Ascraeus Mons Summit Target Name:   Mars Spacecraft:   Viking orbiter Produced by:   Calvin J. Hamilton Copyright:  © Calvin J. Hamilton (Publisher Permission Request)

• Martian Volcanoes

This complex caldera is composed of several discrete centers of collapse where the older collapse features are cross-cut by more recent collapse events. The lowermost circular floor preserves the last lava flooding event that followed the last major collapse. The southern wall of the caldera has at least 3 kilometers (1.9 miles) of vertical relief with an average slope of at least 26° (from horizontal). The caldera complex truncates several lava flows, indicating that the flows predate the collapse event and that their source areas have been destroyed by the caldera formation.

This image is Copyright © by Calvin J. Hamilton. Any commercial/for-profit use of this image needs to be addressed to Calvin J. Hamilton. The caption is from LPI.