The Make up of Mars 3

Crack On!

Create a Canyon

This is an exercise in simple plate tectonics. You can see how rift valleys and canyons are made.

The central region of the Valles Marineris © NASA


All you need is some sheets of paper, a large tray and some sand.


Put two pieces of paper on the tray with one edge of each touching or slightly overlapping. heap the sand onto the paper and pat it into a solid dome

Now move the sheets of paper apart away from each other, and see what happens.

Re-form the sand and do the same again, but this time move the pieces of paper parallel to each other. Do you notice a difference in the cracking patterns of the sand? This action is called shear and it is what happens when plates move past each other rather than away from each other. This is what is happening in California, along the San Andreas fault, which is where the edges of the Pacific plate and American plate meet.

Recent finding by Mars Global Surveyor suggest that plate tectonic processes occurred on Mars. Some of the great canyons may have formed through tectonic action, or crust movement.

Further Tests

See what difference the dampness of the sand makes. Damp sand will tend to retain its shape, like large pieces of rock.

Return to rover


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