magnetic resonance logging - mean depth
- main gangway
- main gas generation phase
- main gas generation zone
- main gas window
- main gate
- main gravity incline
- main haul
- main haulage
- main haulage level
- main haulage line
- main haulage locomotive
- main haulage road
- main haulage roadway
- main haulage way
- main incline
- main indices and material requirements for ore processing
- main intake
- main joint
- main level
- main line haulage
- main loading and transportation drift
- main magnetic field
- main magnetic field reversal
- main material requirements
- main mine drainage
- main network
- main oil generation phase
- main oil generation zone
- main oil window
- main opening
- main pay
- main power users
- main processing building
- main receiver pressure
- main reef
- main reef leader
- main road
- main roof
- main rope
- main shaft