So I’ve been doing some playtesting in RedPower World.
I spawned under an overhang, and it appears that the marble cave populator saw it as a valid target. The overhang was almost solid marble!
So the first thing I did was make a little hut out of marble bricks:
Marble is slightly softer than smooth stone, so this was actually a pretty sensible thing to do, considering the abundance of marble in this world.
And then I noticed that I spawned quite near to a volcano:
I nipped over there and got myself some basalt cobblestone. I also explored a nearby cave, and found a bunch of ore. Iron, copper, and tin! Shame I can’t do anything with the copper or tin yet. Oh well, that just gives me a reason to continue working.