Cross-bedding seen in the layers of this Martian rock is evidence of movement of water recorded by the waves or ripples of loose sediment the water passed over, such as a current in a lake. This image is from NASA's Curiosity Mars rover.
This view from the NASA's Curiosity Mars rover shows an example of cross-bedding that results from water passing over a loose bed of sediment. It was taken at a target called 'Whale Rock' within the 'Pahrump Hills' outcrop at the base of Mount Sharp.
This image from NASA's Curiosity Mars rover shows an example of a thin-laminated, evenly stratified rock type that occurs in the 'Pahrump Hills' outcrop at the base of Mount Sharp on Mars. This type of rock can form under a lake.
This evenly layered rock photographed by the Mast Camera (Mastcam) on NASA's Curiosity Mars Rover on Aug. 7, 2014, shows a pattern typical of a lake-floor sedimentary deposit not far from where flowing water entered a lake.
Bedding Pattern Interpreted as Martian Delta Deposition
On March 25, 2014, view from the Mastcam on NASA's Curiosity Mars rover looks southward at the Kimberley waypoint. Multiple sandstone beds show systematic inclination to the south suggesting progressive build-out of delta sediments.
This image from Curiosity's Mastcam shows inclined beds of sandstone interpreted as the deposits of small deltas fed by rivers flowing down from the Gale Crater rim and building out into a lake where Mount Sharp is now.
Within Rover's Reach at Mars Target Area 'Alexander Hills'
This view from ASA's Curiosity Mars rover shows a swath of bedrock called 'Alexander Hills,' which the rover approached for close-up inspection of selected targets. It is a mosaic of six frames taken on Nov. 23, 2014.
Fine-Grained, Finely Layered Rock at Base of Martian Mount Sharp
This patch of Martian bedrock, about 2 feet (70 centimeters) across, is finely layered rock with some pea-size inclusions. It lies near the lowest point of the 'Pahrump Hills' outcrop, which forms part of the basal layer of Mount Sharp.
Erosion Resistance at 'Pink Cliffs' at Base of Martian Mount Sharp
This small ridge, about 3 feet long, appears to resist wind erosion more than the flatter plates around it. Such differences are among the traits NASA's Curiosity Mars rover is examining at selected rock targets at the base of Mount Sharp.
This image from NASA's Curiosity rover shows a sample of powdered rock extracted by the rover's drill from the 'Confidence Hills' target -- the first rock drilled after Curiosity reached the base of Mount Sharp in September 2014.
'Confidence Hills' -- The First Mount Sharp Drilling Site
This image shows the first holes drilled by NASA's Mars rover Curiosity at Mount Sharp. The loose material near the drill holes is drill tailings and an accumulation of dust that slid down the rock during drilling.
Curiosity Mars Rover's Approach to 'Pahrump Hills'
This southeastward-looking vista from the Mast Camera (Mastcam) on NASA's Curiosity Mars rover shows the 'Pahrump Hills' outcrop and surrounding terrain seen from a position about 70 feet (20 meters) northwest of the outcrop.
The 'Bonanza King' rock on Mars, pictured here, was tapped by the drill belonging to NASA's Mars rover Curiosity. The tapping resulted in sand piling up on the rock after drilling, showing the rock was not firmly in place.
Curiosity's Brushwork on Martian 'Bonanza King' Target
NASA's Curiosity Mars rover used the Dust Removal Tool on its robotic arm to brush aside reddish, more-oxidized dust, revealing a gray patch of less-oxidized rock material at a target called 'Bonanza King,' visible from the rover's Mastcam.
This Aug. 12, 2012, image from the Mastcam on NASA's Curiosity Mars rover shows an outcrop that includes the 'Bonanza King' rock under consideration as a drilling target. Raised ridges on the flat rocks are visible at right.
This rock encountered by NASA's Curiosity Mars rover is an iron meteorite called 'Lebanon,' similar in shape and luster to iron meteorites found on Mars by the previous generation of rovers, Spirit and Opportunity.