offset vertical seismic profiling - ore-hosting calcareous siltstones
- olivine-norite
- olivinic
- olivinite
- olivinoid
- ollenite
- olletas
- Olongrin strata
- olsacherite
- olshanskyite
- Olympic green
- olynthus
- ombrogenous
- ombrogenous peat
- ombrometer
- ombrophilous
- ombrophobous
- ombrotiphic
- omega-structure
- omission
- omission of beds
- ommatidium
- omnidirectional receiver
- omnidirectional source
- omnimeter
- omnipresent
- omphacite
- omphacitic amphibolite
- omphalopter
- omuramba
- on ... m intervals
- on a 25mx50m grid
- on a basis of calculated annual tonnage of removed and processed ore
- on plane
- on shift
- on site processing
- on the bed
- on the edge
- on the face
- on the rise
- on the strike