linear features on Mars

[markse68]

I’ve read the early observations of “canals” on mars dismissed as optical illusion but looking at a couple of really excellently detailed recent images by @astroman001 and @AbsolutelyN I couldn’t help but notice distinctly linear patterns over wast areas of the darker areas. They seem to really stand out in the IR. Is there a known cause for this? Is it wind rippled dunes (on a massive scale!) of the regolith over the darker bedrock? Or something explained by historic geological process? Or is it some kind of processing artefact? 

Mark

[AbsolutelyN]

I suspect with my image it's possibly over sharpening artefact. Still figuring out how best to process so experimenting lots.