Prospecting in a mine?

[Leadpainter77]

If I have a minehole built where prospecting revealed tin, if I dig far enough can I uncover other metal?

and

If I prospect in a minehole, and it says something like "Iron below", does that mean nearby, since I'm already underground, or are there "layers"?

[sirbacon]

There are 5 Layers. Each requiring more strength to mine in. With each layer the quality of ore/stones go up and there are more nodes of rarer metals. Just to give you an idea of how much strength you need; our miner has to have a minimum of 320 strength to mine on layer 3 (most likely because we dug into a "hard node")

On a side note. When you find metal below, place your mine hole a few tiles away from where it said the metal is in order to minimize wasting ores from the tiles the mine hole occupies.

[the_portals]

Hypothetically you could uncover more metal, but you would have to dig for a while and get lucky.

Yes, there are layers to the underground world, 5 if I remember correctly. When you're underground and prospecting reveals ore, that means there is some ore below you. BUT! Don't build a mineshaft right on top of the ore, as you will destroy some of it. Dig 10-20 tiles away in any direction, then build the minehole there and dig in the direction opposite the one you just went.

[the_pilgrim]

If I have a minehole built where prospecting revealed tin, if I dig far enough can I uncover other metal?

and

If I prospect in a minehole, and it says something like "Iron below", does that mean nearby, since I'm already underground, or are there "layers"?

Review Sevenless' Guide. It has a mining section - viewtopic.php?f=2&t=19114
There's also a prospecting guide, though it hasn't been updated - viewtopic.php?f=2&t=18450&hilit=prospecting+guide#p213759