Lark group (Rattlesnake; Lucky Boy; Davis and Roseberry; Cinnabar group; Ivanhoe; Lark Quick), Ivanhoe District, Elko Co., Nevada, USAi
|Regional Level Types|
|Lark group (Rattlesnake; Lucky Boy; Davis and Roseberry; Cinnabar group; Ivanhoe; Lark Quick)||- not defined -|
|Ivanhoe District||Mining District|
|Latitude & Longitude (WGS84):||41° 8' 12'' North , 116° 35' 49'' West|
|Latitude & Longitude (decimal):||41.13693,-116.59711|
|USGS MRDS Record:||10045517|
|Köppen climate type:||BSk : Cold semi-arid (steppe) climate|
Deposit: Cinnabar-bearing fractures trending northerly through a glassy black tuff. Discovered in 1915, the group consists of 10 claims development consists of shallow workings which explore cinnabar-bearing fractures trending northrly through a glassy black tuff
Development: 10 claims
Ore(s): Fractures, Fissure Zones
Regions containing this locality
|North America Plate||Tectonic Plate|
Select Mineral List TypeStandard Detailed Strunz Dana Chemical Elements
Commodity ListThis is a list of exploitable or exploited mineral commodities recorded at this locality.
2 valid minerals.
Rock Types Recorded
Select Rock List TypeAlphabetical List Tree Diagram
Detailed Mineral List:
| ⓘ Cinnabar|
Reference: NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada; U.S. Geological Survey (2005) Mineral Resources Data System: U.S. Geological Survey, Reston, Virginia.
| ⓘ Opal|
Formula: SiO2 · nH2O
Reference: NBMG Bull 106 Geology and Mineral Resources of Elko County, Nevada
List of minerals arranged by Strunz 10th Edition classification
|Group 2 - Sulphides and Sulfosalts|
|Group 4 - Oxides and Hydroxides|
|ⓘ||Opal||4.DA.10||SiO2 · nH2O|
List of minerals arranged by Dana 8th Edition classification
|Group 2 - SULFIDES|
|AmXp, with m:p = 1:1|
|Group 75 - TECTOSILICATES Si Tetrahedral Frameworks|
|Si Tetrahedral Frameworks - SiO2 with H2O and organics|
|ⓘ||Opal||126.96.36.199||SiO2 · nH2O|
List of minerals for each chemical element
|H||ⓘ Opal||SiO2 · nH2O|
|O||ⓘ Opal||SiO2 · nH2O|
|Si||ⓘ Opal||SiO2 · nH2O|
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
2.588 - 23.03 Ma
|Cenozoic volcanic rocks|
Age: Neogene (2.588 - 23.03 Ma)
Stratigraphic Name: Columbia River Basalt
Comments: Columbia Plateau
Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529. 
|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.
Comments: Original map source: Crafford, A.E.J., 2007, Geologic Map of Nevada: U.S. Geological Survey Data Series 249, 1 CD-ROM, 46 p., 1 plate; Scale 1:250,000.
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.