ore-leaching tank - pad construction
- outsized waves
- outskirts
- outstanding sample
- outthrust
- outward forcing
- outward from
- outward mining
- outward working
- outwash
- outwash area
- outwash fan
- outwash gravel
- outwash plain
- outwelling
- ouvarovite
- ouyheeite
- oval-strand rope
- ovarian
- oven
- ovenstone
- over
- over 1m to 2m strike width
- over a strike length of km
- over cut
- over head wire locomotive
- over riding
- over the ellipse
- over the whole deposit
- over-corrected event
- over-migrated data
- over-placement
- overall balance
- overall cross-section
- overall depth
- overall program
- overall rock section
- overall scaling
- overall shape of the deposit
- overall slope angle
- overarch