The porphyry copper deposit at El Salvador, Chile

Gustafson, Lewis B.; Hunt, John Paul

doi:10.2113/gsecongeo.70.5.857

Cited by 779 publications

(458 citation statements)

References 0 publications

Supporting

Mentioning

401

Contrasting

Unclassified

Order By: Relevance

“…The relationship between porphyry-style (K-silicatestable) mineralization and massive enargite-pyrite deposits is less certain, but evidence from Lepanto (Sillitoe, 1983(Sillitoe, , 1990) and other deposits (R.H. Sillitoe, written commun., 1992) indicates that enargite-pyrite postdates porphyry-style stockwork mineralization. This is in accord with well-documented temporal relations at El Salvador (Gustafson and Hunt, 1975), where advanced argillic assemblages are superimposed on previously formed potassic alteration. The existence of an advanced argillic-enargite-pyrite association, manifested either as massive enargite-pyrite deposits or as an early copper-rich stage in gold veins, seems to be a prerequisite for formation of high-grade quartz-alunite-gold deposits, possibly because well-developed structures are necessary for both deposit types.…”

Section: Relationship Between Porphyry Copper Enargite-pyrite and Qusupporting

confidence: 88%

“…Gold and copper occur together in a suite of genetically related deposit types that includes porphyry copper-gold Lowell and Guilbert (1970), Gustafson andHunt (1975), SiUitoe (1973). deposits, and massive enargite-pyrite veins and replacements, in addition to the high-grade enargite-or tennantitebearing quartz-alunite-gold veins described above (Sillitoe, 1988(Sillitoe, , 1989. In porphyry deposits there is a well-documented spatial pattern of alteration and ore and gangue minerals ( fig.…”

Section: Intrusion-related Copper-gold Deposits General Characteristicsmentioning

confidence: 99%

“…1, table 2), in which deeper and more central zones have assemblages indicative of neutral to alkaline fluids with low f §2 and relatively high f^ (Rose and Burt, 1979;Beane and Titley, 1981). Peripheral to many porphyry deposits, and particularly at high levels, alteration and ore-mineral assemblages indicate that mineralizing fluids had higher H+ activities and f §2 (Gustafson and Hunt, 1975;Meyer and Hemley, 1967). These conditions are indicated by phyllic, argillic, and advanced argillic zones (Meyer and Hemley, 1967).…”

Section: Intrusion-related Copper-gold Deposits General Characteristicsmentioning

confidence: 99%

“…Geological Survey Mission, Unit 62101, APO AE 09811-2101. from a variety of different types of ore deposits (Gustafson and Hunt, 1975;Bartos, 1989;Large and others, 1989). The formation of alteration and vein assemblages indicative of fluids with low pH and elevated fO2 and (or) fS2 is a common feature in a variety of precious-and base-metal ores.…”

Section: Introductionmentioning

confidence: 99%

“…These include deposits considered to be epithermal (Ashley, 1990;John and others, 1989) as well as those inferred to have formed at relatively high temperatures (Sillitoe, 1983;Brimhall, 1980). In many cases, alteration by acid fluids occurs late in the history of hydrothermal activity (Gustafson and Hunt, 1975), whereas, in others, acid and oxidized fluids have been succeeded by those with higher pH and lower oxidation state (Beane and others, 1991). The origin of these acid fluids is a matter of debate, with a strong component of direct magmatic addition likely in at least some deposits.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Advances in research on mineral resources, 1994

Berger¹

1994

View full text Add to dashboard Cite

Cover. Part of a color shaded-relief aeromagnetic map of north-central Minnesota. Color changes represent broad changes in magnetic field strength. The warm colors (red, orange, and yellow) represent areas of magnetic field highs; the cool colors (green, blue, and purple) represent magnetic field lows.[From Horton, R.J., Day, W.C., and Bracken, R.E., Aeromagnetic survey of north-central Minnesota, chap. T of Scott, R.W., Jr., Detra, P.S., and Berger, B.R., eds., Advances Related Geographic landscapes change only slowly, but political and economic landscapes can change abruptly and unexpectedly The geological sciences are contributors to changes in these landscapes, but they also serve as a source of information on which an informed polity may base decisions on behalf of a society. The U.S. Geological Survey (USGS) is dedicated to providing information for the public good in all aspects of the geological sciences, including mineral resources.Mineral resources are a part of the geosciences that impact all aspects of a society from national economic security to national defense to land-use decisions to health and welfare these impacts affect not just humans but all other animals as well as all flora. Minerals are an essential part of the well-being of both a society and the Earth. They serve as the basis for infrastructure, technological innovation and development, economic policies, national defense, and national economic security; they are also essential to informed decisions on environmental risk and environmental tradeoffs in any decision-making process.The USGS provides mineral resource information, knowledge, and technical analyses from highly trained scientists with broad-ranging technical skills to Federal, State, and local governments; industries; schools and universities; and the general public of the United States. It also engages in cooperative studies with other countries and their institutions to provide training, exchange information and understanding, and attack important scientific problems. This Bulletin, Advances in research on mineral resources, 1994, reports progress on some of the current domestic and international research activities of the Office of Mineral Resources, Geologic Division of the USGS. ESTABLISHING A GEOLOGIC FRAMEWORK FOR MINERAL DEPOSITSSince the emergence of economic geology as a recognized subdiscipline within the earth-science research community within the last century, there has been heated debate about the role of igneous processes in the genesis of deposits that are spatially associated with intrusions and volcanic rocks. Do the metals in most deposits come from magmas, or is the magma merely a partial contributor or simply a heat engine? Even the use of sophisticated new technologies in the post-World War II era has not caused the issue to wither. Although there are stable-isotope methodologies to fingerprint probable water sources and radiogenic methodologies that reveal the source of some metals (and most deposits and rocks can now be dated with high precision), the...

show abstract

Section: Relationship Between Porphyry Copper Enargite-pyrite and Qusupporting

confidence: 88%

Section: Intrusion-related Copper-gold Deposits General Characteristicsmentioning

confidence: 99%

Section: Intrusion-related Copper-gold Deposits General Characteristicsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Advances in research on mineral resources, 1994

Berger¹

1994

View full text Add to dashboard Cite

show abstract

Understanding Copper Isotope Behavior in the High Temperature Magmatic‐Hydrothermal Porphyry Environment

Gregory

Mathur

2017

Geochem Geophys Geosyst

View full text Add to dashboard Cite

Copper stable isotope geochemistry has the potential to constrain aspects of ore deposit formation once variations in the isotopic data can be related to the physiochemical conditions during metal deposition. This study presents Cu isotope ratios for samples from the Pebble porphyry Cu‐Au‐Mo deposit in Alaska. The δ65Cu values for hypogene copper sulfides range from −2.09‰ to 1.11‰ and show linear correlations with the δ18O isotope ratios calculated for the fluid in equilibrium with the hydrothermal alteration minerals in each sample. Samples with sodic‐potassic, potassic, and illite alteration display a negative linear correlation between the Cu and O isotope results. This suggests that fractionation of Cu isotopes between the fluid and precipitating chalcopyrite is positive as the hydrothermal fluid is evolving from magmatic to mixed magmatic‐meteoric compositions. Samples with advanced argillic alteration display a weak positive linear correlation between Cu and O isotope results consistent with small negative fluid‐chalcopyrite Cu isotope fractionation during fluid evolution. The hydrothermal fluids that formed sodic‐potassic, potassic, and illite alteration likely transported Cu as CuHS0. Hydrothermal fluids that resulted in advanced argillic alteration likely transport Cu as CuCl2−. The pH conditions also control Cu isotope fractionation, consistent with previous experimental work. Larger fractionation factors were found between fluids and chalcopyrite precipitating under neutral conditions contrasting with small fractionation factors calculated between fluids and chalcopyrite precipitating under acidic conditions. Therefore, this study proposes that hydrothermal fluid compositions and pH conditions are related to Cu isotope variations in high temperature magmatic‐hydrothermal deposits.

show abstract

The dynamic interplay between saline fluid flow and rock permeability in magmatic–hydrothermal systems

Weis

2012

Crustal Permeability

View full text Add to dashboard Cite

Magmatic-hydrothermal ore deposits document the interplay between saline fluid flow and rock permeability. Numerical simulations of multiphase flow of variably miscible, compressible H20-NaCI fluids in concert with a dynamic permeability model can reproduce characteristics of porphyry copper and epithermal gold systems. This dynamic permeability model uses values between 10 -22 and 10 -13 m 2 , incorporating depth-dependent permeability profiles characteristic for tectonically active crust as well as pressure-and temperature-dependent relationships describing hydraulic fracturing and the transition from brittle to ductile rock behavior. In response to focused expulsion of magmatic fluids from a crystallizing upper crustal magma chamber, the hydrothermal system self-organizes into a hydrological divide, separating an inner part dominated by ascending magmatic fluids under nearlithostatic pressures from a surrounding outer part dominated by convection of colder meteoric fluids under near-hydrostatic pressures. This hydrological divide also provides a mechanism to transport magmatic salt through the crust. With a volcano at the surface above the hydrothermal system, topography-driven flow reverses the direction of the meteoric convection as compared to a flat surface, leading to discharge at distances of up to 7 km from the volcanic center. The same physical processes at similar permeability ranges, crustal depths, and flow rates are relevant for a number of active systems, including geothermal resources and excess degassing at volcanos. The simulations further suggest that the described mechanism can separate the base of free convection in high-enthalpy geothermal systems from the magma chamber as a driving heat source by several kilometers in the 2 vertical direction in tectonic settings with hydrous magmatism. These root zones of high-enthalpy systems may serve as so-called super-critical geothermal resources. This hydrology would be in contrast to settings with anhydrous magmatism, where the base of the geothermal systems may be closer to the magma chamber.

show abstract

The porphyry copper deposit at El Salvador, Chile

Cited by 779 publications

References 0 publications

Advances in research on mineral resources, 1994

Advances in research on mineral resources, 1994

Understanding Copper Isotope Behavior in the High Temperature Magmatic‐Hydrothermal Porphyry Environment

The dynamic interplay between saline fluid flow and rock permeability in magmatic–hydrothermal systems

Contact Info

Product

Resources

About