Copper porphyry deposits

Intrusive Deposits. Deposits included in the intmsive deposit type are those associated with intmsive or anatectic rocks of different chemical composition, eg, alaskite, granite, monzonite, peralkaline syenite, carbonatite, and pegmatite. Examples include the uranium occurrences in the porphyry copper deposits such as Bingham Canyon and Twin Butte in the United States, the Rossing Deposit in Namibia, and Ilimaussaq deposit in Greenland, Palabora in South Africa, and the deposits in the Bancroft area, Canada (15). 

Lateral zonation from a sericitic envelope to an intermediate argillic envelope is common in the porphyry copper deposits and vein-type deposits in granodioritic rocks... 

Porphyry copper deposits Cu-Mo disseminations in granodioritic porphyritic rocks Utah copper The Ruth, Nevada Climax, USA... 

Intrusive Rossing deposit in Nambia, uranium occurrences in porphyry copper deposits as Bingham Canyon and Twin Buttle in USA, the Palabora in South Africa, deposits in the Bancroft area, Canada. 

Coats, R. 1940. Propylitization and related types of alteration on the Comstock Lode. Economic Geology, 35, 1-16 Creasey, S. C. 1959. Some phase relations in hydrothermally altered rocks of porphyry copper deposits. Economic Geology, 54, 351-373. 

Studies of the host rocks to giant porphyry copper deposits in Central and Northern Chile have shown that there are recognizable changes in the geochemistry of the volcanic rocks prior to mineralizing events (Skewes Stern 1995 Kay et al. 1999 Hollings et al. 2005). These include abrupt increases in the LaA b ratios of volcanic rocks associated with... 

Graybeal, F.T. 1982. Geology of the El Tiro area Silver Bell mining district, Pima County, Arizona. Advances in Geology of the Porphyry Copper Deposits Southwest North America. University of Arizona Press, Tucson, AZ. 

Lopez, J.A. Titley, S.R. 1995. Outcrop and Capping Characteristics of the Supergene Sulfide Enrichment at North Silver Bell, Pima County, Arizona. In Pierce, W. Bolm, J.G. (eds.). Porphyry copper deposits of the American Cordillera Arizona Geological Society Digest, 20, 424-435. 

Titley, S. 1994. Silver Bell Porphyry Copper Deposit, Silver Bell Mountains, Pima County, Arizona. U.S. Geological Survey Circular 1103-B, 77-88. 

Mathur, R. et ai. 2005. Cu isotopic fractionation in the supergene environment with and without bacteria. Geochimica et Cosmochimica Acta, 69(22), 5233-5246. Mathur R., et ai. (in print) Exploration potential of Cu isotope fractionation in Porphyry Copper deposits. Journai of Geochemicai Expioratiom... 

Hartley, A.J. Rice, C.M. 2005. Controls on supergene enrichment of porphyry copper deposits in the Central Andes A review and discussion. Mineralium Deposita, 40, 515-525. 

The lithological and hydrothermal alteration units from the geological map of the area (1 1000 scale) are converted to an appropriate format for information synthesis. By considering the conceptual models for porphyry copper deposits and... 

This group of deposits is closely associated in space and time with magmatic intrusions that were emplaced at relatively shallow depths. They have been developed in hydrothermal systems driven by the cooling of magma (e.g., porphyry-type deposits and skams). From 8D- and 8 0-measurements, it has been concluded that porphyry copper deposits show the clearest affinity of a magmatic water imprint (Taylor 1974) with variable involvement of meteoric water generally at late stages of ore formation. 

Compared to porphyry copper deposits 5 " S-valnes in epithermal deposits are more variable due to lower temperatures of formation and significant amounts of both sulfide and sulfate in the hydrothermal flnid. 

FOURNIER (R.O.), 1965. Montmorillonite pseudomorphic after plagioclase in a porphyry copper deposit. Amer. Min. 50, 771-7. 

FOURNIER (R.O.), 1967. The porphyry copper deposit exposed in the liberty open-pit mine near Ely, Nevada. Part II. The formation of hydro-thermal alteration zones. Econ. Geol. 62, 207-27. 

ROSE (A.W.), 1970. Zonal relations of wallrock alteration and sulfide distribution at Porphyry Copper Deposits. Econ. Geol. 65, 920-36. 

Sheppard SMF, Nielsen RL, Taylor HP Jr (1969) Oxygen and hydrogen isotope ratios of clay minerals from porphyry copper deposits. Econ Geol 64 755-777... 

Andersen, K.L. (1978) Reflectance spectroscopy as a remote sensing technique for the identification of porphyry copper deposits. Ph.D. Thesis, MIT. 

Sillitoe, R. H. (1972) A plate tectonic model for the origin of porphyry copper deposits. Econ. Geol., 67,184-97. 

In the case of lead arsenate (acid form), calcium arsenate, and sodium arsenate, the Pb-isotopic compositions closely match those of sulfides from porphyry copper deposits from southeastern Arizona, specifically from the Pima and Silver Bell districts (Bouse et al., 1999). Notably, other major historical producers of arsenic trioxide (e.g., Anaconda Copper Co., US Smelting Co., Jardine Mining Co.) used... 

Bouse, R. M., Ruiz, J., Tidey, S. R., Tosdal, R. M., and Wooden, J. L. (1999). Lead isotope compositions of Late Cretaceous and Early Tertiary igneous rocks and sulfide minerals in Arizona Implications for the sources of plutons and metals in porphyry copper deposits. Econ. Geol. 94, 211-224. 

Bodnar, R. J. (1995). Fluid inclusion evidence for magmatic source of metals in porphyry copper deposits. Miner. Assoc. Canada, Short Course Series 23, 139—152. 

Simon G., Kesler S. E., Essene E. J., and Chryssouhs S. L. (2000) Gold in porphyry copper deposits experimental determination of the distribution of gold in the Cu-Ee-S system at 400-700°C. Econ. Geol. 95. 

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