FTP, name this kind of depression resulting from the collapse of a volcano.
These structural features are sometimes classified into two groups dependent on the presence of a strong positive or negative gravity anomaly. The second of these includes those that form from slow, stepwise subsidence, or the Masayan type, and those in which a vacuum is created by migration to adjacent chambers, the Atitlan type. All of the largest ones fall under the Valles classification, in which intrusion along arcuate faults creates a characteristic circular structure sometimes exposed by their erosion. That pattern, known as a ring dike, is typically offset by a concentric normal fault system, as rock slides inward to accommodate a sudden loss of supporting material. FTP, name this kind of depression resulting from the collapse of a volcano.
These structural features are sometimes classified into two groups dependent on the presence of a strong positive or negative gravity anomaly.
caldera