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Greenschist Gold Ore, Ontario, Canada. Thin Section ...

This is a thin section of a rock from a gold mining site at Kirkland Lake, Ontario, Canada. From the Achean shield greenschists, this rock contains mainly actinolite, bright green in hand sample, showing fine twinning and some dissolution texture, also muscovite and, I think crystalline sillimanite (or could be anthophyllite). Unfortunatly no gold.

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2.7 Orogenic mineral system Geoscience Australia

2021-6-3  Greenschist-facies lode gold deposits typically have a proximal sericite-dominated alteration zone, surrounded by carbonate-rich zones (Eilu and Groves, 2001). Sulfide minerals in the ores typically include pyrite and may include arseonpyrite and

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SYN-METAMORPHIC GOLD DEPOSITS IN AMPHIBOLITE

2016-9-19  Ores from gold deposits in high-temperature terrains in the Yilgarn Block have geochemical com-positions generally indistinguishable from those in greenschist-facies terrains. However, typicalCO2contents of ores in maÞc-hosted deposits in lower-amphibolite facies terrains are 3 Ð 6 wt.%and in higher grade terrains 1 Ð 2 wt.%, hence signiÞcantly lower than the range of 5 Ð 20 wt.%in greenschist-facies

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Orogenic Gold Deposits: Genesis and Exploration

gold intrusions generally occur at, or within a few kilometers of the deposits. Greenschist to lower amphibolite metamorphic conditions, having been reached within a few tens of million years prior to ore formation, represent peak P-T conditions in the wallrocks for most deposits. However, orogenic gold deposits in eastern

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Greenstone Schist/Greenschist - Gold Nugget Hunting ...

2012-5-4  Greenstone or Greenschist is a metamorphic or mafic volcanic rock, they are rocks that have been changed in the rock cycle due to heat. and pressure into a new form of rock and are one of the major rock types to hold gold and other matalic minerals.

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Main types of gold ore forming systems and their ...

2014-5-1  Regardless of the age and formation features, manifestations of proper gold ore formations are controlled by a common factor, the degree of metamorphism of host rocks - not above the sericite-biotite subfacies of the greenschist facies, and belong to the group of hydrothermal-metasomatic ore forming systems conditioned by alkali-acid differentiation of matter in temperature gradient field with ore

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shear zone comparison - Monash University

2005-12-13  fashion. Greenschist facies gold deposits in the Norseman-Wiluna Belt provide numerous examples of this contrast, where granite dykes or dolerite sills are intensely fractured while surrounding talc-schist is strongly sheared. It is in fact this contrast in behaviour and strength at greenschist

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Geochemistry, alteration, and genesis of gold ...

2004-12-3  1996). The gold mineralization of the Adola Belt occurred over a prolonged deformation history, but closely related to alteration, retrograde greenschist facies assemblage, and brittle-ductile deformation of late D 2 and D 3 transpressional shear zones (Worku, 1996). The gold mineralizations in the Adola Belt, similar to

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Shear-zone-related gold mineralization in quartz

2020-12-1  This world-class orogenic gold deposit is part of the Rio das Velhas greenstone belt, a typical association of mafic volcanic rocks, banded iron formation (BIF), carbonaceous and micaceous phyllites, metamorphosed to the greenschist facies conditions.

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Devolatilization of metabasic rocks during greenschist ...

2006-7-4  Rocks with greater initial proportions of carbonate minerals experience a second fluid production event at temperatures above the greenschist to amphibolite facies transition, producing a more CO 2 ‐rich fluid (X CO2 = 0.2–0.3). Rocks may achieve these higher proportions of carbonate minerals either via more extensive seafloor alteration or via infiltration of fluids.

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Greenschist Gold Ore, Ontario, Canada. Thin Section ...

This is a thin section of a rock from a gold mining site at Kirkland Lake, Ontario, Canada. From the Achean shield greenschists, this rock contains mainly actinolite, bright green in hand sample, showing fine twinning and some dissolution texture, also muscovite and,

More

Greenstone Schist/Greenschist - Gold Nugget Hunting ...

2012-5-4  Greenstone or Greenschist is a metamorphic or mafic volcanic rock, they are rocks that have been changed in the rock cycle due to heat. and pressure into a new form of rock and are one of the major rock types to hold gold and other matalic minerals.

More

GREENSTONE/CHLORITE-SCHIST/GREENSCHIST

2012-3-21  Greenstone belts often contain important ore deposits of gold, silver, copper ore, zinc and lead. Well known examples of economically valuable greenstone belts have been mined in Canada, Australia, Africa and Brazil- and to a lesser extent in the United States.

More

Orogenic Gold Deposits: Genesis and Exploration

gold intrusions generally occur at, or within a few kilometers of the deposits. Greenschist to lower amphibolite metamorphic conditions, having been reached within a few tens of million years prior to ore formation, represent peak P-T conditions in the wallrocks for most deposits. However, orogenic gold deposits in eastern

More

greenschist Geology for Investors

2014-11-5  Make sense of mining company investments. The World-Class Abitibi Greenstone Belt of Canada. Overview Several of the world’s largest gold and base metal deposits are found in eastern Canada’s Abitibi greenstone belt (AGB).

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Hydrothermal alteration, ore fluid characteristics, and ...

Tarmoola is a structurally controlled Archean orogenic gold deposit hosted in greenschist facies metamorphosed komatiite and trondhjemite in the Leonora district of the Eastern Goldfields province, Yilgarn craton. High-grade (>1 g/t Au) orebodies are located in komatiite wall rock adjacent to the eastern and northeastern margins of the asymmetrical, north-south-striking, Tarmoola trondhjemite ...

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Nanoparticle Formation in Confined Pores Spaces

2021-5-24  Gold nanoparticles and high-grade gold ore deposits Chromite nanoparticles during greenschist metamorphism. High grade gold deposits in the Abitibi greenstone belt, Canada. Gold-bearing Pyrite Pyrite Hastie et al. 2021 Communications Earth Environment. Hematite pyrite

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Mineralogical and Petrogenetic Study of Gold Ore from

2015-1-13  The Boddington copper-gold mine, located within the northern part of the Archaean Saddleback greenstone belt, Southwest Yilgarn Block, W.A. commenced production in July 2009 and is set to be Australia‟s largest gold mine, with gold reserves in excess of 26 Moz and capacity for an annual production of 35 million tonnes of ore.

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Main types of gold ore forming systems and their ...

Within the Taimyr - Severnaya Zemlya mineragenic province, the Late Paleozoic - Early Mesozoic Kara rare-metal - gold and Byrrangsky coal-bearing - polymetallic mineragenic areas are distinguished. Main geological commercial types of the Kara mineragenic area include manifestations of gold-quartz, gold sulphide-quartz (proper gold ore), and gold-rare metal, gold-bearing copper-molybdenum ...

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The structural controls of gold mineralisation within the ...

2007-3-9  craton, whereas greenschist-facies units as young as 2.55 Ga prevail towards the eastern part of the craton (Myers 1993). The EGP covers approximately the eastern third of the Yilgarn Craton, where the majority of gold deposits are located (Hagemann and Cassidy 2001). The Yilgarn Craton has been divided into a number of

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GREENSTONE/CHLORITE-SCHIST/GREENSCHIST

2012-3-21  Greenstone belts often contain important ore deposits of gold, silver, copper ore, zinc and lead. Well known examples of economically valuable greenstone belts have been mined in Canada, Australia, Africa and Brazil- and to a lesser extent in the United States.

More

Orogenic Gold Deposits: Genesis and Exploration

gold intrusions generally occur at, or within a few kilometers of the deposits. Greenschist to lower amphibolite metamorphic conditions, having been reached within a few tens of million years prior to ore formation, represent peak P-T conditions in the wallrocks for most deposits. However, orogenic gold deposits in eastern

More

greenschist Geology for Investors

2014-11-5  Make sense of mining company investments. The World-Class Abitibi Greenstone Belt of Canada. Overview Several of the world’s largest gold and base metal deposits are found in eastern Canada’s Abitibi greenstone belt (AGB).

More

Hydrothermal alteration, ore fluid characteristics, and ...

Tarmoola is a structurally controlled Archean orogenic gold deposit hosted in greenschist facies metamorphosed komatiite and trondhjemite in the Leonora district of the Eastern Goldfields province, Yilgarn craton. High-grade (>1 g/t Au) orebodies are located in komatiite wall rock adjacent to the eastern and northeastern margins of the asymmetrical, north-south-striking, Tarmoola trondhjemite ...

More

Nanoparticle Formation in Confined Pores Spaces

2021-5-24  Gold nanoparticles and high-grade gold ore deposits Chromite nanoparticles during greenschist metamorphism. High grade gold deposits in the Abitibi greenstone belt, Canada. Gold-bearing Pyrite Pyrite Hastie et al. 2021 Communications Earth Environment. Hematite pyrite

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U.S. DEPARTMENT OF THE INTERIOR DESCRIPTIVE, AND

2010-12-9  occur in gold-bearing compressive shear zones in Archean greenstone belts, and Late Proterozoic and Phanerozoic folded troughs of pelitic turbidites. The deposits occur mainly in the outer fringes of low-grade, greenschist fades metamorphic belts. The main ore-controlling structures are strike-slip and high-angle reverse faults. Common

More

Mineralogical and Petrogenetic Study of Gold Ore from

2015-1-13  The Boddington copper-gold mine, located within the northern part of the Archaean Saddleback greenstone belt, Southwest Yilgarn Block, W.A. commenced production in July 2009 and is set to be Australia‟s largest gold mine, with gold reserves in excess of 26 Moz and capacity for an annual production of 35 million tonnes of ore.

More

The World-Class Abitibi Greenstone Belt of Canada ...

2014-11-5  Overview. Several of the world’s largest gold and base metal deposits are found in eastern Canada’s Abitibi greenstone belt (AGB). The term world-class can sometimes be overused, but the AGB really earns the title, hosting 11 gold deposits over 100 tonnes, including one of the biggest deposits in the world, the >1000 t gold Hollinger-McIntyre deposits near Timmins, Ontario.

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The structural controls of gold mineralisation within the ...

2007-3-9  craton, whereas greenschist-facies units as young as 2.55 Ga prevail towards the eastern part of the craton (Myers 1993). The EGP covers approximately the eastern third of the Yilgarn Craton, where the majority of gold deposits are located (Hagemann and Cassidy 2001). The Yilgarn Craton has been divided into a number of

More

Lithological controls on structural evolution of ...

2018-6-16  direct examination of the gold itself within the sulfide-bearing rock. Gold-bearing sulfide minerals occur in a range of sites within the Hyde-Macraes Shear Zone, in quartz veins and disseminated in hydrothermally altered rocks without quartz veins (Craw et al. 1999). Ore at the Round Hill pit was dominated by quartz veins, with relatively ...

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GREENSTONE/CHLORITE-SCHIST/GREENSCHIST

2012-3-21  Greenstone belts often contain important ore deposits of gold, silver, copper ore, zinc and lead. Well known examples of economically valuable greenstone belts have been mined in Canada, Australia, Africa and Brazil- and to a lesser extent in the United States.

More

The mineralisation, alteration paragenesis and ...

The deposit is hosted within a greenschist facies metamorphosed and complexly deformed sedimentary package dominated by ironstone and intruded by diorite dykes. The gold mineralisation is spatially associated with the Geita Hill Shear Zone which, is a NE-trending, moderately west dipping deformation zone of discontinuous shear fractures.

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U.S. DEPARTMENT OF THE INTERIOR DESCRIPTIVE, AND

2010-12-9  occur in gold-bearing compressive shear zones in Archean greenstone belts, and Late Proterozoic and Phanerozoic folded troughs of pelitic turbidites. The deposits occur mainly in the outer fringes of low-grade, greenschist fades metamorphic belts. The main ore-controlling structures are strike-slip and high-angle reverse faults. Common

More

Mineralogical and Petrogenetic Study of Gold Ore from

2015-1-13  The Boddington copper-gold mine, located within the northern part of the Archaean Saddleback greenstone belt, Southwest Yilgarn Block, W.A. commenced production in July 2009 and is set to be Australia‟s largest gold mine, with gold reserves in excess of 26 Moz and capacity for an annual production of 35 million tonnes of ore.

More

Structures and Ore Genesis of the Grimsdalen Sulphide ...

2015-3-4  greenschist to amphibolite facies conditions. In this paper a model for the structural development is presented. It is shown that the concentration of the stratiform sulphides into ore bodies occurred during the first major deformation while the actual present-day location of the ore bodies is governed by the second phase of deformation.

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The structural controls of gold mineralisation within the ...

2007-3-9  craton, whereas greenschist-facies units as young as 2.55 Ga prevail towards the eastern part of the craton (Myers 1993). The EGP covers approximately the eastern third of the Yilgarn Craton, where the majority of gold deposits are located (Hagemann and Cassidy 2001). The Yilgarn Craton has been divided into a number of

More

GO-26 GO-26 19/02/15 15.14 Side 1 Assessment of

2020-9-10  This edition of Geology and Ore highlights the main results from the workshop, including descriptions of the most impor-tant orogenic gold provinces in Greenland. A recent geological review of orogenic gold provinces in southern West and South-West Greenland is given in Kolb et al. (2013), and a review on gold occur-

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Hydrothermal alteration styles in ancient and modern ...

2018-6-1  Alteration zones in host rocks around hydrothermal gold deposits are important for economic and scientific reasons. Altered rocks expand the width of the target zone at the ex-ploration stage, and well-defined alteration zones can provide vectors for ore (Bohlke 1988; EiluMikucki 1998; Bierlem Crowe 2000). Commonly, alteration zones ...

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Svaneti Gold Occurence (Kirar-Abakuri Ore Knot) and its ...

2019-8-9  known ore occurrences, which by geological, mineralogical and geochemical features belong to gold-quartz-low sulfide deposits. The article includes 1:50 000 scale geological maps of lukhra potential gold deposit and Kirar-Abakuri ore knot, and geological and mineralogical features of the deposit structure are taken into consideration.

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Wallrock alteration in the Bendigo gold ore field ...

2021-5-26  rains. The Bendigo ore field, Australia’s second largest goldfield, is located in central Victoria, 152 km NNW of Melbourne and covers an area of 45 km2. It produced approximately 22 million ounces of gold, 17 million ounces from reef mining, which is approximately 53% of the primary gold produced in Victoria. Mineralisation is mainly ...

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