Subject
Prospecting
Mines and mineral resources
9
Uranium ores
5
Geological surveys
4
Boring
3
Geology
3
Gold mines and mining
3
Chromite
2
Copper ores
2
Geiger-Müller counters
2
Geochemistry
2
Lead ores
2
Zinc ores
2
Black Ridge Canyon (Colo.)
1
Carnotite
1
Coal
1
Dominguez Canyon (Colo.)
1
Drill pipe
1
Geochemical prospecting
1
Geology Fieldwork
1
Geophysics
1
Gold ores
1
Hydraulic mining
1
Hydrothermal deposits
1
Mineralogy
1
Mining engineering
1
Ores
1
Palisade Wilderness (Colo.)
1
Petroleum
1
Placer mining
1
Sewemup Mesa Wilderness (Colo.)
1
Shaft sinking
1
Shaft sinking Costs
1
Uranium
1
Uranium Assaying
1
Volcanic ash, tuff, etc
1