By A. H. KOSCHMANN and M. H. BERGENDAHL - USGS 1968
Prospectors attracted by the silver strikes at Reese River used the town of Austin as a supply point and headquarters from which they explored most of eastern Nevada. Rich silver ore soon was discovered at Battle Mountain, Egan Canyon, White Pine, and Pioche. Indeed, it was probably the rich silver strike at White Pine that influenced the formation of White Pine County from part of Lander County in 1869.
The mines of the county have been noted chiefly for their high-grade silver, copper, and lead ores, but considerable quantities of gold have been produced from the Cherry Creek, Ely, and Osceola districts. Gold production of the county from 1903 through 1959 was 2,049,895 ounces.
CHERRY CREEK DISTRICT
The Cherry Creek (Egan Canyon, Gold Canyon) district is in the Egan Range, 50 miles north of Ely.
Gold was discovered here in 1861 by a group of soldiers, and the district was organized in 1863 (Lincoln, 1923, p. 243). Ores rich in silver, gold, and lead were mined on a fairly large scale from 1872 to 1883. The principal mines during this early period were the Teacup, Star, Exchequer, and Cherry Creek. In the late 1880's a decline began, culminating in a virtual shutdown in 1893. By 1895, however, the district had revived and the mines continued to produce on a small scale (Schrader, 1931, p. 29).
Estimates of the early production range from $6 to $20 million in combined metals, but the amount of gold has not been determined. From 1902 through 1959 the district produced 36,197 ounces of gold. From 1952 through 1959 it produced considerable tungsten from scheelite deposits.
The rocks exposed in the Cherry Creek district are chiefly quartzite, shale, and limestone of Cambrian age intruded by small masses of quartz monzonite and diabase (Hill, 1916, p. 160-163). The ore deposits are veins in the quartzite. Ore minerals are galena, sphalerite, pyrite, stromeyerite, copper carbonates, scheelite, and gold (R. M. Smith, written commun., 1962).
The Ely (Robinson) district is slightly south of the center of White Pine County, 50 miles west of the Utah-Nevada boundary.
As a result of silver-lead-gold ore discoveries in the area, the district was organized in 1868 and was named the Robinson district after a member of the original party that entered the area. The first settlement in the district was Mineral City which by 1873 had a population of 600 (Spencer, 1917, p. 93).
The early years were characterized by desultory activity, and interest shifted to the Ward, Osceola, and Taylor districts. In 1886 the county seat was moved from Hamilton to Ely, an event that seemed to coincide with revived activity in the district. At this time silver and gold were the chief metals mined.
During 1906-7 there was much activity: ore bodies were developed, mills were constructed, and new companies were formed. Copper was first produced from porphyry ores in 1908, an event that marked the beginning of sustained significant production from the district.
Before 1902 accurate records of production were not kept. Spencer (1917, p. 98) estimated the production before that date at $500,000 to $600,000 in combined metals. From 1902 through 1959, a total of 1,959,659 ounces of gold was extracted from the copper ores of the district.
Spencer's (1917, p. 23-130) classic report on the Ely district is the principal reference for the following outline of the geology and ore deposits. Most of the area is underlain by limestone, quartzite, and shale aggregating 9,000 feet in thickness and ranging in age from Ordovician to Pennsylvanian. These have been extensively faulted and somewhat folded and then invaded by bodies of monzonite porphyry of probable immediate post-Jurassic age.
A long period of erosion followed; then in late Tertiary time the area was covered with tuff, agglomerate, and rhyolite flows. Recent erosion has stripped away most of this volcanic cover. Both the invaded sediments and monzonite porphyry were extensively altered, causing development of garnet, jasperoid, and marble in the limestone, pyritization of the shale, and development of sericite and deposition of chalcocite in the porphyry.
Ore deposits occur in an east-trending zone, 9 miles long and V2 to IV2 miles wide. The most important ore bodies are blanketlike masses of supergene-enriched pyritized monzonite porphyry, the chief ore mineral being chalcocite. Small amounts of gold, silver, and other metals are recovered. Small bodies of copper ore are also found in the sedimentary rocks near the monzonite contact, and bodies of silver-lead ore occur farther from the monzonite.
The Osceola district is on the west slope of the Snake Range, 35 miles east of Ely. Work began in 1877 on the gold placers of Dry Gulch and continued to 1900 (Weeks, 1908, p. 122-123) ; there was also small-scale production from lodes during the early days. To 1907, the placers had produced gold worth about $1,800,000, and the lodes, about $200,000 (Weeks, 1908, p. 123).
After 1900, the district has had a lethargic development with only brief productive intervals. Total gold production through 1959 was 131,700 ounces - 91,555 ounces was from placers, and 40,145 ounces was from lodes.
The following is summarized from Weeks (1908, p. 119-127). The oldest rocks, exposed near the crest of the Snake Range a short distance south of the district, are granite and schist of Precambrian age. These are overlain by a thick section of Cambrian formations consisting of conglomerate, argillite, quartzite, shale, and dark-blue and gray limestone.
Locally, granite porphyry of post-Carboniferous age has invaded the sedimentary rocks. Ore deposits are of two types: (1) sheeted zones, and (2) shattered masses in quartzite adjacent to deposits of the first type. All deposits dip steeply and are confined to well-defined zones in the quartzite. Gold is the only economic constituent; quartz is abundant and pyrite is sparsely disseminated in the veins.
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