Tag Archives: crossbedding

Uniquely martian

A piece of Mars: Now here's something that, as far as I know, can safely be labeled as "uniquely martian". These dunes (or maybe they're ripples) are ~25 m wide, and have formed from winds blowing from the upper left. ...

Ribbons on Mars

A piece of Mars: Bet you didn't know there were ribbons on Mars. Long, sweeping, velvety lines, delicately frayed at the ends. These are actually ancient ripples, formed by a wind blowing from right to left. Stripes on the ripples ...

Little dunes that Curiosity saw last October

A piece of Mars: On Oct. 15, 2013, Curiosity drove past a crater that has small dunes or ripples on its floor. In a new HiRISE image, you can see Curiosity's tracks from that day (its 424th sol on Mars). ...

Two-toned washboard on a hillside

A Piece of Mars: Two-toned ripples have formed on a steep slope, created by winds rushing downhill (from top to bottom in this frame). The larger ones are big ripples, with peaks more than 30 meters apart. What makes them ...

Spines

A piece of Mars: Here are some old dunes that look a little like vertebrae of fossils (if you think they look like dragon spines poking out of the ground then you're playing too many video games). The white areas ...

Mysterious textures

A piece of Mars: Dunes don't usually have a rough surface texture like these do. It's not clear what's going on. Are they ancient dunes that are being eroded? What causes this particular texture? It seems unique to high elevations ...

Dune cannibals

A piece of Mars: Dunes often cannibalize each other, with new dunes forming from the sand in older dunes. Here the tan dunes have formed from the sand that made up the grayish blue dunes. Notice the banding on the ...

A beautiful tangle

A piece of Mars: Compare this with my post five days ago and you might think the scenes are similar. In fact they're not. In the previous case sedimentary layers were carved out by the wind, leaving behind swirly patterns ...