Bizarre TARs

These strange features in Syria Planum are still being widely debated. They have the same general form as transverse aeolian ridges (TARs) elsewhere on Mars; windblown deposits that are common in the Martian tropics. Their height and spacing are similar to the more familiar looking TARs in other places, and they are similarly bright. Unless Nature is perverse, they were both made by the same process.

Yet the TARs here in Syria Planum appear different than typical TARs elsewhere on the planet. They have blunt edges, in contrast to the tapering ends of typical TARs. The ridge crests are serrated, unlike the smooth crests of most TARs. They are layered on their upwind faces and scoured on the downwind sides, whereas TARs are usually smooth and symmetric. Why are these TARs bizarre?

A possible answer is that the features here in Syria Planum are at a different stage of evolution than TARs elsewhere, and are either younger or older than typical TARs. We can look at an enhanced color cutout to see whether this can be the case.

http://photojournal.jpl.nasa.gov/catalog/PIA19942