Mineral resource potential and geology of the San Juan National Forest, Colorado

Abstract

USGS BULLETIN 2127: MINERAL RESOURCE POTENTIAL AND GEOLOGY OF THE SAN JUAN NATIONAL FOREST• The San Juan National Forest ("the Forest") contains many famous mining districts, such as those at Rico and La Plata, but there is no significant mining being done within the Forest today.• Fourteen types oflocatable mineral deposits were assessed, and, of those, five were assessed quantitatively.• The five, quantitatively assessed, undiscovered locatable mineral deposits could possibly contain as much as 136,500 metric tons of copper, 17 metric tons of gold, 223,000 metric tons of zinc, 1,425 metric tons of silver, 184,000 metric tons of lead, and 33,900 metric tons of molybdenum. The probability that these amounts exist is 10 percent or less.• Estimates were made of the amount of leasable commodities, including conventional oil and gas, gas in tight (impermeable) sandstone reservoirs, coal, and coal-bed gas that could be present in the Forest.• Sixteen million barrels of oil and 26 billion cubic feet of gas or more may be present in conventional reservoirs.• Recoverable gas in tight gas reservoirs may total as much as 18 billion cubic feet.• Six billion short tons of bituminous coal may be present.• Coal beds may contain 1 1/2 trillion cubic feet of gas.• Considering the vast size of the Forest, the estimated amounts of leasable commodities are relatively small.• Most leasable minerals are concentrated in a small southern area of the Forest that overlaps the energy-rich San Juan Basin.• It is not implied that any commodities, leasable or locatable, could be extracted for a profit, even if they were discovered.• Salable minerals, such as sand, gravel, and building stone, are abundant within the Forest.