
Dark Mauritanian Mesas Create Asymmetric Sahara Dunes
NASA imagery shows three dark Paleozoic mesas in southern Mauritania slowing northeast winds on their eastern sides, causing sand to accumulate into dunes while the western downwind side stays largely dune-free due to wind scour; the pattern has persisted for at least a decade and is tied to varnish-coated caprock, offering a Mars-like analogue and prompting ongoing monitoring for dune dynamics and paleoclimate clues.












