1) underground mining
2) deep mining
3) underground working
the mining in which access to the mineral deposits is obtained by means of shafts and underground workings
GRM: n. (1,2,3)
References:
GEN working
GEN winning
GEN mining
GEN extraction
GEN breaking
SEE surface working
SEE surface mining
SEE open cast mining
SEE openpit mining
SEE placer mining
SEE opencut mining
SEE opencast mining
SEE opencast
SEE open-pit mining
SEE open-cut mining
SEE open mining

ENERGY TERM COURTESY OF ENERGY.EU