SUPPORT US. If mindat.org is important to you, click here to donate to our Fall 2019 fundraiser!
Log InRegister
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreContact UsAdvertise on Mindat
Donate to MindatCorporate SponsorshipSponsor a PageSponsored PagesMindat AdvertisersAdvertise on Mindat
Learning CenterWhat is a mineral?The most common minerals on earthInformation for EducatorsMindat ArticlesThe ElementsBooks & Magazines
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
Mining CompaniesStatisticsUsersMineral MuseumsMineral Shows & EventsThe Mindat DirectoryDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryMineral Photography

Jumbo Mine, Kennecott, Nizina District, Valdez-Cordova Borough, Alaska, USA

This page is currently not sponsored. Click here to sponsor this page.
Key
Lock Map
Latitude & Longitude (WGS84): 61° 31' 18'' North , 142° 49' 14'' West
Latitude & Longitude (decimal): 61.52194,-142.82083
GeoHash:G#: bffmyp9p3
Locality type:Mine
Köppen climate type:ET : Tundra


The locality is in the Wrangell-Saint Elias National Park and Preserve.

Location: The Jumbo mine is in the cirque at the head of Jumbo Creek (MacKevett, 1970 [GQ 899]). It is at an elevation of about 5,800 feet, 3,000 feet west-northwest of Bonanza Peak (elevation 6983), and 3,400 feet northeast of elevation 5467. The mine is shown on the McCarthy C-5 quadrangle (1993 edition) in about the center of the N1/2 of section 15, T. 4 S., R. 14 E. of the Copper River Meridian. This is locality 92 of MacKevett (1976) and it is included by Cobb and MacKevett (1980) under the name 'Kennecott Copper Corp.'.

Geology: The Jumbo, Erie (MC083), Mother Lode (MC090), and Bonanza (MC093) mines, all on the ridge between McCarthy Creek and Kennicott and Root Glaciers, produced significant amounts of high-grade copper ore when they were operated by Kennecott Copper Corporation between 1911 and 1938. These mines developed several different orebodies but their underground workings were interconnected. Together they produced 4 million metric tons of ore with a grade of 13 percent copper. The estimated 536,000 tons of copper recovered was accompanied by the recovery of about 100 tons of silver (MacKevett and others, 1997). No other metals were of economic importance in these orebodies. Bateman and McLaughlin (1920) and Lasky (1929) provide important descriptions of the geology, mineralogy, and structure of these deposits. Cobb and MacKevett (1980) refer to the many Federal government publications, dating from the time of the Bonanza discovery in 1900, that contain information about them. MacKevett and others (1997) provide an excellent synthesis and interpretation of the structure, stratigraphy, economic geology, and geochemistry of these deposits. This record largely summarizes information provided by MacKevett and others (1997). The Jumbo mine produced 1,366,600 tons of ore containing 14.28 percent copper. The largest orebody, the Jumbo vein, produced 507,000 tons of ore containing 12.05 percent copper. The ore was worked from 20 levels between elevations of 1,036 and 1,755 meters. The Jumbo and other nearby orebodies are localized in the lower part of the Upper Triassic Chitistone Limestone. The base of the mineralization was usually about 15 to 45 meters stratigraphically above the contact of the Chitistone Limestone with the underlying Upper Triassic Nikolai Greenstone. The development of intertidal carbonate facies with stromatolites, bacterial mats, gypsum, and anhydrite in the lower Chitistone Limestone is one important control on the development and location of the orebodies. Steep, northeast-trending fissures up to 300 meters long are another important control on the location of the major orebodies. These fissures show minor displacement of bedding in the Chitistone Limestone and localize breccia and trangressive dolomite alteration. The breccia zones, thought by MacKevett and others (1997) to be early collapse breccia along solution-enlarged fissures, laterally envelop the orebodies and extend stratigraphically upward above them. The main Jumbo vein averaged about 110 meters in height, was between 0.6 and 18 meters in width, and can be followed along its northeastward-plunging base for more than 450 meters (Bateman and McLaughlin, 1920). The orebodies strike about N 40-60 E and dip near vertical. The massive ore near the base of the Jumbo vein was exceptionally high-grade. The orebody is bordered by copper-bearing disseminations and veinlets except at its base. The highest grade zone peripheral to the Jumbo vein contained 0.5 to 2.5 percent copper over a length 40 meters. Several splays to the Jumbo vein, subparallel veins, bedding-parallel veins to 0.3 meters thick, and small masses measuring about 10 by 15 meters in plan and 15 meters high had minor production. Typically the large high-grade copper deposits of the area, like the Mother Lode vein, contain many minerals in the Cu2S-CuS system. Chalcocite and djurleite are abundant along with minor amounts of covellite, bornite, chalcopyrite, digenite, anilite, luzonite, idaite, malachite, azurite, chalcanthite, and orpiment. Other minerals reported by Bateman and McLaughlin (1920) in minor or trace amounts, include tennantite, antlerite, sphalerite, galena, pyrite, and copper arsenates. Enargite reported by Bateman and McLaughlin was not identified by MacKevett and others (1997). Although the Chitistone Limestone-hosted, copper-rich ores are mostly chalcocite and djurleite, remnant clots of earlier minerals allow the determination of the mineral paragenesis. Early pyrite, now found only in traces, was replaced by chalcopyrite, which in turn was replaced by bornite and minor covellite. Temperatures of sulfide deposition fell during these stages from near 200 to 150 degrees centigrade. The main-stage ore minerals, chalcocite and djurleite, made up 95 percent of the ore and were deposited at temperatures of 90 +/- 10 degrees centigrade. Later, oxidized ore fluids overwhelmed reductants in the host rock and chalcocite was partly replaced by anilite and covellite and finally by malachite and azurite. The common alteration at the Jumbo and other Chitistone Limestone-hosted, high-grade copper deposits in the area is trangressive dolomitization. Dolomite replacement is approximately coincident with the breccia zones that laterally surround the orebodies and extend vertically above them. The replacement dolomite is coarser and lighter gray than the original dolostone and it lacks any evidence of bedding (Armstrong and MacKevett, 1982; MacKevett and others, 1997). Some Jumbo breccias contain ore minerals cementing limestone and dolomite, but calcite cement is common. A few breccias contain stratified, generally reddish, sandy, limy material. The mineralogy and geochemistry of the high-grade copper deposits combined with fluid inclusion and stable isotope data, indicate that the high-grade copper ores were deposited by reactions between oxidized copper-rich brines which moved through Nikolai Greenstone and sulfur-rich fluids derived from the thermal reduction of gypsum in the presence of organic matter in the lower part of the Chitistone Limestone. The migration of the oxidized copper-rich brines to the site of deposition is thought to have accompanied regional deformation and low-grade metamorphism in the Late Jurassic or Early Cretaceous (MacKevett and others, 1997). Related copper-bearing minerals were deposited in the underlying Nikolai Greenstone at about 112 Ma (Silberman and others, 1980).

Workings: The ore was worked from 20 levels between elevations of 1,036 and 1,755 meters. The underground workings at the Jumbo mine are interconnected with those at the Erie (MC083), Mother Lode (MC090), and Bonanza (MC093) mines.

Age: Cretaceous? The migration of the oxidized copper-rich brines to the site of deposition is thought to have accompanied regional deformation and low-grade metamorphism in the Late Jurassic or Early Cretaceous (MacKevett and others, 1997). Related copper-bearing minerals were deposited in the underlying Nikolai Greenstone at about 112 Ma (Silberman and others, 1980).
Alteration: The common alteration at the Jumbo and other Chitistone Limestone-hosted, high-grade copper deposits in the area is trangressive dolomitization. Dolomite replacement is approximately coincident with the breccia zones that laterally surround the orebodies and extend vertically above them. The replacement dolomite is coarser and lighter gray than the original dolostone and it lacks any evidence of bedding (Armstrong and MacKevett, 1982; MacKevett and others, 1997). Some Jumbo breccias contain ore minerals cementing limestone and dolomite, but calcite cement is common. A few breccias contain stratified, generally reddish, sandy, limy material. Oxidation of deposits is not related to the present land surface and practically the entire deposit has been partially oxidized, even in the deepest levels of mine.

Production: The Jumbo mine produced 1,366,600 tons of ore containing 14.28 percent copper. The largest orebody, the Jumbo vein, produced 507,000 tons of ore containing 12.05 percent copper.

Commodities (Major) - Ag, Cu
Development Status: Yes; large
Deposit Model: Kennecott-type copper deposit (after MacKevett and others, 1997)

Select Mineral List Type

Standard Detailed Strunz Dana Chemical Elements

Commodity List

This is a list of exploitable or exploited mineral commodities recorded at this locality.


Mineral List


21 valid minerals.

Detailed Mineral List:

Anilite
Formula: Cu7S4
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Antlerite
Formula: Cu3(SO4)(OH)4
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Azurite
Formula: Cu3(CO3)2(OH)2
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Bornite
Formula: Cu5FeS4
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Calcite
Formula: CaCO3
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Chalcanthite
Formula: CuSO4 · 5H2O
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Chalcocite
Formula: Cu2S
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Chalcopyrite
Formula: CuFeS2
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
'commodity:Copper'
Formula: Cu
Reference: From USGS MRDS database
Covellite
Formula: CuS
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Digenite
Formula: Cu9S5
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Djurleite
Formula: Cu31S16
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Dolomite
Formula: CaMg(CO3)2
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Enargite
Formula: Cu3AsS4
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Galena
Formula: PbS
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Idaite
Formula: Cu5FeS6
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Luzonite
Formula: Cu3AsS4
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Malachite
Formula: Cu2(CO3)(OH)2
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Orpiment
Formula: As2S3
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Pyrite
Formula: FeS2
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
'commodity:Silver'
Formula: Ag
Reference: From USGS MRDS database
Sphalerite
Formula: ZnS
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.
Tennantite
Formula: Cu6[Cu4(Fe,Zn)2]As4S13
Reference: U.S. Geological Survey, 2008, Alaska Resource Data File (ARDF): U.S. Geological Survey Open-File Report 2008-1225.

List of minerals arranged by Strunz 10th Edition classification

Group 2 - Sulphides and Sulfosalts
'Anilite'2.BA.10Cu7S4
'Bornite'2.BA.15Cu5FeS4
'Chalcocite'2.BA.05Cu2S
'Chalcopyrite'2.CB.10aCuFeS2
'Covellite'2.CA.05aCuS
'Digenite'2.BA.10Cu9S5
'Djurleite'2.BA.05Cu31S16
'Enargite'2.KA.05Cu3AsS4
'Galena'2.CD.10PbS
'Idaite'2.CB.15aCu5FeS6
'Luzonite'2.KA.10Cu3AsS4
'Orpiment'2.FA.30As2S3
'Pyrite'2.EB.05aFeS2
'Sphalerite'2.CB.05aZnS
'Tennantite'2.GB.05Cu6[Cu4(Fe,Zn)2]As4S13
Group 5 - Nitrates and Carbonates
'Azurite'5.BA.05Cu3(CO3)2(OH)2
'Calcite'5.AB.05CaCO3
'Dolomite'5.AB.10CaMg(CO3)2
'Malachite'5.BA.10Cu2(CO3)(OH)2
Group 7 - Sulphates, Chromates, Molybdates and Tungstates
'Antlerite'7.BB.15Cu3(SO4)(OH)4
'Chalcanthite'7.CB.20CuSO4 · 5H2O

List of minerals arranged by Dana 8th Edition classification

Group 2 - SULFIDES
AmBnXp, with (m+n):p = 2:1
Anilite2.4.7.5Cu7S4
Chalcocite2.4.7.1Cu2S
Digenite2.4.7.3Cu9S5
Djurleite2.4.7.2Cu31S16
AmBnXp, with (m+n):p = 3:2
Bornite2.5.2.1Cu5FeS4
AmXp, with m:p = 1:1
Covellite2.8.12.1CuS
Galena2.8.1.1PbS
Sphalerite2.8.2.1ZnS
AmBnXp, with (m+n):p = 1:1
Chalcopyrite2.9.1.1CuFeS2
Idaite2.9.14.1Cu5FeS6
AmBnXp, with (m+n):p = 2:3
Orpiment2.11.1.1As2S3
AmBnXp, with (m+n):p = 1:2
Pyrite2.12.1.1FeS2
Group 3 - SULFOSALTS
ø = 4
Enargite3.2.1.1Cu3AsS4
Luzonite3.2.2.1Cu3AsS4
3 <ø < 4
Tennantite3.3.6.2Cu6[Cu4(Fe,Zn)2]As4S13
Group 14 - ANHYDROUS NORMAL CARBONATES
A(XO3)
Calcite14.1.1.1CaCO3
AB(XO3)2
Dolomite14.2.1.1CaMg(CO3)2
Group 16a - ANHYDROUS CARBONATES CONTAINING HYDROXYL OR HALOGEN
Azurite16a.2.1.1Cu3(CO3)2(OH)2
Malachite16a.3.1.1Cu2(CO3)(OH)2
Group 29 - HYDRATED ACID AND NORMAL SULFATES
AXO4·xH2O
Chalcanthite29.6.7.1CuSO4 · 5H2O
Group 30 - ANHYDROUS SULFATES CONTAINING HYDROXYL OR HALOGEN
(AB)m(XO4)pZq, where m:p>2:1
Antlerite30.1.12.1Cu3(SO4)(OH)4

List of minerals for each chemical element

HHydrogen
H AntleriteCu3(SO4)(OH)4
H AzuriteCu3(CO3)2(OH)2
H ChalcanthiteCuSO4 · 5H2O
H MalachiteCu2(CO3)(OH)2
CCarbon
C AzuriteCu3(CO3)2(OH)2
C CalciteCaCO3
C DolomiteCaMg(CO3)2
C MalachiteCu2(CO3)(OH)2
OOxygen
O AntleriteCu3(SO4)(OH)4
O AzuriteCu3(CO3)2(OH)2
O CalciteCaCO3
O ChalcanthiteCuSO4 · 5H2O
O DolomiteCaMg(CO3)2
O MalachiteCu2(CO3)(OH)2
MgMagnesium
Mg DolomiteCaMg(CO3)2
SSulfur
S AniliteCu7S4
S AntleriteCu3(SO4)(OH)4
S BorniteCu5FeS4
S ChalcanthiteCuSO4 · 5H2O
S ChalcociteCu2S
S ChalcopyriteCuFeS2
S CovelliteCuS
S DigeniteCu9S5
S DjurleiteCu31S16
S EnargiteCu3AsS4
S GalenaPbS
S IdaiteCu5FeS6
S LuzoniteCu3AsS4
S OrpimentAs2S3
S PyriteFeS2
S SphaleriteZnS
S TennantiteCu6[Cu4(Fe,Zn)2]As4S13
CaCalcium
Ca CalciteCaCO3
Ca DolomiteCaMg(CO3)2
FeIron
Fe BorniteCu5FeS4
Fe ChalcopyriteCuFeS2
Fe IdaiteCu5FeS6
Fe PyriteFeS2
CuCopper
Cu AniliteCu7S4
Cu AntleriteCu3(SO4)(OH)4
Cu AzuriteCu3(CO3)2(OH)2
Cu BorniteCu5FeS4
Cu ChalcanthiteCuSO4 · 5H2O
Cu ChalcociteCu2S
Cu ChalcopyriteCuFeS2
Cu CovelliteCuS
Cu DigeniteCu9S5
Cu DjurleiteCu31S16
Cu EnargiteCu3AsS4
Cu IdaiteCu5FeS6
Cu LuzoniteCu3AsS4
Cu MalachiteCu2(CO3)(OH)2
Cu TennantiteCu6[Cu4(Fe,Zn)2]As4S13
ZnZinc
Zn SphaleriteZnS
AsArsenic
As EnargiteCu3AsS4
As LuzoniteCu3AsS4
As OrpimentAs2S3
As TennantiteCu6[Cu4(Fe,Zn)2]As4S13
PbLead
Pb GalenaPbS

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 Macrostrat.org

Late Triassic
201.3 - 237 Ma



ID: 640719
Sedimentary; Carbonate

Age: Late Triassic (201.3 - 237 Ma)

Description: Okhotsk, Bering Sea, Pacific Alaska, Alaska Range

Comments: Orogen, magmatic arc/suite; Wilson & Hults, unpublished compilation, 2007-08

Lithology: Limestone, dolostone, shale, evaporites, chalk; carbonate reefs or metamorphosed equivalent

Reference: J.C. Harrison, M.R. St-Onge, O.V. Petrov, S.I. Strelnikov, B.G. Lopatin, F.H. Wilson, S. Tella, D. Paul, T. Lynds, S.P. Shokalsky, C.K. Hults, S. Bergman, H.F. Jepsen, and A. Solli. Geological map of the Arctic. doi:10.4095/287868. Geological Survey of Canada Map 2159A. [2]

Triassic
201.3 - 251.902 Ma



ID: 3191593
Mesozoic volcanic rocks

Age: Triassic (201.3 - 251.902 Ma)

Lithology: Mafic volcanic 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]

Carnian - Late Triassic
227 - 237 Ma



ID: 1713413
Chitistone and Nizina Limestones and Kamishak Formation

Age: Late Triassic (227 - 237 Ma)

Stratigraphic Name: Chitistone Limestone; Nizina Limestone; Kamishak Formation

Description: Both have marked lateral changes in thickness. Lowest Chitistone: dolomite algal-mat chips, stromatolites and evaporites. Upper Chitistone: diverse limestone including lime mudstones, wackestone, packstone, and grainstone. Nizina: diverse limestone with subordinate chert nodules, lenses,and coalescing masses. Probable correlatives of Triassic carbonate rocks in Nabesna Quad and south-central Alaska

Lithology: Sedimentary

Reference: Wilson, F.H., Hults, C.P., Mull, C.G, and Karl, S.M. (compilers). Geologic map of Alaska. doi: 10.3133/sim3340. U.S. Geological Survey Scientific Investigations Map 3340, pamphlet 196. [21]

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

References

Sort by

Year (asc) Year (desc) Author (A-Z) Author (Z-A)
Armstrong, A.K., and MacKevett, E.M., Jr., 1982, Stratigraphy and diagenetic history of the lower part of the Triassic Chitistone Limestone, Alaska: U.S. Geological Survey Professional Paper 1212-A, 26 p.
Bateman, A.M., and McLaughlin, D.H., 1920, Geology of the ore deposits of Kennecott, Alaska: Economic Geology, v. 15, p. 1-80.
Cobb, E.H., and MacKevett, E.M., Jr., 1980, Summaries of data on and lists of references to metallic and selected nonmetallic mineral deposits in the McCarthy quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-885, 156 p.
Lasky, S.G., 1929, Transverse faults at Kennecott and their relation to the main fault systems: American Institute of Mining and Metallurgical Engineers Transactions, v. 85, p. 303-317.
MacKevett, E.M., Jr., 1970, Geologic map of the McCarthy C-5 quadrangle, Alaska: U.S. Geological Survey Geologic Quadrangle Map GQ-899, 1 sheet, scale 1:63,360.
MacKevett, E.M., Jr., 1976, Mineral deposits and occurrences in the McCarthy quadrangle, Alaska: U.S. Geological Survey Miscellaneous Field Studies Map MF-773-B, 2 sheets, scale 1:250,000.
MacKevett, E.M., Jr., Cox, D.P., Potter, R.W., III, and Silberman, M.L., 1997, Kennecott-type deposits in the Wrangell Mountains, Alaska--High-grade copper ores near a basalt-limestone contact, in Goldfarb, R.J., and Miller, L.D., eds., Mineral deposits of Alaska: Economic Geology Monograph 9, p. 66-89.
Silberman, M.L., MacKevett, E.M., Jr., Connor, C.L., and Mathews, A., 1980, Metallogenic and tectonic significance of oxygen isotope data and whole-rock potassium-argon ages of Nikolai Greenstone, McCarthy quadrangle, Alaska: U.S. Geological Survey Open-File Report 80-2019, 31 p.


This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.
 
Mineral and/or Locality  
Mindat.org is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Public Relations by Blytheweigh.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2019, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: December 10, 2019 07:57:22 Page generated: October 31, 2018 18:08:47
Go to top of page