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Leta Lynn prospect, Twin Peaks, Steeple Rock District, Grant Co., New Mexico, USAi
Regional Level Types
Leta Lynn prospectProspect
Twin PeaksGroup of Peaks
Steeple Rock DistrictMining District
Grant Co.County
New MexicoState

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Lock Map
Latitude & Longitude (WGS84): 32° 55' 48'' North , 109° 2' 43'' West
Latitude & Longitude (decimal): 32.93005,-109.04535
GeoHash:G#: 9tf7qdex7
Locality type:Prospect
Köppen climate type:BSk : Cold semi-arid (steppe) climate
Nearest Settlements:
York557 (2011)15.2km
Duncan799 (2017)23.9km
Clifton3,685 (2017)27.0km
Virden137 (2017)27.3km
Buckhorn200 (2011)33.6km

A Fluorspar-Mn deposit/occurrence located about 1.3 km (4,200 feet) WNW of Twin Peaks. Discovered by Eugene Belcher in 1971.

Mineralization is irregular veins and pods. Ore control was fissures along a fault and alteration was argillization and silicification. Area structures include N20°W-trending fault which also extends SE across the Powell prospect.

Regions containing this locality

North America PlateTectonic Plate
Sonoran Desert, North AmericaDesert

Select Mineral List Type

Standard Detailed Strunz Dana Chemical Elements

Mineral List

3 valid minerals.

Detailed Mineral List:

Formula: CaF2
Reference: NMBMMR Memoir 34 Fluorspar in New Mexico
Formula: FeS2
Reference: MRDS database Dep. ID #10013498, MRDS ID #D009824.
Formula: SiO2
Reference: MRDS database Dep. ID #10013498, MRDS ID #D009824.
Reference: USGS Map I-1310-B Mineral Deposit Map Silver City 1x2 Quad

List of minerals arranged by Strunz 10th Edition classification

Group 2 - Sulphides and Sulfosalts
Group 3 - Halides
Group 4 - Oxides and Hydroxides
Unclassified Minerals, Rocks, etc.

List of minerals arranged by Dana 8th Edition classification

Group 2 - SULFIDES
AmBnXp, with (m+n):p = 1:2
Group 75 - TECTOSILICATES Si Tetrahedral Frameworks
Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si
Unclassified Minerals, Mixtures, etc.

List of minerals for each chemical element

O QuartzSiO2
F FluoriteCaF2
Si QuartzSiO2
S PyriteFeS2
Ca FluoriteCaF2
Fe PyriteFeS2

Regional Geology

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

Quaternary - Miocene
0 - 23.03 Ma

ID: 3185380
Cenozoic sedimentary rocks

Age: Cenozoic (0 - 23.03 Ma)

Lithology: Sedimentary rocks

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. [154]

Chattian - Rupelian
23.03 - 33.9 Ma

ID: 2769451
Lower-upper middle Tertiary basaltic andesites and andesites of the Mogollon Group

Age: Oligocene (23.03 - 33.9 Ma)

Stratigraphic Name: Mogollon Group

Description: Includes La Jara Peak Basaltic Andesite, Uvas Basaltic Andesite, basaltic andesites of Poverty Creek and Twin Peaks, Squirrel Springs Canyon Andesite, Razorback Basalt, Bear Springs Basalt, flows of Gila Flat, Salt Creek Formation, Middle Mountain Formation, and the Alum Mountain Group. Pre-Amalia-Tuff lavas in the Questa caldera are dominantly silicic andesites and dacites; elsewhere silicic lavas are a minor component of Tual.

Comments: Original map source: Green, G.N., Jones, G.E., and Anderson, O.J., 1997, The Digital Geologic Map of New Mexico in ARC/INFO Format: U.S. Geological Survey Open-File Report 97-0052, 9 p., scale 1:500,000.

Lithology: Major:{andesite,basaltic andesite,basalt}, Minor:{dacite}

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. [133]

Data and map coding provided by, used under Creative Commons Attribution 4.0 License


Sort by

Year (asc) Year (desc) Author (A-Z) Author (Z-A)
Biggerstaff, B.P. (1974), University of Texas M.S. thesis, 102 pp.
McAnulty, W.N. (1978), New Mexico Bureau of Mines and Mineral Resources Memorandum 34: 34.
USGS MRDS database (2005), Dep. ID #10013498, MRDS ID #D009824.

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