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Fortuna Mine (La Fortuna Mine), Barry M. Goldwater Air Force Range, Fortuna Mining District (La Fortuna Mining District), Gila Mts, Yuma Co., Arizona, USAi
Regional Level Types
Fortuna Mine (La Fortuna Mine)Mine
Barry M. Goldwater Air Force RangeMountain Range
Fortuna Mining District (La Fortuna Mining District)Mining District
Gila MtsMountain Range
Yuma Co.County
ArizonaState
USACountry

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Key
Latitude & Longitude (WGS84):
32° 33' 6'' North , 114° 19' 48'' West
Latitude & Longitude (decimal):
Locality type:
Köppen climate type:
Nearest Settlements:
PlacePopulationDistance
Fortuna Foothills26,265 (2011)14.1km
Wellton2,936 (2017)21.8km
El Prado Estates504 (2017)24.8km
Buckshot153 (2017)25.4km
Rancho Mesa Verde625 (2017)30.8km


A former underground Au-Ag-Cu-Fe mine located on 7 original claims plus 5 additional claims when Elan took over operations, in sec. 16 and North-central sec. 21, T.10S., R.20W. (protracted), at the western base of the Gila Mountains, at 775 feet of altitude, about 20 miles from Wellton and 28 miles SE of Yuma, on a military reservation. Started in the early 1890's (1892-1895) and closed in 1904. Reopened 1913-1914 and 1924-1926. Owned at times, or in part, by La Fortuna Gold Mining and Milling Co. Charles D. Lane of Angels Camp (1896- ); Fortuna Mines Corp.; Elan Mining Co. (1924- ); McDaniels & Harrison; Enderton; Holmes & Nichelson; Wish Mining & Milling Co.; Maitland; Messrs. Charles Thomas, William Holbert + 2 others; and, Burton.

The mine is on a narrow, dissected pediment between foothill ridges. The prevailing rocks are Precambrian or later schist and gneiss, intruded by large masses of granite and amphibolite and numerous dikes of pegmatite and aplite. The schist, and part of the gneiss, are of sedimentary origin. These rocks strike West or SW, transverse to the trend of the range, and dip steeply southward. Mineralization is free gold with silver in rounded grains and as thin irregular veinlets with limonite or pyrite, with traces of copper, in fractured quartz in a branching, chimney-like orebody along a fissure zone in Mesozoic schist. The orebody strikes S.40ºW. and dips 70ºSE. It outcrops in 2 branches. One is 20 feet long by 12 feet wide & the other is 30 feet long by 5 feet wide. These join at the 500 level, forming an orebody approximately 100 feet long by 1½ to 12 feet wide. The orebody is lost by fault about 800 from surface and only a small segment was found between the 900 and 1100 levels. Gold-bearing quartz is coarse-grained, vitreous, pale straw-colored & locally stained with malachite. Wall rocks are carbonatized and silicified. There are many branching and intersecting faults.

Workings include 2 inclined shafts connecting with several hundred feet of drifts, stopes, etc. The older, 2-compartment shaft is 350 feet deep & inclines 60º in a N.34ºE. direction. The newer shaft (lower shaft)(1900-1901) is a deep shaft at about 1000 feet deep and inclines 58º in a S.54ºE. direction and was worked mainly from 1896 through 1904, and sporadically thereafter into 1941. A 20-stamp mill was erected on the property. Total estimated and recorded production would be some 213,000 tons of ore averaging about 0.63 oz. Au/T, 0.05 oz. Ag/T, and a few pounds of copper. Assay data: Au averaged $15 to $16 per ton and 890 fine. This equates to $2,587,987 in Au bullion (Sep 1896 - Dec 1904), plus another $25,000 of Au until ultimate closure (period values).

Regions containing this locality

North America PlateTectonic Plate
Sonoran Desert, North AmericaDesert

Select Mineral List Type

Standard Detailed Strunz Dana Chemical Elements

Mineral List


6 valid minerals.

Detailed Mineral List:

Andalusite
Formula: Al2(SiO4)O
Habit: Prismatic, long, tabular, radiating
Description: Occurs as crystals in gray, speckled, quartz-biotite schist adjacent to the vein.
Reference: Wilson, E.D. (1933), AZ Bur. Mines Bull. 134: 43, 189-199.
Epidote
Formula: {Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Description: Occurs in black schist.
Reference: Wilson, E.D. (1933), AZ Bur. Mines Bull. 134: 43, 189.
'Garnet Group'
Formula: X3Z2(SiO4)3
Colour: Brown
Description: Occurs as small garnets.
Reference: Wilson, E.D. (1933), AZ Bur. Mines Bull. 134: 43, 189.
Gold
Formula: Au
Description: Free gold with silver in rounded grains within converging hair-like cracks & as thin, irregular veinlets within limonite or pyrite.
Reference: Keith, Stanton B. (1978) State of Arizona Bureau of Geology and Mineral Technology, Geol. Sur. Br. Bull. 192, Index of Mining Properties in Yuma Co., Arizona: 150 (Table 4); Blake (1897); Blake (1898); Wilson, E.D. (1933), AZ Bur. Mines Bull. 134: 43, 189; Wilson, E.D. (1934)(revised 1967): 152-155; Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 235; Arizona Bureau of Mines file data.
Hematite
Formula: Fe2O3
Description: Occurs as small, shiny masses in schist near its hanging wall.
Reference: Wilson, E.D. (1933), AZ Bur. Mines Bull. 134: 43, 189.
Hematite var: Specularite
Formula: Fe2O3
Description: Occurs as small, shiny masses in schist near its hanging wall.
Reference: Wilson, E.D. (1933), AZ Bur. Mines Bull. 134: 43, 189.
'Hornblende'
Description: Occurs in vein wall rocks.
Reference: Wilson, E.D. (1933), AZ Bur. Mines Bull. 134: 43, 189.
'Limonite'
Formula: (Fe,O,OH,H2O)
Reference: Keith, Stanton B. (1978) State of Arizona Bureau of Geology and Mineral Technology, Geol. Sur. Br. Bull. 192, Index of Mining Properties in Yuma Co., Arizona: 150 (Table 4); Blake (1897); Blake (1898); Wilson, E.D. (1933): 189-199; Wilson, E.D. (1934)(revised 1967): 152-155; Arizona Bureau of Mines file data.
Malachite
Formula: Cu2(CO3)(OH)2
Description: Occurs as stains.
Reference: Wilson, E.D. (1934)(revised 1967), AZ Bur. Mines Bull. 137: 152: 152-155.
Pyrite
Formula: FeS2
Reference: Keith, Stanton B. (1978) State of Arizona Bureau of Geology and Mineral Technology, Geol. Sur. Br. Bull. 192, Index of Mining Properties in Yuma Co., Arizona: 150 (Table 4); Blake (1897); Blake (1898); Wilson, E.D. (1933): 189-199; Wilson, E.D. (1934)(revised 1967): 152-155; Arizona Bureau of Mines file data.

List of minerals arranged by Strunz 10th Edition classification

Group 1 - Elements
Gold1.AA.05Au
Group 2 - Sulphides and Sulfosalts
Pyrite2.EB.05aFeS2
Group 4 - Oxides and Hydroxides
Hematite4.CB.05Fe2O3
var: Specularite4.CB.05Fe2O3
Group 5 - Nitrates and Carbonates
Malachite5.BA.10Cu2(CO3)(OH)2
Group 9 - Silicates
Andalusite9.AF.10Al2(SiO4)O
Epidote9.BG.05a{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Unclassified Minerals, Rocks, etc.
'Garnet Group'-X3Z2(SiO4)3
'Hornblende'-
'Limonite'-(Fe,O,OH,H2O)

List of minerals arranged by Dana 8th Edition classification

Group 1 - NATIVE ELEMENTS AND ALLOYS
Metals, other than the Platinum Group
Gold1.1.1.1Au
Group 2 - SULFIDES
AmBnXp, with (m+n):p = 1:2
Pyrite2.12.1.1FeS2
Group 4 - SIMPLE OXIDES
A2X3
Hematite4.3.1.2Fe2O3
Group 16a - ANHYDROUS CARBONATES CONTAINING HYDROXYL OR HALOGEN
Malachite16a.3.1.1Cu2(CO3)(OH)2
Group 52 - NESOSILICATES Insular SiO4 Groups and O,OH,F,H2O
Insular SiO4 Groups and O, OH, F, and H2O with cations in [4] and >[4] coordination
Andalusite52.2.2b.1Al2(SiO4)O
Group 58 - SOROSILICATES Insular, Mixed, Single, and Larger Tetrahedral Groups
Insular, Mixed, Single, and Larger Tetrahedral Groups with cations in [6] and higher coordination; single and double groups (n = 1, 2)
Epidote58.2.1a.7{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Unclassified Minerals, Mixtures, etc.
'Garnet Group'-X3Z2(SiO4)3
Hematite
var: Specularite
-Fe2O3
'Hornblende'-
'Limonite'-(Fe,O,OH,H2O)

List of minerals for each chemical element

HHydrogen
H Limonite(Fe,O,OH,H2O)
H MalachiteCu2(CO3)(OH)2
H Epidote{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
CCarbon
C MalachiteCu2(CO3)(OH)2
OOxygen
O Limonite(Fe,O,OH,H2O)
O MalachiteCu2(CO3)(OH)2
O AndalusiteAl2(SiO4)O
O Garnet GroupX3Z2(SiO4)3
O Hematite (var: Specularite)Fe2O3
O Epidote{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
O HematiteFe2O3
AlAluminium
Al AndalusiteAl2(SiO4)O
Al Epidote{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
SiSilicon
Si AndalusiteAl2(SiO4)O
Si Garnet GroupX3Z2(SiO4)3
Si Epidote{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
SSulfur
S PyriteFeS2
CaCalcium
Ca Epidote{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
FeIron
Fe PyriteFeS2
Fe Limonite(Fe,O,OH,H2O)
Fe Hematite (var: Specularite)Fe2O3
Fe Epidote{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Fe HematiteFe2O3
CuCopper
Cu MalachiteCu2(CO3)(OH)2
AuGold
Au GoldAu

References

Sort by

Year (asc) Year (desc) Author (A-Z) Author (Z-A)
Blake, W.P. (1897), The Fortuna gold mine, Engineering and Mining Journal: 63: 26.
Blake, W.P. (1898) Distribution of metallic wealth in Arizona, in Report of the Governor of Arizona to the Secretary of the Interior for fiscal year ending June 30, 1898: Washington, D.C.: 19-86.
Wilson, E.D. (1933) Geology and Mineral Deposits of Southern Yuma County, Arizona. Arizona Bureau of Mines Bulletin 134: 43, 189-199.
Wilson, E.D., Cunningham, J.B., and Butler, G.M. (1934), Arizona Lode Gold Mines and Gold Mining (revised 1967), Arizona Bureau of Mines Bull. 137: 152-155.
Elsing, M.J. and Heineman, E.S. (1936) Arizona Metal Production, Arizona Bureau of Mines Bulletin 140: 104.
Keith, Stanton B. (1978) State of Arizona Bureau of Geology and Mineral Technology, Geol. Sur. Br. Bull. 192, Index of Mining Properties in Yuma Co., Arizona: 150 (Table 4).
Sawyer, M.B., Gurmendi, A.C., Daley, M.R., and Howell, S.B. (1992) Principal Deposits of Strategic and Critical Minerals in Arizona, U.S. Bureau of Mines Special Publication, 334 pp.
Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd. ed.: 235.
Arizona Bureau of Mines file data.
MRDS database Dep. ID #10027250, MRDS ID #M002626; and, Dep. ID file #10113627, MAS ID #0040270197.

USGS MRDS Record:10027250
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