Home > Term: natural air crossing
natural air crossing
An air crossing in which two airways are separated by rock in its natural state.
- Szófaj: noun
- Ipar/Tárgykör: Mining
- Kategória: General mining; Mineral mining
- Government Agency: USBM
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- ed.young
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(V.I.P) 21084 points - 100% positive feedback
(Milwaukee, United States)
