porphyry gold systems

Porphyry-Related Low Sulfidation Gold Systems | Southwest ...

1998. "Porphyry-Related Low Sulfidation Gold Systems", Southwest Pacific Rim Gold-Copper Systems: Structure, Alteration, and Mineralization, Greg J. Corbett, Terry M. Leach

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IGNEOUS PETROLOGY OF THE COLOSA GOLD-RICH …

continuum of porphyry systems from Cu-Au, through Au-Cu, to the Au-rich and Cu-poor counterpart (Sillitoe, 1979; Sillitoe, 2000; Seedorff et al., 2005). Porphyry gold systems are not a very common type of gold deposit. Deposits assigned to this group include a few porphyries in the Chilean Maricunga belt

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Gold in porphyry copper deposits: its abundance and fate ...

1. Introduction. 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., 2000).They are commonly surrounded by deposits and country rock containing gold that is thought to have been derived from them (Jones, 1992).Gold can be removed from porphyry copper systems by vapors that separate at high temperatures or by ...

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Gold-rich porphyry systems in the Maricunga Belt, northern ...

Reconstruction of the porphyry systems suggests that gold-bearing quartz stockworks were generated 600 to 1,000 m beneath paleosurfaces.Gold-rich porphyry mineralization in the Maricunga belt is closely comparable to that in the Philippines because of the association with dioritic to quartz dioritic porphyry stocks intruded into andesitic ...

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Epithermal Gold for Explorationists | AIG Journal

Leach, T.M., 1999, Evolution of selected porphyry copper-gold systems in the southwest Pacific region and its relevance to exploration in Pacrim ’99 Proceedings, Bali, Indonesia; The Australasian Institute of Mining and Metallurgy, Melbourne, p.211-225.

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Pebble, Porphyry copper deposit - USGS

Pebble is a giant, classic calc-alkalic porphyry copper-gold-molybdenum deposit. It is composed of the East and West zones which represent two coeval hydrothermal centers within a single system. The West zone extends from surface to ~500-m depth and is centered on four small granodiorite plutons emplaced into flysch, diorite, and granodiorite ...

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Drilling at Bramaderos Main returns strong results of 55 ...

Aug 26, 2019· Drilling at Bramaderos Main returns strong results of 55.8m at 0.74g/t gold and 0.15% copper in outcropping porphyry gold-copper system

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Porphyry Deposits - Earth Science Australia Home Page

Radial fracture zones outside the pyrite halo may contain lead-zinc veins with gold and silver values. THEORY The spectrum of characteristics of a porphyry copper deposit reflects the various influences of four main and many transient stages in the evolution of the porphyry hydrothermal system .

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bullmarketrun.com

understanding Of porphyry copper systems are then briefly reviewed as a prelude to the currently preferred genetic model for gold-rich porphyry deposits. Methods used in ex- ploration and discovery of gold-rich porphyry deposits are then discussed, With special attention paid to the relatively minor role played by descriptive and genetic models ...

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Porphyry-Epithermal Transition: Maricunga Belt, Northern …

Porphyry-Epithermal Transition: Maricunga Belt, Northern Chile ... posit at Refugio and the Cavancha deposit at La Pepa are telescoped systems in which banded quartz veinlets ... quartz veinlets in the Maricunga porphyry gold deposits as in-terbanded translucent, white, gray, and black varieties of

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Sulfidation State of Fluids in Active and Extinct ...

environments and on sulfidation states of sulfide assemblages in calc-alkalic porphyry copper, porphyry-related base-metal veins, and epithermal gold-silver deposits. These data are contrasted with compositions of fluids from active systems by plotting vapor compositions on log f S 2 – 1000/T, R H – 1000/T, R S – 1000/T diagrams, where R ...

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A porphyry Cu-Au model – exploration implications

• Porphyry Cu-Au mineralisation deposited separate phase to Mo mineralisation. Mo appears to be immobile and a good indicator of system margins. • Later Au associated with quartz-carb-base metal veins produced by mixing with bi-carbonate waters • Actinolite is a good indicator to proximity to chalcopyrite mineralisation

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Porphyry - an overview | ScienceDirect Topics

Copper, gold, and molybdenum are among the important minerals extracted from these deposits. For modeling purposes a simplified porphyry model was constructed based on known geologic information (Titley, 1982, and Pierce, 1995). An idealized porphyry copper system is shown in Figure 12.12.

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2.2 Porphyry-epithermal mineral system | Geoscience Australia

In the porphyry-epithermal mineral system, pathways for fluids and their contained metals, ligands and sulfur include faults, stratigraphic aquifers and crystallising intrusive bodies. Crystallising intrusions are particularly important pathways for high-temperature, proximal deposits such as porphyry Cu-Au-Mo deposits and Cu-rich skarns.

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CHARACTERISTICS OF PORPHYRY Au-Cu SYSTEMS IN THE ...

CHARACTERISTICS OF PORPHYRY Au-Cu SYSTEMS IN THE ORDOVICIAN MACQUARIE ARC OF NSW Bruce Mowat, Goldminco, Mitchell Hwy, Orange NSW 2800 Stuart Smith, Oxiana Ltd, 9th Floor, 31 Queen St, Melbourne, Vic 3000 Key Words: copper, gold, porphyry systems, Macquarie Arc, Ordovician ... Porphyry gold-copper mineralisation in the Cadia District, NSW, and ...

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PPT – Porphyry and Epithermal Systems -Science-driven ...

Porphyry and epithermal systems the state of play at end of 1960s (2) Ages of copper and gold belts and provinces poorly defined (isotopic dating in its infancy) Zoning patterns of hydrothermal alteration in porphyry and epithermal deposits poorly appreciated ; Porphyry gold and gold-rich porphyry copper deposits undefined (notwithstanding Panguna)

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Anatomy of Porphyry-Related Mineralised Au-Cu-Ag-Mo …

systems have allowed us to apply time to porphyry systems and better understand their staged evolution as well as the evolved hydrothermal fluids which participate in low sulphidation epithermal vein formation (figure 3). Porphyry Au-Cu-Mo Although porphyry Au-Cu-Mo deposits display considerable variation, some broad generalisations are possible.

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Distribution and composition of gold in porphyry gold ...

Mar 14, 2018· Simon G, Kesler SE, Essene EJ, Chryssoulis SL (2000) Gold in porphyry copper deposits: experimental determination of the distribution of gold in the Cu–Fe–S system at 400°C to 700°C. Econ Geol 95:259–270 CrossRef Google Scholar

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Anhydrite in Porphyry Copper systems...just how good is it?

Likely it is just part of an Iron Oxide porphyry system. When it has gold and Copper it's hard to not call it an IOGC. According to the work below, Mafic rock less than 60% SiO2 can host copper ...

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Porphyry and Epithermal Systems | Geological Processes ...

Porphyry and Epithermal Systems-Science-driven Exploration Successes Richard Sillitoe Porphyry and epithermal deposits. Porphyry copper-molybdenum and copper-gold deposits are centred on shallow-level porphyry intrusions. Grasberg, Indonesia. Epithermal gold and silver deposits are typically hosted by volcanic rocks. Round Mountain, Nevada

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Application of metal zoning to gold exploration in ...

APPLICATION OF METAL ZONING TO GOLD EXPLORATION IN PORPHYRY COPPER SYSTEMS 15 5 Sillitoe, R.H. and Bonham, H.F., 1990, Sediment-hosted gold deposits: Distal products of mag- matic-hydrothermal systems.

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Porphyry Copper-Gold and Epithermal Gold-Silver Systems ...

Sep 10, 2015· Research associate Dr. Crystal LaFlamme and PhD candidate Stefano Caruso were joined by Adjunct Professor and CET board member Dr. Jon Hronsky from Western Mining Services and featured in an ABC news clipping and article entitled: Sulfur could hold key to next generation of mining deposits, research says.

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Porphyry copper deposit - Wikipedia

For copper-molybdenum porphyry deposits, formation is broadly concentrated in three time periods: Palaeocene-Eocene, Eocene-Oligocene, and middle Miocene-Pliocene. For both porphyry and epithermal gold deposits, they are generally from the time period ranging from the middle Miocene to the Recent period., however notable exceptions are known.

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Epithermal Gold Deposits Characteristics

A fascinating group and characteristic of Epithermal gold deposits is that you can virtually see them forming today, simply by visiting hot springs. Like those with Yellowstone in Wyoming or Rotorua in New Zealand. This photo is Pamukkale, low sulfidation hot springs in Turkey, with a beautiful white centre terraces. If you like hot springs, you’ll love epithermal.

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VR Expands Bonita Property and Plans for 2019 Exploration ...

Feb 13, 2019· VR Expands Bonita Property and Plans for 2019 Exploration on the Porphyry Copper-Gold System in Nevada. ... The Bonita porphyry copper system has the potential to host one, or several porphyry ...

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Porphyry Gold Deposits of the Refugio District, Maricunga ...

porphyry gold deposits at Refugio in the Maricunga belt con-tain the lowest known copper:gold ratios of any porphyry-type deposit, and previous studies have established their similari-ties to gold-rich porphyry copper deposits (Vila and Sillitoe, 1991; Vila et al., 1991). One of …

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Porphyry Deposits: The World's Largest Source of Copper ...

Porphyry is a textural term for an igneous rock consisting of large-grained crystals such as feldspar or quartz dispersed in a fine-grained silicate rich, generally aphanitic matrix or groundmass.The larger crystals are called phenocrysts.In its non-geologic, traditional use, the term porphyry refers to the purple-red form of this stone, valued for its appearance.

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(PDF) Distribution of gold in porphyry copper deposits

PDF | Analysis of 55 porphyry copper deposits demonstrates a continuum between porphyry copper-gold deposits emplaced at a median depth of 1 km, with a median size of 160 million metric tons of ...

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Alkaline-Related Gold Systems: An Overview | Seeking Alpha

Jul 15, 2019· Gold to silver ratio is much lower in alkaline porphyry systems than in alkaline epithermal systems. Alteration includes potassium, sodium, propylitic, and magnetite replacement (Fig. 3). Fig. 3.

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GOLIATH CONFIRMS TWO LARGE PORPHYRY SYSTEMS ON …

o Multiple lines of evidence confirm the presence of porphyry systems on Lucky Strike: 1. Prolific coarse gold in placer creeks draining extensive area containing widespread porphyry related polymetallic veins; 2. Soil geochemistry defined a 2000 x 400 metre Au-Cu-Mo-Bi-Sb soil anomaly that

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Epithermal Gold Deposits | Geology for Investors

Epithermal gold deposits are among the richest gold deposits in the world with some bonanza grade ore shoots containing more than 1000 g/t gold, or in other words, a kilogram of gold for every tonne of rock mined. Unfortunately, the tonnage of ore in epithermal veins is typically small compared ...

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What is a Porphyry Copper Deposit?

Porphyry copper deposits are also important sources for other metals, including molybdenum, gold and silver. Minor amounts of rhenium, tellurium, arsenic, zinc and platinum group elements are also present in elevated concentrations within these systems and are recovered at some mining operations.

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Mansur, Porphyry copper prospect - USGS

A review of prospects in the immediate area suggests the present level of erosion has exposed the upper levels of the Mansur porphyry system. The deeper seated magnetic anomaly represents a valid porphyry Cu target at depth. Drill intercepts below soil Cu anomaly area report low grade (0.2% Cu) porphyry-style mineralization. Study area name

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CHARACTERISTICS OF HIGH-SULFIDATION EPITHERMAL …

CHARACTERISTICS OF HIGH-SULFIDATION EPITHERMAL DEPOSITS, AND THEIR RELATION TO MAGMATIC FLUID Antonio Arribas Jr. Mineral Resources Department, Geological Survey of Japan, 1-1-3 Higashi, Tsukuba 305, Japan INTRODUCTION A consequence of the increased exploration for gold deposits during the late 1970s and early

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