I’m thinking of the patterns here: File:Drought.jpg - Wikipedia
They’re the stereotypical “extreme drought” cracked earth patterns. How and why do they form?
Mud dries and shrinks. At some point in the shrinkage its cohesion to itself gives way and cracks form. They form a shape something like a honeycomb because things dry around the edges more while the center of a section stays relatively moister.
And that isn’t necessarily extreme drought. Some places get like that every year during the dry months.
It does depend on the material type, too. I suspect those materials have a relatively high percentage of silts and clays. Clay especially swells a lot when it’s wet. When it dries out - obviously, it shrinks a lot and leads to those characteristic patterns.
I remember studying this sort of thing in Design class, as an example of “potential energy.” Notice the proliferation of right angles, caused by equal energy on both sides of a new crack.
Evolution of mud-crack patterns during repeated drying cycles (or, as a pdf)
Same stuff happens with permafrost, and ice wedges: Origin of Ice Wedges