Ceraunius Tholus and Uranius Tholus Target Name:   Mars Spacecraft:   Viking orbiter Produced by:   Calvin J. Hamilton Copyright:  © Calvin J. Hamilton (Publisher Permission Request)

• Martian Volcanoes

Ceraunius Tholus (bottom) shows several incised valleys cut into its flanks which indicate that it was easily eroded and probably consists of ash deposits due to explosive activity. The lower flanks of the volcano have been buried beneath the plains material. Ceraunius Tholus is about the size of the Big Island of Hawaii. Uranius Tholus (Top) also shows similar characteristics to Ceraunius Tholus. A major impact crater, just above Ceranius Tholus, postdates the plains material and volcano. However, a prominent delta of probable volcanic material was emplaced within the impact crater at the mouth of a sinuous channel that extends up the flank of Cerauius Tholous to the summit crater.

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