How far down is a good seam of coal?

Question

I was just wondering....how far under the ground is a "good" seam of coal and how thick does this seam need to be for a company to consider mining it? Would it be worthwhile for a company to have to drill down 60-80 feet for a 3-foot seam of coal?

Answer 1

The depth to the coal varies. In some areas it would pay to strip mine. They just rip off the plants, the earth, any rocks, and anything else in the way till the seam is uncovered. Then they can cut the coal right off the new surface.

A seam could be close to the surface at one point and far down at another. Some of them are very deep and miners need to go down in elevators to get to the face of that seam - so strip mining is not an option always.