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  • Marisa Acosta

Wet Sand Structures (mini modern yardangs)

Updated: Nov 13, 2018



So I actually have no idea how these transient structures form, but they were everywhere on my last trip to the Florence, OR beaches. It seems to be an interplay between rain-wet sand and wind sculpting.

UPDATE: they are miniature modern yardangs, a feature created by wind erosion of less resistant material (Josh Roering, Pers. Comm.)


They look like little hoodoos. Probably the tops of them are more resistant to wind erosion because they were the last to be wet/were the most wet, lending them exaggerated cohesion. Maybe they were depressions in the sand where water puddled, and that explains their random spatial distribution and primarily vertical stance.


Some of them were tilted planar features, or maybe toppled versions of the vertical ones (?). I lean towards calling them the wet, dipping edges of piles of sand, but that doesn't quite look right for how closely they are spaced & the angle at which they are dipping...


An alternative explanation is that the wind scoured them that way, blowing obliquely with respect to the plane.


The formation of the tops of the miniature hoodoos.

Some magnetite (black) and olivine (green) density separation worked by water and wind.

Just an adorable picture of my dog, who enjoys running on the beach because it's good on her arthritic hips.

Token beach image.



Mini shadow dunes

University of Oregon

Department of Earth Sciences

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