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It is called "erosion" and you're part of the link ;-)
Ignoring the litho-, hydro-, atmo- and biosphere that built the stuff in the first place and delivered the processes for such formations to occur, including the algae mats.
Seriously, would be cool to know if that's a real photography or something rendered (real time I mean, not overnight). My bet is photography because of the water. These types of things aren't suitable for real time rendering, if you haven't millions to invest and a bunch of programmers to assign, like the Unreal Engine. And even then it is huge project. Sometimes expectations and reality just won't fit together.