Scientific Investigations Report 2007-5039
U.S. GEOLOGICAL SURVEY
Scientific Investigations Report 2007-5039
Table 8. Elements of a resource classification (“McKelvey diagram”).
| Identified resources | Undiscovered resources | |||||
|---|---|---|---|---|---|---|
| Demonstrated | Inferred | Probability range | ||||
| Measured | Indicated | 90% | 50% | 10% | ||
| Economic | Reserves | Inferred reserves | Resources estimated in this report | |||
| Marginally economic | Marginal reserves | Inferred marginal reserve | ||||
| Sub-economic | Demonstrated subeconomic resources | Inferred subeconomic reserves | ||||