GOLD BRICK-QUARTZ CREEK DISTRICT
The Gold Brick-Quartz Creek district, which includes Box Canyon, is in southeast Gunnison County, 1 to 4 miles north and northeast of Pitkin. Much of the gold mined in this district was a byproduct of lead-silver ores. After the discovery in 1879 of a boulder of rich silver ore at the mouth of Gold Creek, prospectors flocked to the area and staked many claims in 1879 and 1880. The town of Ohio City was founded in 1881, and the following year the Denver, South Park, and Pacific Railroad reached the new town. Though few of the early claims were successful, lucrative deposits of lead and silver were found later, especially in the 1880's and early 1890's. By 1893 most of the shallow ore bodies were worked out and the price of silver fell at this time; consequently, there was little incentive to keep the mines open (Crawford and Worcester, 1916, p. 12-13). The district remained virtually deserted until 1934 when the increased price of gold stimulated activity, resulting in considerable gold production from 1934 through 1942. From 1943 through 1959 the district was again dormant.
Early records, though incomplete (Crawford and Worcester, 1916, p. 92-111), indicate that the district produced at least 80,000 ounces of gold through 1959.
The following summary of the geology and ore deposits of the district has been compiled from the reports by Crawford and Worcester (1916) and Dings and Robinson (1957).
The bedrock of the Gold Brick-Quartz Creek district consists of gneiss, schist, and granite of Pre-cambrian age, sedimentary rocks of Paleozoic age, and intrusive rocks of Tertiary age. The Paleozoic rocks range in age from Cambrian to Pennsylvanian. The Tertiary rocks are chiefly intrusive sheets and dikes and range from rhyolite to andesite and diorite porphyry (Crawford and Worcester, 1916, p. 22-68).
The ore deposits are chiefly fissure veins in the Precambrian rocks. Replacement deposits occur in some of the Paleozoic limestone and dolomite, but very little is known about them (Dings and Robinson, 1957, p. 63) and the amount of gold derived from them probably has been very small. The greatest values in the veins have been in silver, gold, and lead, and the lesser values, in copper and zinc. A few veins contain molybdenum and tungsten. Gold and silver vary in relative abundance. The bulk of the ore produced was limonitic quartz, and only a few mines produced sulfide ore; most mines have not reached a depth below the zone of at least partial oxidation, which extends to a depth of about 1,300 feet. Sulfide minerals found include galena, sphalerite, pyrite, chalcopyrite, arsenopyrite, tetrahedrite, argentite, and ruby silver in a gangue of quartz and local barite. Huebnerite and molybdenite are found in some veins (Crawford and Worcester, 1916, p. 82-83; Dings and Robinson, 1957, p. 62-63).
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