On alunite and diaspore from the Rosita Hills

Cross, C. W.

doi:10.2475/ajs.s3-41.246.466

Cited by 3 publications

(10 citation statements)

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“…The best-known mine about this time, or a little later, was the Santa Rita del Cobre, which was worked probably about the middle of the thirties and produced ore yielding 75 per cent of copper. 1 After the Gadsden purchase, made in 1853, Americans, including Poston, Mowry, and others, began to enter the region, eastern capital was enlisted, and more prominent mining settlements were made in the Santa Rita and Patagonia mountains as early as 1855, about which time the historic Mowry mine was located. In 1857 the country between the boundary and Calabasas was reported by the Emory Boundary Survey to be full of prospectors from California.…”

Section: Mstory Of Mining and Present Conditionsmentioning

confidence: 99%

“…This revival, besides involving the reoccupation of most of the old and the exploitation of many new properties, included the opening on the east slope of the Santa Rita Mountains of a new lead and gold region, comprising the present Wrightson and Greaterville districts, the latter of which soon produced considerable placer gold. 1 The completion of the Southern Pacific transcontinental railroad in 1879 and that of the Atlantic & Pacific in 1883 were potent factors in opening the Territory to immigration and capital. Before the advent of the railroad ore that would not yield $100 to the ton was passed by as worthless.…”

Section: Mstory Of Mining and Present Conditionsmentioning

confidence: 99%

“…The ore of these mines, especially that of the Mowry, was said to be of high value, yielding, besides the large percentage of silver, about 50 per cent of lead, which was in demand by the neighboring companies to be used as flux in reducing their less favored ores. The Santa Rita and Patagonia mountains contain a score or more of the crude adobe smelters or 1 Hall, James, Parry, C. C., and Schott, Arthur, Paleontology and geology of the boundary: Kept.. U. S. and Mexican Boundary Survey, by Maj. W. H. Emory,vol. 1,pt.…”

Section: Mstory Of Mining and Present Conditionsmentioning

confidence: 99%

“…A year later the mine was acquired by the present owner, the Ivanhoe Mining Co., of Minneapolis, Minn. 1 The property comprises a group of 22 claims. At the time of visit it had produced and shipped some ore,2 amounting, it is said, to $700 more than the cost of development work-and expenses.…”

Section: An Hoe Minementioning

confidence: 99%

“…1 Developments and equipment. The mine is well developed to a depth of about 500 feet by shafts, tunnels, drifts, inclines, winzes, The niain crosscut, in the bottom of the mine, runs north and is 800 feet long.…”

Section: Projection Of Adit Through Tvru'cfi Most Of the Ore'was Takementioning

confidence: 99%

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Mineral deposits of the Santa Rita and Patagonia Mountains, Arizona

Schrader¹,

Hill²

1915

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Section: Mstory Of Mining and Present Conditionsmentioning

confidence: 99%

Section: Mstory Of Mining and Present Conditionsmentioning

confidence: 99%

Section: Mstory Of Mining and Present Conditionsmentioning

confidence: 99%

Section: An Hoe Minementioning

confidence: 99%

Section: Projection Of Adit Through Tvru'cfi Most Of the Ore'was Takementioning

confidence: 99%

See 3 more Smart Citations

Mineral deposits of the Santa Rita and Patagonia Mountains, Arizona

Schrader¹,

Hill²

1915

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Magmatic-vapor expansion and the formation of high-sulfidation gold deposits: Chemical controls on alteration and mineralization

Henley

Berger

2011

Ore Geology Reviews

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Large bulk-tonnage high-sulfidation gold deposits, such as Yanacocha, Peru, are the surface expression of structurally-controlled lode gold deposits, such as El Indio, Chile. Both formed in active andesite-dacite volcanic terranes. Fluid inclusion, stable isotope and geologic data show that lode deposits formed within 1500 m of the paleo-surface as a consequence of the expansion of low-salinity, low-density magmatic vapor with very limited, if any, groundwater mixing. They are characterized by an initial 'Sulfate' Stage of advanced argillic wallrock alteration ± alunite commonly with intense silicification followed by a 'Sulfide' Stagea succession of discrete sulfide-sulfosalt veins that may be ore grade in gold and silver. Fluid inclusions in quartz formed during wallrock alteration have homogenization temperatures between 100 and over 500°C and preserve a record of a vapor-rich environment. Recent data for El Indio and similar deposits show that at the commencement of the Sulfide Stage, 'condensation' of Cu-As-S sulfosalt melts with trace concentrations of Sb, Te, Bi, Ag and Au occurred at N 600°C following pyrite deposition. Euhedral quartz crystals were simultaneously deposited from the vapor phase during crystallization of the vapor-saturated melt occurs to Fe-tennantite with progressive non-equilibrium fractionation of heavy metals between melt-vapor and solid. Vugs containing a range of sulfides, sulfosalts and gold record the changing composition of the vapor. Published fluid inclusion and mineralogical data are reviewed in the context of geological relationships to establish boundary conditions through which to trace the expansion of magmatic vapor from source to surface and consequent alteration and mineralization. Initially heat loss from the vapor is high resulting in the formation of acid condensate permeating through the wallrock. This Sulfate Stage alteration effectively isolates the expansion of magmatic vapor in subsurface fracture arrays from any external contemporary hydrothermal activity. Subsequent fracturing is localized by the embrittled wallrock to provide highpermeability fracture arrays that constrain vapor expansion with minimization of heat loss. The Sulfide Stage vein sequence is then a consequence of destabilization of metal-vapor species in response to depressurization and decrease in vapor density. The geology, mineralogy, fluid inclusion and stable isotope data and geothermometry for high-sulfidation, bulk-tonnage and lode deposits are quite different from those for epithermal gold-silver deposits such as McLaughlin, California that formed near-surface in groundwater-dominated hydrothermal systems where magmatic fluid has been diluted to less than about 30%. High sulfidation gold deposits are better termed 'Solfataric Gold Deposits' to emphasize this distinction. The magmatic-vapor expansion hypothesis also applies to the phenomenology of acidic geothermal systems in active volcanic systems and equivalent magmatic-vapor discharges on the flanks of submarine volcanoes.

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Pyrite–sulfosalt reactions and semimetal fractionation in the Chinkuashih, Taiwan, copper–gold deposit: a 1 Ma paleo‐fumarole

Henley

Berger

2012

Geofluids

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The mineralized fracture system that underlay paleo‐fumarole field at Chinkuashih, Taiwan has been exposed by copper–gold mining to depths of about 550 m below the paleo‐surface. Its mineralogy and systematic variations in metal and semimetal (Fe, Cu, As, Sb, Bi, Hg, Cd, Sn, Zn, Pb, Se, Te, Au, Ag) concentrations provide insights into the chemical responses of a magmatic‐vapor phase as it expands through fracture arrays to the surface and discharges as fumaroles associated with more extensive solfatara. At Chinkuashih, following initial sealing of the fractures by silica‐alunite alteration, brittle failure reestablished discharge from an underlying reservoir of magmatic vapor. Crystalline pyrite was deposited first in the fractures and was succeeded and replaced by ‘enargite’ (Cu3(As,Sb)S4) as sulfosalt encrustations (‘sublimate’) on fracture surfaces and in extensional cracks. Subsequent recrystallization resulted in complex exsolution intergrowths with antimony fractionation to the evolving crystal–vapor interface. Heavy metal fractionation between sulfosalt and vapor enriched the vapor phase in heavy metals that subsequently precipitated as complex Bi–Hg–Sn sulfosalts in discrete areas (paleo‐fumaroles) close to the paleo‐surface in a manner analogous to modern‐day fumaroles on active volcanoes such as Vulcano, Italy. As in similar paleo‐fumaroles (e.g., El Indio, Chile and Lepanto, Philippines), the most characteristic reaction sequence is the partial replacement of the early pyrite by enargite and Fe‐tennantite. It is proposed that this reaction tracks the decrease in the pressure of the underlying magmatic‐vapor reservoir because of the sustained discharge of vapor to the surface.

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On alunite and diaspore from the Rosita Hills

Cited by 3 publications

References 0 publications

Mineral deposits of the Santa Rita and Patagonia Mountains, Arizona

Mineral deposits of the Santa Rita and Patagonia Mountains, Arizona

Magmatic-vapor expansion and the formation of high-sulfidation gold deposits: Chemical controls on alteration and mineralization

Pyrite–sulfosalt reactions and semimetal fractionation in the Chinkuashih, Taiwan, copper–gold deposit: a 1 Ma paleo‐fumarole

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