WASHINGTON COUNTY HISTORICAL SOCIETY (Washington County, Utah)
GOLDSTRIKE MINING DISTRICT
in Washington County, Utah
LOCATIONThe Goldstrike mining district is located in western Washington County, about 35 miles northwest of St. George. See the map.
HISTORYGold was discovered in the district sometime in the late 1800s and the area was being actively prospected by 1895. This early work did not lead to any significant production although a total of 40 lode claims and 1 placer claim were brought to patent as a result of the early work. The area was largely ignored until the mid-1970s when a search was begun for disseminated gold deposits of the type then being actively mined in central Nevada. This search was successful and led to the production of approximately 200,000 ounces of gold and a somewhat smaller amount of silver from 12 near-surface deposits. The bulk of the ore in eight of these deposits was found in a sandstone host rock occurring at the base of the early Tertiary Claron Formation. High-angle faults appear to have been important in localizing ore in these deposits as well as in the other four deposits, where most of the ore occurred in brecciated and silicified Paleozoic limestone units.
The pre-Tertiary rocks in the district are complexly folded and faulted and record a long history of tectonic activity that culminated in extensive overthrusting of the Paleozoic rocks onto a sequence of clastic rocks of Mesozoic age. This overriding thrust is not exposed in the Goldstrike district but most likely underlies the entire district. Following this period of thrusting the area was nearly beveled by erosion. The Claron Formation was then deposited across the beveled surface, followed by extrusion of large volumes of volcanic tuffs. Later high-angle faulting offset the Tertiary rocks and formed conduits for the mineralizing solutions that produced the gold-silver ore bodies.
MILLS & SMELTERSTBD
REFERENCESGoldstrike mining district, Washington County, Utah
by Ronald Willden
Pages 458-476 in Mining Districts of Utah, Utah Geological Association Publication 32
R. L. Bon, R.W. Gloyn, and G. M. Park, editors, 2006
(663 pages, published as pdf-format file on CD)