The mountainhomes have ordered a magma pump stack constructed! They have sent seven dwarves to found the outpost Munèstsazir -- Grovebridges -- an annoyingly elfin name that can only have been chosen to mislead the tree-huggers. Nobody knows yet what just what the regent is planning, but there will surely be suitably dwarfy!
The initial outpost has been constructed: small farms, carpentry, masonry, and a small dining room with nearby bedrooms. A smelting operation has been dug out to produce the bismuth bronze bars the mountainhomes have sent with the initial caravan to outfit the military guard that will arrive in later migrant waves. Why they insisted as such is unclear -- there are whispers that the metalsmith Kulet "Combinedoil" Artobuzol pulled some strings to indulge his tastes.
The initial mining stairwell to uncover the layout of the underground found only the first cavern (I think I need to stop digging my exploratory mines exactly in the center of a 4x4 map -- I might have better luck trying to dig in the middle of one of the tiles).
The next stairwell has better luck, breaching both caverns, and discovering a magma pool in the third cavern filled nearly to the level of the second cavern (which wasn't very far).
Unfortunately, in their infinite wisdom, the mountainhomes did not pick a site with sand. Despite flux, shallow metals, and deep metals, it appears to fail to have iron as well. I haven't dug out much yet, but my first stone layer is Gneiss; I'm very much a newbie at DF geology, but the wiki says that's metamorphic, and I think that means there's no chance of iron.
But there is
garnierite! I always feel a little silly to be happy to have nickel, but there you have it. I've seen lots of galena and cassiterite deep down too, and a bit of gold. Maybe I should do that minting commemorative coins thing, minting a stack of several types of metal each year.