This image spans the floor of Ius Chasma's southern trench. Ius Chasma is
located in the western region of Valles Marineris, the solar system's
largest canyon. This canyon is well known for its fine stratigraphic
layers modified by wind and water.
The outcrops contain interchanging layers of dark and bright rocks. The
layered deposits consist of dark basalt lava flows and bright sedimentary
layers. The sediments are likely to be from atmospheric dust, sand, or
alluvium from an ancient water source. The layers are visible on the
gentle slopes above the canyon floor, in pitted areas, and in small mesa
buttes. The floor of the canyon is littered with megaripples that are
aligned in a north-south direction.
Ius Chasma is believed to have been shaped by a process called sapping
when water seeped from the layers of the cliffs and evaporated before it
reached the canyon floor. This process is thought to have dominated during
the Amazonian period.
Ius Chasma also has several structural features such as east trending
normal faults and grabens that deformed the canyons. Recent
geomorphological events include mass wasting (avalanches) and minor
sapping from gullies that continued to erode the canyon walls.
See the full University of Arizona press release.
NASA's Jet Propulsion Laboratory, a division of the California Institute
of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for
NASA's Science Mission Directorate, Washington. Lockheed Martin Space
Systems, Denver, is the prime contractor for the project and built the
spacecraft. The High Resolution Imaging Science Experiment is operated by
the University of Arizona, Tucson, and the instrument was built by Ball
Aerospace and Technology Corp., Boulder, Colo.
