One method I like using for dead ends is collapsed hallways (like in the maps of the Temple of Illhan the Binder). For some reason, I didn’t make any ruined areas in the geomorphs so far (well, maybe a couple have torn down walls here and there).
So today’s dead end geomorph is the result of a section of the geomorph collapsing.

Geomorph 16f
I love the dead-end set.
Inspired! One of my favorites.
Nice!
Now, that is a Geomorph I can dig into!
Best,
TB
Maybe you’ve got your theme for another week… collapsed hallways.