From above the surface of Mars, the High Resolution Imaging Experiment (HiRISE) orbits in Danielson Crater, north of the Martian equator. This area is of great interest to space geologists because of the stratigraphic sediments that line the crater.
Layered sediments can be found all over Mars, but Danielson Crater contains some of the most amazing and best preserved. Even more impressively, they appear to be evenly spaced, with varying levels of wear: stronger layers form steps, with layers of weaker material inside.
The equality of these layers means that they cannot be created by random processes, such as impact events. Instead, scientists believe that a regular, repetitive process led to the sedimentation of the strata.
A 2019 NASA blog explained: “Rocks were formed millions or billions of years ago when bulk sediments settled into the crater, one layer at a time, and subsequently solidified in place. Periodic variations in the sediment properties have made some layers more resistant to erosion than others. Eons later. “These tougher layers protrude outward like steps of a ladder. Through these steps, the wind disperses the sand, creating zebra-like patterns.”
On a small scale, there are large areas of highly fractured rock. Scientists studied these fractures and determined that because the pieces fit perfectly together, this happened after the sediments had already turned into rock.
Some scientists have suggested that the cyclical process may be the result of climate change associated with the orbital changes of Mars. Another study suggests that rising groundwater levels may be responsible.
And there are plenty of wonderful Martian rocks that planetary geologists would love to take a personal look at. Meanwhile, orbiters equipped with amazing cameras, such as HiRISE, are helping to reveal the fascinating history of Mars.