth's surface, it is called a caldera continental shield mid-ocean ridge plate transform fault region?

When a Craton is exposed at earth's surface, it is called a continental shield. Continental shield is any of the large stable areas of low relief in the Earth's crust that are composed of Precambrian Crystalline rocks. Shield areas are regarded as continental nuclei, the observation often being made that most continental shields are bordered by belts of folded rocks of post-Precambrian age.