Dutch Flat District
Overview
Other Names: Florence, Willow Point
County: Humboldt
Discovered: 1893
Active: 1912
Commodities: gold, silver, mercury, tungsten, copper, lead
Comments
This district is located 20 miles north-northeast of Winnemucca in the southern portion of the Hot Springs Range. The original gold placer district was known as Dutch Flat or Florence. Lincoln (1923) described a Willow Point district, located about 20 miles north of Winnemucca, that possibly was this district, although the reported production of copper may not fit the geologic setting.
References
U.S. Geological Survey, 1910, p. 517; Lincoln, 1923, p. 105; Stoddard, 1932, p. 48; Vanderburg, 1936a, p. 94; Vanderburg, 1938a, p. 21; Bailey and Phoenix, 1944, p. 90; Willden, 1964, tables 14, 15; Bonham, 1976; Stager and Tingley, 1988, p. 74
Dutch Flast Placer District Description
Location
West flank of the Hot Springs Range, on the east side of Para- dise Valley, T. 38 N., R. 40 E.
Topographic Maps
Bliss and Osgood 15-minute quadrangles.
Geologic Maps
Hotz and Willden, 1964, Geologic map and sections of the Osgood Mountains quadrangle, Humboldt County, Nevada (pi. 1), scale 1:62,500.
Access
From Winnemucca, about 13 miles north on U.S. Highway 95 to junction with dirt road leading east across Paradise Valley to Sodarisi Canyon and Dutch Flat placers.
Extent
The placers of the Dutch Flat district occur in a small area about 1 mile from east to west and 2,000 feet from north to south, in the alluvium of Sodarisi Canyon and El Paso Gulch between Hot Springs Ridge and Belmont Hill, and at the head of the alluvial fan at the mouth of Sodarisi Canyon (sec. 17, T. 38 N., R. 40 E.).
The placer deposits contain gold, scheelite, and cinnabar in economic quantities and occur in stream deposits along the gulches and in the alluvial fan, and in slope wash as high as 50 feet above the sides of the gulches. The stream deposits are 10—35 feet thick along the gulches; the slope-wash deposits are 5—25 feet thick.
The alluvial-fan gravels are known to be at least 90 feet thick in some placers. The size, and possibly the concentration, of the various minerals change with distance from the source in the upstream end of the gulches. Assays based on the price of the metals in 1954 indicate an average value of $1.50 per yard of gravel in the lower stream gravels and alluvial fan. Values of placer gravels in the slope wash run higher, probably owing to the presence of large nuggets.
Production History
The Dutch Flat placers were discovered in 1893 and reportedly produced $75,000 in placer gold the first year after discovery. Estimates of total production of $100,000-$200,000 before the 1930's have been made, but recorded production figures do not support these estimates.
However, it is possible that actual production was higher than recorded production, for before the 1930's the placer area was for many years leased to several individuals engaged in small-scale operations who might not have reported the amount of gold recovered. Lack of water for placer mining apparently has inhibited attempts at large-scale mining.
Gold recovered from the Dutch Flat area was frequently credited to the "Paradise Valley district" by Mineral Resources and Minerals Year-books. The Paradise Valley district proper is on the east side of the north end of the valley in the Santa Rosa Range, and, although some placer gold is said to have been recovered from the area, the discussions under "Mine descriptions" for most years of production indicate that the gold originated in the Dutch Flat district.
Source
The gold, scheelite, and cinnabar in the placers were derived from two, possibly three, different sources. The gold was derived from erosion of gold- and base-metal-bearing quartz veins that cut a small granodiorite stock (sees. 16 and 17, T. 38 N., R. 40 E.) of probable Cretaceous age and the Harmony Formation of Cambrian age; these veins also contain a few small grains of scheelite.
The cinnabar occurs in fractures and interstices between mineral grains in Harmony sandstone, and is apparently slightly younger than the gold veins. Willden and Hotz (1955, p. 665) think that contact metamorphic deposits may be present in the district and may have contributed the scheelite (and accessory garnet) found in the placers.
Literature
Hotz and Willden, 1964: Summarizes earlier report (1955) on gold-scheelite-cinnabar placer; adds detailed information about lode deposits that were source of placers.
Vanderburg, 1936a: History of placer mining in area; estimates of early production; methods of placer mining; extent and depth of placer gravels; size of large nugget; average fineness of gold. 1938b: History; early production; average depth and value of gold-bearing gravel; placer operations in 1904; distribution, size, and fineness of placer gold.
Willden, 1964: Describes error in location of Paradise Valley district by earlier writers.
Willden and Hotz, 1955: Detailed description of three metals in placer deposits; extent of placer area, values of metals in placers; source of metals; variation in size of metals with distance from source.
Dyer District
Overview
Other Names: Independentia, Independence
County: Esmeralda
Discovered: 1863
Commodities: silver, lead, gold
Comments
District covers a small area on the western edge of the Silver Peak Mountains, east of Dyer Ranch. The Independentia district, organized in 1865 on the western slope of the mountains east of Fish Lake Valley, may have included the area of the present Dyer district. Spurr (1906) mentioned work in Dyer in 1863-64, and the Territorial Enterprise (1866) described the Independence district as being the western part of Red Mountain, extending across Fish Lake Valley to the White Mountains, and overlapping the Cottonwood (Red Mountain) district.
References
Territorial Enterprise, July 4, 1866, 1:3; White, 1871, p. 105; Spurr, 1906, p. 34, 84; Hill, 1912, p. 206; Lincoln, 1923, p. 66; Stoddard, 1932, p. 37; Gianella, 1945, p. 52; Albers and Stewart, 1972, p. 66
Dyke District
Overview
Other Names: Dyke Canyon, Florence, Boyd Basin
County: Humboldt
Commodities: silver, gold, antimony
Comments
Located in Dyke Canyon and Boyd Basin on the east slope of the Pine Forest Range. The district includes the Homer Verne Mine area.
References
U.S. Bureau of Mines, 1937, p. 450; Lawrence, 1963, p. 80; Bonham and others, 1985
