The Valles Marineris of Mars are the greatest canyons in the Solar System. In spite of intense scrutiny since their discovery by the Mariner 9 spacecraft in 1972, much of the Valles remains unexplored at the highest spatial resolutions. We are often surprised when we get a fresh look inside these magnificent canyons.

Here in eastern Candor Chasma we get a glimpse of a layered sedimentary deposit on the canyon floor. Some regularly repeating process produced laminations several meters thick that were then bent and twisted by tectonic forces. The sediments were deposited sometime after the canyons were formed, but have since eroded away to leave small remnants such as this, with tantalizing clues to their depositional and deformational history.

Written by: Paul Geissler  (14 August 2025)