This is an image of some Martian volcanoes.
Click on image for full size
Image from: NASA
The Martian Lithosphere
Like the Earth's lithosphere, the Martian lithosphere is the not-so-rigid part of the crust of Mars which is cooler than the interior of Mars somewhat like the film on top of a cup of hot cocoa. On Earth, the lithosphere can be pushed in response to the warmth of the Earth. Warm magma rises to the very surface and pushes the cooler, rocky lithosphere aside. The lithosphere then subducts, melts, and becomes part of the warm rising magma again. Thus on Earth, the recycling of the lithosphere keeps the lithosphere from becoming too thick.
Unlike the Earth, the rocky material which comprises the lithosphere of Mars does not contain enough trapped water to allow the rocky material to slide against each other. Since portions of the rocky material cannot slide against each other, the lithosphere cannot make way for hot, rising magma from the interior of Mars. Thus the lithosphere stays in place and thickens by cooling gradually. So it is that Mars does not have plates moving on the surface.
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