Garnet Hill, Ely, Robinson District, White Pine Co., Nevada, USA
|Latitude & Longitude (WGS84):||39° 18' North , 114° 56' West|
|Latitude & Longitude (decimal):||39.30000,-114.93333|
|Köppen climate type:||BSk : Cold semi-arid (steppe) climate|
Garnet Fields recreational site near the town of Ruth. A flow banded rhyolite with lithophysae. Sec 1, 2, 12 T16N R62E.
The garnet from here is almandine and not spessartine, although almost all garnets from this location have been incorrectly labeled spessartine by collectors. Repeated chemical analyses have shown the Fe to Mn ratio is consistently about 2.5 Fe to 1 Mn. See summaries with chemical analyses at Hollabaugh and Purcell (1987); Pabst (1938).
10 valid minerals. 1 erroneous literature entry.
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 Mississippian - Late Devonian|
346.7 - 382.7 Ma
|Foreland Basin Assemblage - Siltstone, limestone, shale, and sandstone|
Age: Paleozoic (346.7 - 382.7 Ma)
Description: Unit crops out across all of eastern Nevada, generally east of 116 west longitude. It includes rocks mapped primarily as Pilot Shale, Joana Limestone, Chainman Shale, and their equivalents. This also includes the Tripon Pass Limestone in Elko County, the Cockalorum Wash Formation (now abandoned) in northern Nye County, the Mercury and Bristol Pass Limestones in Lincoln County, and some of the rocks mapped as Monte Cristo Limestone in Clark County. While it may be desirable to separate out the different lithologies, they are not well enough differentiated at this regional map scale. The Chainman, Joana and Pilot are grouped in White Pine County, and the Joana and Pilot are grouped in Elko County. The Pilot Shale lies depositionally (both conformably and disconformably) on Upper Devonian carbonate rocks (Dc) and signals a major change in the depositional setting across most of the carbonate platform which has long been attributed to the onset of deformation attributed to the Antler orogeny. The Pilot Shale is generally recognized as carbonaceous shale, overlain by the cliff-forming Joana Limestone. Siliciclastic quartz-bearing grit, chert, quartz sand, and siltstone in a calcareous matrix become increasingly common as the section turns into the Chainman Shale and other equivalent siliciclastic rocks. The sequence is interrupted by disconformities in a number of places, but structural disruption and poor age control hinder determination of the nature of the contacts between the distinct lithologies. Unit MDcl is overlain by unit IPMcl, but there are places where the age and distinction between the units is poorly constrained. In southernmost Nevada, in Clark and southeastern White Pine Counties, Devonian carbonate is overlain by Mississippian carbonate (Mc) with little or no intervening Pilot Shale equivalent and few overlying siliciclastic rocks with western-derived source material. North and west of the area of exposure of unit MDcl, fault-bounded slivers of Lower Mississippian and Upper Devonian platform margin and slope facies rocks with siliciclastic horizons have been grouped into unit MDst and separated from unit MDcl.
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.