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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.

Gold in porphyry copper deposits: its abundance and fate

Oct 01, 2002 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

Metallis Resources, Inc. Cole Porphyry System

Several 2m intervals of continuous trench samples assayed anomalous gold ranging from 0.5 g/t to 1.25 g/t Au in the Cole porphyry system. The 2019 program was designed to test the continuity of epithermal high-grade gold and porphyry copper-gold mineralization at the Cole Target.

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

Porphyry an overview ScienceDirect Topics

Porphyry deposits are large, low- to medium-grade deposits in which primary (hypogene) ore minerals are dominantly structurally controlled and are spatially and genetically related to felsic to intermediate porphyritic intrusions (Kirkham, 1971, 1972).The main metals in a porphyry are Cu, Mo, and smaller amounts of gold, although Sn, W, and Ag can be found in some porphyry deposits (Kirkham

Godolphin discovers gold-copper porphyry system in Lachlan

Godolphin Resources says it has discovered a new copper-gold porphyry-style mineralised system at its Copper Hill East project 35km north of Orange, NSW, in the revered Lachlan Fold Belt following an initial round of deep RC drilling. The most notable intercept from the recent RC holes was 32m at 0.29 g/t gold and 0.13 per cent copper from 210m including 12m going 0.45 g/t

2.2 Porphyry-epithermal mineral system Geoscience Australia

Although, geologically recent porphyry-epithermal mineral systems are mostly thought to form in magmatic arcs (both continental and oceanic) associated with convergent plate margins (Seedorff et al., 2005; Simmons et al., 2005), the geological setting of older examples is less clear, and some workers have suggested alternative settings that do

Descriptive model of Porphyry Au USGS

ORE CONTROLS/EXPLORATION GUIDES: Zoning of near surface hot-spring Hg-S deposits to zones of vuggy silica and advanced argillic alteration at depth hosting gold and/or silver quartz-chalcedony veins may indicate presence of porphyry gold system at depth of 0.5-1.0 km below paleosurface. Zoning may have a lateral component of 1-3 km. Ore bodies

Why a former Rio Tinto executive is backing Gold Mountain

Nov 29, 2020 Large copper–gold porphyry systems have often been referred to as ‘elephants’. This is based on the massive size of these ore bodies, and also takes into account that the Papuan Mobile Belt, where Gold Mountain is exploring, is no stranger to elephants including world-class mines such as Grassberg, Ok Tedi and Panguna.

PORPHYRY DEPOSITS Earth Science

The major products from porphyry copper deposits are copper and molybdenum or copper and gold. The term porphyry copper now includes engineering as well as geological considerations; It refers to large, relatively low grade, epigenetic, intrusion-related

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

Descriptive model of Porphyry Au USGS

ORE CONTROLS/EXPLORATION GUIDES: Zoning of near surface hot-spring Hg-S deposits to zones of vuggy silica and advanced argillic alteration at depth hosting gold and/or silver quartz-chalcedony veins may indicate presence of porphyry gold system at depth of 0.5-1.0 km below paleosurface. Zoning may have a lateral component of 1-3 km. Ore bodies

IGNEOUS PETROLOGY OF THE COLOSA GOLD-RICH

Gold, 2009). The Colosa porphyry has inferred resources of 468.8 Mt at 0.86 g/t (AngloGold Ashanti, 2008) which makes it the porphyry gold system with the biggest tonnage of material and contained Au discovered to date (Fig. 2). Regional Geologic Setting The Central Cordillera of Colombia has a complex history of collision, accretion, faulting,

Godolphin discovers gold-copper porphyry system in Lachlan

Godolphin Resources says it has discovered a new copper-gold porphyry-style mineralised system at its Copper Hill East project 35km north of Orange, NSW, in the revered Lachlan Fold Belt following an initial round of deep RC drilling. The most notable intercept from the recent RC holes was 32m at 0.29 g/t gold and 0.13 per cent copper from 210m including 12m going 0.45 g/t

Godolphin discovers gold-copper porphyry system in Lachlan

ASX-listed junior explorer, Godolphin Resources, says it has discovered a new copper-gold porphyry-style mineralised system at its Copper Hill East project 35km north of Orange, NSW, in the revered Lachlan Fold Belt following an initial round of deep RC drilling.

Why a former Rio Tinto executive is backing Gold Mountain

Nov 29, 2020 Large copper–gold porphyry systems have often been referred to as ‘elephants’. This is based on the massive size of these ore bodies, and also takes into account that the Papuan Mobile Belt, where Gold Mountain is exploring, is no stranger to elephants including world-class mines such as Grassberg, Ok Tedi and Panguna.

Gold Mountain PNG porphyry mineralisation identified

Recent times have seen a number of porphyry copper-gold gold discoveries by junior to mid-tier explorers, with the most advanced being Xanadu (ASX: XAM, TSX: XAM) with their Kharmagtai and associated discoveries in Mongolia, and Solgold (LSE: SOLG, TSX: SOLG) with the Cascabel Project in Ecuador. In addition, Sunstone Metals...

Intrusion-related Gold Systems. A brief summary by Bruce

progression of classification of gold deposits related to magmatic rocks as commencing with the term porphyry gold deposits (after the usage of porphyry copper deposits) in 1992 by Hollister. This ignores the fact that Sillitoe (1979) had earlier introduced the concept of a porphyry gold deposit style.

IGNEOUS PETROLOGY OF THE COLOSA GOLD-RICH

Gold, 2009). The Colosa porphyry has inferred resources of 468.8 Mt at 0.86 g/t (AngloGold Ashanti, 2008) which makes it the porphyry gold system with the biggest tonnage of material and contained Au discovered to date (Fig. 2). Regional Geologic Setting The Central Cordillera of Colombia has a complex history of collision, accretion, faulting,

Meteoric Resources detects ‘giant’ potential porphyry

Dec 08, 2020 The province has been the focus of artisanal mining and gold exploration for more than 30 years but has more recently emerged as a region for porphyry copper-molybdenite-gold, gold-copper, and gold-polymetallic after the discovery of several porphyry-like magmatic-hydrothermal systems.

Intrusion-related Gold Systems. A brief summary by Bruce

progression of classification of gold deposits related to magmatic rocks as commencing with the term porphyry gold deposits (after the usage of porphyry copper deposits) in 1992 by Hollister. This ignores the fact that Sillitoe (1979) had earlier introduced the concept of a porphyry gold deposit style.

Godolphin discovers gold-copper porphyry system in Lachlan

ASX-listed junior explorer, Godolphin Resources, says it has discovered a new copper-gold porphyry-style mineralised system at its Copper Hill East project 35km north of Orange, NSW, in the revered Lachlan Fold Belt following an initial round of deep RC drilling.

[PDF] Porphyry Gold Deposits of the Refugio District

The porphyry gold deposits of the Refugio district and similar deposits in the Maricunga belt contain the lowest known copper to gold ratios (% Cu/ppm Au = ~0.03) of any porphyry-type deposit. The gold deposits are associated with subvolcanic andesitic to dacitic intrusions emplaced into coeval volcanic rocks. Both the Verde and Pancho deposits are zoned in space from a deeper zone of banded

Belgravia Porphyry Project — Krakatoa Resources

Porphyry copper-gold systems akin to the Cadia Valley porphyry cluster and Alkane’s Northern Molong Porphyry Project. High-grade gold skarn mineralisation

Gold Mountain PNG porphyry mineralisation identified

Recent times have seen a number of porphyry copper-gold gold discoveries by junior to mid-tier explorers, with the most advanced being Xanadu (ASX: XAM, TSX: XAM) with their Kharmagtai and associated discoveries in Mongolia, and Solgold (LSE: SOLG, TSX: SOLG) with the Cascabel Project in Ecuador. In addition, Sunstone Metals...

Epithermal Gold Deposits Geology for Investors

Nov 21, 2019 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 with other types of lower grade gold deposits. Gold mineralisation within epithermal veins

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.

Porphyry Copper Systems* GeoScienceWorld

Porphyry Cu systems host some of the most widely distributed mineralization types at convergent plate boundaries, including porphyry deposits centered on intrusions; skarn, carbonate-replacement, and sediment-hosted Au deposits in increasingly peripheral locations; and superjacent high- and intermediate-sulfidation epithermal deposits.

Porphyry (geology) Wikipedia

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.

Porphyry and Epithermal Systems Geological Processes

16 Moz gold and >600 Moz silver. 10 Tops of porphyry copper deposits. Guinaoang porphyry copper-gold system, Philippines Discovered 1983, RGC Exploration >500 Mt @ 0.4% Cu, 0.4 g/t Au. Deposit concealed beneath advanced argillic lithocap containing highsulphidation mineralization. 11 Tops of low- and intermediate-sulphidation

Godolphin delves deeper into Lachlan discovery Business News

Dec 07, 2020 ASX-listed explorer, Godolphin Resources, has encountered further hints of a gold-copper porphyry-style mineralised system at its Turrawonga discovery within the company’s Copper Hill East project 35km north of Orange in NSW’s Lachlan Fold Belt. It recently completed a couple of new deep infill drill holes at Turrawonga after an initial two holes returned 32m at 0.29 g/t gold

Models and Exploration Methods for Major Gold Deposit Types

known porphyry and high-sulfidation epithermal gold deposit types, as well as skarn and manto type deposits, formed in continental and oceanic convergent plate settings. These deposits are best regarded as components of large hydrothermal systems centered on high-level, generally oxidized, intermediate to felsic porphyry stocks (Figure 1; Table 1).