Four huge shield volcanoes have been seen on Mars, plus many smaller ones like those on the Earth. Most of Mars' major volcanic structures are in two regions where the crust has swelled upward. These crustal uplifts also are found on Earth, but not on the Moon. Near the four giant shield volcanoes is an immense crack in the crust of Mars. Such a mammoth gorge in the United States would stretch from San Diego to Boston.
Rift valleys are well known on Earth, of course.
For instance, in Africa they represent the breakup of that continent into two separate plates. Rifting is the first step in plate tectonics, the beginning of plate formation. The process seems to have started on Mars, but the planet cooled too much to have the active plate movements we know as earthquakes and volcanic eruptions. Despite its Earth-like geologic structures, most of Mars looks like the Moon. Elevated cratered plains dot the southern hemisphere, like the highlands of the Moon.