- a coal bed
- a coal seam
Generated: This term refers to a layer or deposit of coal found underground, which can be mined for energy production. It is often part of larger geological formations.
The coal bed in this area is very thick.
Generated: This refers to a specific layer within a coal bed that has a certain thickness and is mined as a separate unit. It is often used in mining contexts.
The miners are developing a new coal seam.