Pit-chain in Noctis Labyrinthus

These pit chain features in south Noctis Labryinthus are oriented parallel to grabens in the area, suggesting that tensional stresses may have been responsible for their formation. One way in which pit chains can form is when something in the subsurface is removed or has a volume change, such as cooling lava in a subsurface lava tube. Extension of the crust by faulting is a second way in which this interesting features can form.