Round Mountain Mine (Round Mountain Gold Mine; Sunnyside Mine; Sphinx glory hole; Great Western tunnel; Rattlesnake; Keane vein; Los Gazabo vein), Round Mountain, Round Mountain, Round Mountain District, Toquima Range, Nye Co., Nevada, USA
|Latitude & Longitude (WGS84):||38° 42' North , 117° 4' West|
|Latitude & Longitude (decimal):||38.70000,-117.06667|
|Köppen climate type:||BSk : Cold semi-arid (steppe) climate|
An open pit Au-Ag-As-Sb-Th-Hg-Mo-F-Mn-W mine located in secs. 19 & 30, T10N, R44E, MDM, 0.9 km (2,800 feet) SE of Round Mountain (summit) (coordinates of record), and 1.2 km (4,100 feet) S of Round Mountain (town). Owned by Homestake Mining Co. (25%) & Round Mountain Gold Corp.
Workings include an open pit with a heap-leach operation.
Produced 4 million tons ore (= 3,720 kg Au) (1984).
14 valid minerals.
Rock Types Recorded
Select Rock List TypeAlphabetical List Tree Diagram
Entries shown in red are rocks recorded for this region.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
|Early Miocene - Oligocene|
15.97 - 33.9 Ma
|Intermediate silicic ash flow tuff|
Age: Cenozoic (15.97 - 33.9 Ma)
Stratigraphic Name: Bates Mountain Tuff; Caetano Tuff; Edwards Creek Tuff; New Pass Tuff; Fish Creek Mountains Tuff; Fraction Tuff; Pancake Summit Tuff; Northumberland Tuff; Shingle Pass Tuff; Darrough Felsite
Description: Welded and nonwelded silicic ash flow tuffs. Aside from alluvium, this unit covers more of Nevada than any other rock, with over 4,000 polygons representing it on this map. It is principally exposed in the central regions of the State. It locally includes thin units of air fall tuff and sedimentary rocks. It includes rocks mapped on the Washoe South, Lyon, Douglas, and Carson Counties maps as the Hartford Hill Rhyolite Tuff (now abandoned); on the Nye South map as the tuff of White Blotch Spring, the tuffs of Antelope Springs, and the tuff of Monotony Valley; in Lander County it is mapped as the Bates Mountain Tuff, Caetano Tuff, Edwards Creek Tuff, New Pass Tuff, tuff of Hall Creek, and the tuff of McCoy Mine; in Lander and Pershing Counties it is the Fish Creek Mountains Tuff; on both of the Nye County maps it is the Fraction Tuff; it also includes the Pancake Summit Tuff, Northumberland Tuff, Shingle Pass Tuff, some outcrops of Darrough Felsite shown to be Tertiary (other outcrops have been shown to be Mesozoic or Paleozoic), tuffs of Moores station, tuffs of Peavine Canyon, tuffs of the Pancake caldera complex, the Stone Cabin Formation, tuff of Saulsbury Wash, tuff of Kiln Canyon, the Tonopah Formation, tuffs of Hannapah, tuff of Bald Mountain, the Needles Range Formation, and the Calloway Well Formation on the Nye North map; in Esmeralda County it is the Kendall Tuff and latite; and in northern Nye and Lander Counties it is the Toiyabe Quartz Latite (now abandoned), and other unnamed units. It corresponds to unit Tt2 on the 1978 State map. It crops out in every county except Clark.
Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052. 
Minerals yearbook (1988) - Mining & Quarrying Trends: 31.
Wilson, W. E. (2009): The Round Mountain mine, Nye County, Nevada. Mineralogical Record: 40: 105-115.
Werschky, R. S. (2011). Kristallines Gold vom Round Mountain, Nevada, USA. Mineralien Welt. 22(4): 14-27.
Nevada Bureau of Mines and Geology Special Publication 31, Minerals of Nevada.