Alternating dark and light terraces inside Valles Marineris

Cool image time! The picture to the right, cropped and enhanced to post here, was taken on October 9, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and shows what appear to be the somewhat typical terrain at this location, in a part of the giant Martian canyon Valles Marineris dubbed West Candor Chasma. For example, I featured similar swirls in August 2022 at a place only about six miles to the east, that spot indicated by the green dot on the overview map above. The white dot marks the location of today’s image.
So, what are we looking at? The elevation drop from the high and low points is only about 180 feet, but in that short distance it appears there are more than two dozen visible layers, and those layers form terraces that alternate between bright and dark material.
The shape of the swirls also suggest that a flow of some kind, either water, ice, or wind, moved from the northwest to the southeast, carving these terraces as it descended the stair steps downward. It is also just as likely that we are seeing repeated lava flows going downhill to the southeast, each even laying another layer on top of the preceeding one. And it is also possible that we are looking at a combination of both.
The alternating dark and light layers suggest that each dark layer was an event that put down dark material, such as volcanic dust, that was subsequently covered with light material, with this process repeating itself many times over the eons.
That the floor of this part of Valles Marineris is uniquely covered in this manner is in itself intriguing. Why here, and not elsewhere within the canyon?
Cool image time! The picture to the right, cropped and enhanced to post here, was taken on October 9, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and shows what appear to be the somewhat typical terrain at this location, in a part of the giant Martian canyon Valles Marineris dubbed West Candor Chasma. For example, I featured similar swirls in August 2022 at a place only about six miles to the east, that spot indicated by the green dot on the overview map above. The white dot marks the location of today’s image.
So, what are we looking at? The elevation drop from the high and low points is only about 180 feet, but in that short distance it appears there are more than two dozen visible layers, and those layers form terraces that alternate between bright and dark material.
The shape of the swirls also suggest that a flow of some kind, either water, ice, or wind, moved from the northwest to the southeast, carving these terraces as it descended the stair steps downward. It is also just as likely that we are seeing repeated lava flows going downhill to the southeast, each even laying another layer on top of the preceeding one. And it is also possible that we are looking at a combination of both.
The alternating dark and light layers suggest that each dark layer was an event that put down dark material, such as volcanic dust, that was subsequently covered with light material, with this process repeating itself many times over the eons.
That the floor of this part of Valles Marineris is uniquely covered in this manner is in itself intriguing. Why here, and not elsewhere within the canyon?