Gully Activity in Triolet Crater

Gullies lying on the northeast slopes of Triolet Crater (about 11.6 km in diameter ), are located in the Southern Highlands just east of Gorgonum Chaos. Some gullies have eroded through resistant layers up to the crater rim.

At the downslope are fans of debris that overlap with those of nearby gully systems, suggesting that there were multiple periods of gully activity in this region. Just south of the gullies is a large fracture that cuts through the crater rim. This fracture is part of the Sirenum Fossae system that slices across the region for over 1,000 kilometers from the northeast to the southwest.

Because this fracture (or "fossae") cuts through the rim and ejecta blanket of Triolet Crater, this means that the crater is older than the fracture. This is known as a cross-cutting relationship and demonstrates a basic principle in geology known as the "law of superposition."

The map is projected here at a scale of 25 centimeters (9.8 inches) per pixel. (The original image scale is 26.5 centimeters [10.4 inches] per pixel [with 1 x 1 binning]; objects on the order of 80 centimeters [31.5 inches] across are resolved.) North is up.

This is a stereo pair with ESP_075675_1425.

The University of Arizona, in Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., in Boulder, Colorado. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington.