This image shows a series of curved ridges in the Hellas Planitia region of Mars. These ridges are highly contorted, or “bent,” in many different directions, and some ridges are broken into shorter segments.

These patterns resemble layers of rock that were originally parallel, but that have been compressed and deformed into folds. Plate tectonics is a common cause of compression on Earth, but plate tectonics is not expected to have been a significant process on Mars. Instead, these folds may have formed when rock layers at higher elevations started to slowly slide, or “creep,” downhill under their own weight.

There are a series of large mountains beyond the bottom of this image that rock layers could have slid down off of. The rock sliding down the hill would then compress and fold the layers at the bottom, as possibly shown in this image.

Written by: Chris Okubo  (24 April 2025)