I would totally do the principle of superposition? Sounds complicated but it’s not. I’m sure you’ve driven by a cliff side and seen the kind with different lines in the rock from sedimentary deposits… Superposition just says that in undisturbed sedimentary layers the layer on top is younger than the one below it so on and so on.

I’d build two of them that way you could also show faults. A slip fault, normal and thrust. It’d be great, a model showing three geological principles

Superposition

Stratification

and faults.

As far as materials the only thing I can think of is get two stacks of paper and mark the sides in different color denoting layers.

you ought to attempt . . “Whose mouth is cleanser, a dogs’s mouth or a human’s mouth?” (remember the regulations of the honest and if mildew is permitted etc) start up off with 4 petri dishes packed with gelatin. Then take a swab of your mouth, yet another persons mouth, a dogs’s mouth and yet another dogs’s mouth. placed those all in separate petri dishes. Then stated the upward thrust of distinctive molds and fungus on the swabs over a three weeks era. Sounds gross in spite of the incontrovertible fact that this is thrilling and childrens are fascinated . . . It has a “delusion-busters” vibe to it and that i could say this is a sort of “dental test.”