Highlights

• Ancient aeolian and fluvial bedforms were mapped and characterized across Mars.

• A range of Martian paleo-bedform classes and preservation states were observed.

• Wholly preserved bedform fields are more common on Mars than Earth and provide clues to the history of paleoclimate and diagenesis.

Sedimentary processes on Mars have contributed to a plethora of landforms, both ancient and modern.

Paleo-bedforms on Mars are notably more widespread and common relative to Earth, suggesting more suitable conditions for their preservation and exposure on Mars. The preferential destruction or burial of bedforms by the relatively high-energy landscape evolution and crustal recycling operating on Earth can only account for some of this disparity.

In comparison, Martian planetary conditions appear well-suited not only for dune and ripple formation but also for their preservation in the geologic record. Some bedform fields may have been buried during their formation by various units (e.g., pyroclastic units, lava flows, fluvial-lacustrine units, ice, dust) until processes such as mass wasting, aeolian abrasion, and cryo-driven erosion contributed to their exhumation.

Erosion continued for some dunes, which were then cast into shallow depressions of their shape. In contrast, other sites lack evidence of burial-exhumation, instead showing indications that bedforms can evolve from mobile sand into rock while exposed on the surface. The wide variety of ancient sedimentary bedforms preserved across Mars speaks to the diversity of dynamics and conditions operating in the solar system.