Tharsis volcanoes

Tharsis volcanoes

. When Mars was young, it experienced internal adjustments that resulted in a swollen and cracked surface. The most prominent bulge, known as the Tharsis uplift, has four gigantic shield volcanoes on top of it. They are the Olympus, Arsia, Pavonis and Ascraeus Mons. Lava has flowed down the flanks of these volcanoes for perhaps a billion years, but the most recent eruptions could be 300 million years old, or less. Very old, presumably extinct volcanoes are also found on the Tharsis uplift, such as Ceraunius Tholus (Fig. 2.31) with an estimated age of 2.4 billion years.

Copyright 2010, Professor Kenneth R. Lang, Tufts University