Melco

Sediment-hosted gold deposit in Utah, U.S.A.

Geologic information

CountryU.S.A.
State or provinceUtah
Geographic location:40°35'12"N, 112°9'34"W
(-112.159444, 40.586667)
(click for info)
SubtypeCarlin
Deposit size
Length0.7km
Width0.1km
Thickness60m
Area0.05sq km
Deposit features
Dikes or sills
Fault zone
Ore breccia
Deposit age geologicMesozoic (?); Oligocene–Eocene
Deposit clusterBingham porphyry system
Geochemical indicatorsAu, As, Sb, Hg, Tl, Ba
Intrusive rockunaltered latite porphyry (2.5 km to W)
Intrusive rock ageTertiary (?) Ma
Ore bearing unitPermian Kirkman-Diamond Creek Fm. and Freeman Peak Fm.)
Tectonic settingNorth-American craton, platform at rifted western margin
Minerals
Gold-bearing minerals:
Ore minerals:
Gangue minerals:
Alteration
Associated depositsCu-Au-Mo porphyry (Bingham); Cu-Au skarn (Carr Fork); Pb-Zn-Ag replacement and vein; sediment-hosted Au
Geologic map unit-112.159444444444, 40.5866666666667
Nearby scientific dataFind additional scientific data near this location

Economic information

Statusinactive
Discovery date1986
Startup date1988
Gold particle size≤1 to 100
Operation types
Open pit
Crushing and milling
Heap leach
Production tonnage15.7tonnes
Production years1989–2001
Total tonnage15.7tonnes
Contained gold37.7 tonnes
Recovery Au85%
Source of tonnage, gradeKrahulek (2010)

Silver grade

SilverUnitsCriteria
0g/tAll ore in deposit

Gold grade

GoldReservesResourcesUnitsCriteria
2.4g/tProduced ore (grams per tonne)
2.4g/tAll ore in deposit

Gold cut-off grades

ReservesResourcesUnitsCriteria

Reserves and Resources

Mining methodEstimate typeTonnageCriteria

Reference information

Comments

Mined, depleted 1989–2001. Oxidation extends to depth >200 m. The deposit remains open beyond depth of 300 m. Heap leaching of gold in minor amounts continues in 2009. Au:Ag=50:1 (Krahulek, 2010). Waste:ore=9:1 (Gunter and Austin (1997). Gold mineralization confined to NE-trending steeply-dipping anastomosing fault and breccia zone near structurally complex contact of Kirkman-Diamond Creek and Freeman Peak Formations. 85% gold recovery indicates average gold extraction.

References

Babcock, R.S., Jr., Ballantyne, G.H., and Phillips, C.H., 1997, Summary of the geology of the Bingham district, Utah, in John, D.A., and Ballantyne, G.H., eds, Geology and ore deposits of the Oquirrh and Wasatch mountains, Utah: Society of Economic Geologists Guidebook Series, v. 29, p. 113–132.
Briggs, D.F., 2006, Mining operations report, version 2005: Unpublished.
Cunninham, C.G., Austin, G.W., Naeser, C.W., Rye, R.O., Ballantyne, G.H., Stamm, R.G., and Barker, C.E., 2004, Formation of paleothermal anomaly and disseminated gold deposits associated with the Bingham Canyon porphyry Cu-Au-Mo system, Utah: Economic Geology, v. 99, p. 789–806.
Gibson, T.R., 2009, Discovery of the Barneys Canyon and Melco gold deposits, Salt Lake county, Utah: Utah Geological Association Publication 38, p. 133–142.
Gunter, W.L., and Austin, G.W., 1996, The geology of gold deposits in the Barneys Canyon project area, Salt Lake City, Utah, in Green, S.M., and Struhsacker, E., eds., Geology and ore deposits of the American Cordillera: Reno, Geological Society of Nevada, Field Trip Guidebook Compendium, p. 43–58.
Gunter, W.L., and Austin, G.W., 1997, Geology of the Melco gold deposit, Oquirrh Mountains, Utah, in John, D.A., and Ballantyne, G.H., eds, Geology and ore deposits of the Oquirrh and Wasatch mountains, Utah: Society of Economic Geologists Guidebook Series, v. 29, p. 227–240.
Krahulek, K., 2010, Sedimentary rock-hosted gold and silver deposits of the northeastern Basin and Range, Utah, in Steiniger, R., and Pennel, B., eds., Great Basin evolution and metallogeny: DEStech Publications, Inc, Geological Society of Nevada, Symposium 2010 Proceedings, p. 31–62.
Laes, D.Y.M., Krahulec, K.A., and Ballantyne, G.H., 1997, Geologic map of the Oquirrh Mountains, in John, D.A., and Ballantyne, G.H., eds, Geology and ore deposits of the Oquirrh and Wasatch mountains, Utah: Society of Economic Geologists Guidebook Series, v. 29, 1 sheet, scale 1:62,500.
Mindat.org, 1993, Melco deposit, Barney’s Canyon, Bingham district, Oquirrh Mts., Salt Lake: 1 p., last accessed July 26, 2011, at http://www.mindat.org/loc-68232.html.