Cripple Creek, on the flanks of the Pikes Peak [massif], has produced more than $400,000,000 worth of gold. The Sangre de Cristo Mountains are visible in the distance beyond the Arkansas River valley. (Jack Rathbone photo)
In 1890, two sheepherders stumbled on some richly mineralized rocks near Cripple Creek. A boom developed immediately, for the rocks contained both gold and silver. Since then, the area has produced more than 2,000,000 ounces of silver and nearly 19,000,000 ounces of gold.
Cripple Creek has produced almost half of all the state’s gold and silver. The ores are located in or at the edge of a large mass of middle Tertiary volcanic rocks which form an elliptical basin or [caldera] several miles across. The caldera, surrounded by Precambrian [gneiss] and [granite] of the Pikes Peak [massif], was probably formed by collapse of a volcanic center that had erupted through the older rock. The collapse shattered the rocks around the basin margin, and subsequent volcanic activity introduced mineral-rich solutions into the many [faults] and fissures produced by the collapse. Tellurides of gold, silver, and copper, as well as [pyrite], [sphalerite], [galena], [tetrahedrite], and other minerals, are characteristic.
Climax
At Climax, the ore occurs scattered through the intrusive Climax [Granite] [Porphyry] and the intruded Idaho Springs Formation. Visitors can tour the surface workings during the summer months.
Tertiary [dikes] Shell of Climax [stock] Core of Climax stock Ore zone Precambrian [granite] [Fault] Dykes
Molybdenum now ranks as the number one metal mined in Colorado. Over $105,000,000 of “moly” was mined here during 1969, almost all of it from the Climax Mine, the world’s largest single source of this metal. The Climax deposit is located high on the west slope of Ten Mile Range in central Colorado, about 100 miles southwest of Denver. It is in the central part of the Colorado mineral belt, near the Mosquito [Fault], a prominent structural feature which extends about sixty miles along the north-south trend of the mountains. Rocks on both sides of this fault are intruded by Tertiary [granite] [dikes], sills, and stocks. The Climax Mine is in a [stock] just east of the fault, near the axis of a broad [anticline] in Precambrian metamorphic rocks.
Ore minerals at Climax are [molybdenite], [huebnerite], and [cassiterite]; [pyrite] is recovered also for the manufacture of sulfuric acid. The ore is very low in metal content, containing only one-third of a percent of molybdenum, 0.005% tungsten trioxide, and 0.0001% tin. The great size of the ore body and efficient recovery by modern methods make Climax a profitable mine, however. Production has risen each year since the mine began operation.