Magnetite chemistry in the porphyry copper systems of. Also evaluating the importance of regionalscale structures, sillitoe 1993 con. Characteristics and controls of the largest porphyry. Sillitoe s 2010 porphyry copper systems paper describes carbonate replacement deposits as either chimney or manto, suggesting that the term manto has more to do with the geometry of the orebody rather than a specific genetic deposit style. The present work attempts to characterize magnetite chemistry in some collisional chahfiruzeh and keder. In contrast, a number of detailed studies combining microtextural.
Sillitoe and perello 2005 of intrusive rocks, major and byproduct metals, and other. These can also contain skarn, carbonatereplacement, sedimenthosted, and high and intermediate sulphidation epithermal deposits and precious metal mineralisation sillitoe, 2010. Epithermal deposits are genetically associated with porphyry cu. Figure 6 from porphyry copper systems semantic scholar. Porphyry copper molybdenum and copper gold deposits are centred on shallowlevel porphyry intrusions. Porphyry copper deposit model, chapter b of mineral deposit. We discuss the geology of provinces that contain giant deposits, magma compositions, metal grades, and the tectonic environments of ore formation for some of the youngest porphyry copper gold and copper molybdenum systems. Porphyry cu systems are defined as large volumes 10. Preliminary model of porphyry copper deposits usgs. The age and distribution of deposits exposed at the surface suggest that mountain exhumation is. Copper skarn deposits occur near many porphyry copper host intru sions that intruded carbonatebearing units einaudi and others, 1981, and skarn mineral zoning patterns may be useful in the targeting of a potentially associated porphyry copper deposit. Deposits assigned to this group include a few porphyries in the chilean maricunga belt. Porphyry gold systems are not a very common type of gold deposit. Characteristics, continua, and causes marco einaudi.
View test prep 2010 porphyry sillitoe from geology 1 at university of texas. Largescale sodiccalcic alteration around porphyry copper. Porphyry ore systems can be defined as large volumes of hydrothermally altered rock centred on a porphyry stock intrusion sillitoe, 2010. They are commonly surrounded by deposits and country rock containing gold that is thought to have been derived from them jones, 1992. Epma results for magnetite samples show collisional deposits have higher average contents of fe and ca compared to those of precollisional systems. Geological criteria for porphyry copper exploration. I suggest that this article be merged with skarn deposits as a subtopic. Porphyry and epithermal systems geological processes. Porphyry and epithermal systems sciencedriven exploration successes richard sillitoe porphyry and epithermal deposits.
A climate signal in exhumation patterns revealed by. Porphyry cu systems host some of the most widely distributed mineralization types at convergent plate boundaries, including porphyry deposits. Porphyry copper deposits of the american cordillera. Request pdf porphyry copper systems porphyry cu systems host some of.
The alteration and mineralization in porphyry cu systems, occupying many cubic. Porphyry cu systems are defined as large volumes 10100 km3 of. Rye, 1993, and recent studies of the lepanto highsulfidation gold copper and adjacent far southeast porphyry copper gold deposits arribas et al. Here, the life span of the major quellaveco porphyry copper molybdenum deposit in southern peru, including the approximate duration of copper introduction, is determined by using exclusively upb zircon dating. Geological crit eria for porphyry copper exploration. Geology and genesis of major copper deposits and districts of the world.
Giant porphyryrelated metal camps of the worlda databas. Tectonic control, reconstruction and preservation of the. These are large scale magmatichydrothermal systems associated with a series of porphyritic intrusions, which result in extensive alteration footprints that we map and model to target high grade copper gold mineralization. General setting of porphyry copper and associated deposit types modified from sillitoe and bonham, 1990. Porphyry copper depositsthe primary source of the worlds copper are a consequence of the degassing of intrusion complexes in magmatic arcs associated with ancient subduction zones1,2. Transitions between porphyry copper deposits and highsulfidation epithermal gold deposits also have been proposed sillitoe, 1973, 1983, 1988, 1989. A porphyry stock is formed by the intrusion of oxidised magma. Porphyry related metal deposits are largetonnage, generally lowgrade, hydrothermal deposits related to igneous intrusions emplaced at high crustal levels that include many of the worlds largest accumulations of cu, mo, au, ag, sn, and w. Copper gold porphyry occurrences goldonly occurrences volta resources, now b2gold 22 mt at 0. Quaternary andesiticdacitic volcanoes that could be the surface expressions of porphyry cu systems are mostly too shallowly eroded to reveal underlying deposits should. Lesage, mineral deposit research unit, the university of british columbia, vancouver, bc. Pdf porphyry copper systems daniela olivares sedan. Copper is a moderately incompatible chalcophile element. Please click on the service to which you have a subscription to obtain access.
Sillitoe 1993, while porphyry mo deposits are associated within more siliceous quartz monzonite and alkali granite intrusions white et al. The crust thickening and terranes collision in the bangongnujiang suture zone, combining with. Field based vectors used to explore for porphyry cuau deposits. Copper skarn deposits occur near many porphyry copper host intru sions that intruded carbonatebearing units einaudi and others, 1981, and skarn mineral zoning patterns may be useful in the targeting of a potentially associated porphyry copper deposit meinert and others, 2005. Average gold contents are generally gt, although a few deposits are richer fig. Generalized porphyry copper model anatomy and alteration zoning anatomy of calcalkalic porphyry copper and related mineralization alteration zonation patterns in calcalkalic porphyry systems modified from. Therefore, porphyry cu deposits are usually oxidized with oxygen fugacities. The wafigolpu porphyry cuau system is bounded by a ne to nne trending fault zone known as the wafi transfer, and intrudes a basement sequence of weakly metamorphosed wellbedded siltstones and conglomerates of the oligocene langimar formation. Porphyry cu mo au deposits are commonly associated with shallowly emplaced, relatively lowto hightemperature 300700 c hydrothermal systems richards, 2011richards, 20sillitoe, 2010. Porphyry copper systems 39 0361 012898000000 00 600 39 2000 gold rich porphyry from geology 1 at university of texas. Mapping hydrothermal zoning pattern of porphyry cu.
Examples from the highland valley copper district, guichon batholith, southcentral british columbia k. Porphyry cu systems host some of the most widely distributed mineralization types at convergent plate boundaries, including porphyry deposits centered on intrusions. Porphyry copper deposits are emplaced at a fixed crustal depth in convergent tectonic settings. See sillitoe, 2010, porphyry systems economicgeology. Porphyry copper deposits contain up to 100 t of gold and are among the largest reservoirs of gold in the upper crust kerrich et al. It is acquisition of this geologic detail matichydrothermal activity at the cerro. Porphyry copper gold deposits form in a variety of volcanic environments, most commonly in continental margins and intraoceanic arcs. Many visually and topographically prominent and, commonly, areally extensive advanced argillic alteration richard h. This database tabulates basic information about the worlds largest porphyhryrelated deposits in order to help define their size. If you dont have a subscription, clicking will allow you to obtain payperview access.
Cu concentrations in these cupolas can reach up to wt. The sequence of alterationmineralization events charted above is principally a consequence of progressive rock and fluid cooling, from 700 to porphyry deposits centered on intrusions. Porphyry copper deposits of the american cordillera frances wahl pierce and john g. Codes the australian research councils centre for excellence in ore deposit research, university of tasmania, private bag 126, hobart, tasmania 7001, australia. Why no porphyry copper deposits in japan and south korea. The speciation of sulfur is controlled by oxygen fugacity.
Ali javad porphyry cuau deposit is located 20 km north of ahar city in arasbaran metallogenic zone which is considered as a part of alphimalayan mineralization belt. Pdf porphyry copper systems introduction miguel peral. Sillitoe london, uk abstract this analysis concludes that there is little realistic likelihood of discovering large, highgrade porphyry cu deposits in japan and south korea because of an unusual combination of geological factors. Cenozoic tectonics and porphyry copper systems of the. Eoceneoligocene porphyry copper systems hosted in the kerman cenozoic magmatic arc kcma. Extraction of spectral information from landsat tm data and merger with. Committee for coordination of joint prospecting for mineral resources in asian offshore areas ccop, ccop technical publication 14, 89 p. The sombrero butte breccia pipe system is located at the southern end of the copper creek bunker hill mining district in the laramide porphyry copper province of southwestern north america titley, 1982. Largescale sodiccalcic alteration around porphyry copper systems. This increase began in the early 1960s, and the numbers of publications reached a peak during. Porphyry cu systems are initiated by injection of oxidized magma saturated with s and metalrich, aqueous fluids from cupolas on the tops of the subjacent parental plutons. Porphyry cu systems host some of the most widely distributed mineralization types at convergent plate boundaries.
The gold byproduct of porphyry cu deposits, as well as gold in epithermal deposits high and intermediate sulfidation in these intrusioncentered systems see sillitoe, 2010, porphyry systems accounts for about 40% of non placer gold production. The understanding of porphyry systems depends critically on determination of the. Predating or associated with those fluids are vertical dikes of porphyritic intrusive rocks from which this deposit type derives its name. Like most ore deposits, porphyry copper deposits pcds are. Anatomy of porphyryrelated mineralised aucuagmo systems.
Gold can be removed from porphyry copper systems by vapors that separate at high. Anatomy of porphyry related aucuagmo mineralised systems. Sillitoe, 27 west hill park, highgate village, london n6 6nd, uk. Porphyry copper deposits are copper orebodies that are formed from hydrothermal fluids that originate from a voluminous magma chamber several kilometers below the deposit itself. Epithermal gold and silver deposits are typically hosted by volcanic rocks. Duration of magmatichydrothermal systems that form porphyry copper deposits 18. Porphyry deposits are the worlds principal resources of cu, mo, and re, and are major. Generalized models of porphyry copper deposits anatomy. Application of nearinfrared spectroscopy to sensor based.