I created a wonderful, beautiful map in 34.07. If has clay, sand, freshwater, no stupid aquifers, natural defenses, no crazy evil mists, AND the very first stone level is mixed Dolomite/Bituminous Coal/Hematite/Magnetite. The only way this site could be more suited for dwarves would be if the little bastards didn't have to walk 150 squares to get all these buetific stones to the Magma Forge.
Fortunately 34.11 has minecarts to make this easy. Unfortunately my 34.07 fort-design is based on stairs, which do not work with minecarts safely. This is very important because I have immigration off, so I really really really can't afford to accidentally skoosh any of my loveable little twits. Even the 5-6 guys who mostly do hauling are incredibly important because that means the Legendary Weaponsmith isn't doing Hauling.
So I copied the world, abandoned in the copy, exported the worldgen info from Legends mode, and re-genned. But the new world has Microline clusters instead of Magnetite, and no veins of Coal or Hemetite.
Does anybody have any clue as to why this would change?
EDIT: Found the problem. When I added the worldgen parameters to the file I put them between the first [WORLD_GEN] tag and the Large Island parameters. I didn't add a new [WORLD_GEN] tag in front of the Large Island parameters, and apparently when DF has two mineral scarcities to choose from it picks the second one.