Okay, so you need at least two biomes: one mountainous, for the mountain features, and one non-mountainous, for the sand (unless you want to take your chances with the various glitches that can sometimes turn ground layers into sand, among other soil types). The non-mountainous region needs to have a magma pipe, too. Fortunately the OP didn't specify ttrees, so we can ignore that. The mountainous region needs to have a pit, HFS, and a river in each of the three tiles...
I've made maps with tiny tiny mountains. Mountain features get packed together in those situations, oftentimes to the point that not all of them can be placed. A site like this one is similar to what you're demanding, for example:
It's just 3x5 instead of 2x2, modded, and, IIRC, doesn't have sedementary rock. The big trick to these kinds of sites is to strongly limit your elevation ranges; maximum elevation should be 301 and minimum should be in the 285-295 range. Too low a minimum and "mountains" prevent civs from being able to access each other; too high and you don't get enough "mountains". "Mountains" is in quotation marks because they're barely higher than the local terrain and are themselves never tall at all.
You'll have a much easier time of it if you can accept a chasm instead of a bottomless pit. Pits take up only one mountain tile, while chasms are much bigger; thus, you have better odds of any given mountain tile having a chasm instead of a pit. Likewise, if you can accept not having access to sedementary rock (which, really, is not that big a deal, guys. Just use deathtraps to kill your first waves of invaders, and then melt their stuff down to equip your dwarves), then you won't have to bother with trying to get a volcano right next to a sedementary mountain.
Author
Topic: Want: 2x2 embark w/magma, hfs, bottomless pit, underground river + more. (Read 2368 times)