Western Mining History : Reliving the Industrial Revolution of the West

CLIFTON DISTRICT
The Clifton (Gold Hill) district is in the Clifton Hills near the Utah-Nevada boundary. Its ore de¬posits are varied and contain a wide range of valu¬able metal constituents. Besides gold, the deposits have yielded significant amounts of copper, lead, silver, and smaller amounts of tungsten, bismuth, molybdenum, and arsenic (Nolan, 1935a, p. 119).

The first mineral discoveries were made in 1858, but hostile Indians discouraged any mining in the area until 1869. In 1871 a smelter was built, and small amounts of silver, lead, and gold were produced for a few years. Interest was renewed in the area in 1892 when a mill was constructed to treat ores from the Cane Springs, Alvarado, and Gold Hill mines; total gold production from these mines from 1892 through 1895 was worth $207,896 (V. C. Heikes, in Butler and others, 1920, p. 475). Intermittent activity continued to 1917, when the completion of rail facilities enabled the deposits to be exploited on a larger scale. Much activity was maintained through 1934, after which production again dropped. The district was virtually idle from 1945 through 1959. Total recorded gold production from 1892 through 1959 was about 26,000 ounces.

The rocks of the Clifton district consist of a thick section of Paleozoic sedimentary rocks, chiefly dolomite and limestone, that range in age from Early Cambrian through Permian. These rocks are intruded by a stock of quartz monzonite and dikes of porphyry and aplite of Tertiary age. Five cycles of folding and faulting, beginning in Late Cretaceous or Eocene time and continuing to the time of the quartz monzonite intrusion, created a complex structural terrain that was further modified by normal faults of more recent age (Nolan, 1935a, p. 4-64).

The ore deposits of the district are of several diverse mineralogical and genetic types. Nolan (1935a, p. 97-103) classified them as:

1. Pipelike deposits locally containing tungsten and molybdenum.

2. Veins:

• Veins characterized by silicate minerals in the gangue.
• Veins containing chiefly quartz and metallic sulfides.
• Veins containing chiefly carbonate minerals with or without quartz.

• Arsenic minerals dominant.
• Copper-lead-silver minerals dominant.

The replacement bodies yielded most of the mineral wealth of the district; however, most of the gold came from veins in limestone beds near their contact with the quartz monzonite stock. These veins are characterized by abundant wollastonite and small amounts of zoisite, vesuvianite, garnet, and diopside. Chalcopyrite is the most abundant sulfide and is accompanied by pyrite, bornite, arsenopyrite, and galena. Quartz and calcite are locally abundant, and native gold is present in small quantities.