Expanding the metamorphic devolatilization model: …
Deposits are also found in higher-grade metamorphic rocks, known as hypozonal gold deposits. These deposits are mostly hosted in amphibolite-facies rocks in greenstone belts and are characterized by high-temperature alteration assemblages such as garnet, diopside, hornblende, and K-feldspar and ore-forming temperatures as high as ~500–700 °C (Kolb et …
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Gold deposits in high grade metamorphic terrains, …
Hemlo, Challenger, Griffin's Find and Big Bell are well-studied examples of gold-only deposits where mineral assemblages have been recrystallised and timing relationships obscured due to high-grade …
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Distribution, character and genesis of gold deposits in metamorphic
Epigenetic gold deposits in metamorphic terranes include those of the Precambrian shields (approx 23,000–25,000 t Au), particularly the Late Archean greenstone belts and Paleoproterozoic fold belts, and of the late Neoproterozoic and younger Cordilleran-style orogens (approx 22,000 t lode and 15,500 t placer Au), mainly along the margins of Gondwana, …
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Distribution, Character, And Genesis of Gold Deposits in Metamorphic
The majority of gold deposits in metamorphic terranes are located adjacent to first-order, ... Grades and tonnages of gold ore in metamorphic belts. There are about 100 world-class gold deposits, which areconsidered here as defined by at least 70 t Au (Figs. 1,6; App.Table AI; Gosselin and DuM, 2005a, b), with 17 of thesebeing truly giants ...
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Distribution, Character, and Genesis of Gold Deposits in …
The majority of gold deposits in metamorphic terranes are located adjacent to first-order, deep-crustal fault zones, which show complex structural histories and may extend along strike for hundreds of kilometers with widths of as much as a few thousand meters.
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Orogenic gold: is a genetic association with magmatism …
Many workers accept a metamorphic model for orogenic gold ore formation, where a gold-bearing aqueous-carbonic fluid is an inherent product of devolatilization across the greenschist-amphibolite boundary with the majority of deposits formed within the seismogenic zone at depths of 6–12 km. Fertile oceanic rocks that source fluid and metal may be heated …
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Distribution, Character, and Genesis of Gold Deposits in …
Orogenic gold deposits formed in various terranes of most ages since the Paleoarchean and generally consist of quartz veins hosted in shear zones formed at the …
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Thesis | The lithogeochemical and mineral-chemical …
The lithogeochemical and mineral-chemical alteration footprints of the Canadian Malartic gold deposit, Québec: Implications for ore-vectoring in metamorphic terranes
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Metamorphic and Metamorphogenic Ore Deposits
The types of mainly metallic mineralization found in metamorphic terranes are reviewed and an attempt is made to define the genetic relations between the mineralization and the metamorphic events.The terms metamorphosed, metamorphic, and metamorphogenic as applied to ores are also considered.The development of thought and the history of …
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Formation of the intrusion-hosted orogenic-type gold lodes: …
Unlike the gold deposits typically hosted in metamorphosed volcanic-sedimentary sequences, the recently discovered Axile gold deposit (over 13 t Au at 5.35 g/t) is a unique …
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The Boring Billion: A key to resolving controversy on ore
Orogenic gold systems are arguably the most variable mineral system globally in terms of an extreme range of depositional depths, corresponding P–T conditions and wallrock alteration assemblages, structural controls and styles, and element associations. This diversity has ignited controversy on genetic models for the two decades since orogenic gold became a …
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Geological and geochemical characterization of the Nanlia …
Gold deposits in metamorphic terranes are the major source of gold in the world, contributing to more than one third of global reserves (Frimmel, 2008). This class of gold deposits has formed for more than 3 billion years of Earth's history, from the Mesoarchean to Proterozoic, and continuously throughout the Phanerozoic (Goldfarb et al ...
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Geology of the Yindongpo gold deposit
Phanerozoic orogenic gold deposits worldwide are commonly considered to be formed from metamorphic devolatilization of marine carbonaceous sedimentary rocks. Here we show that the Yindongpo gold deposit from the Qinling orogen (central China) is genetically associated with the metamorphism of volcanic rocks during the late Paleozoic orogeny, which involved the closure …
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(PDF) Gold mineralization in a high grade …
A few known gold deposits found in high grade metamorphic terranes include those in the Yilgarn craton in Australia, Renco in Zimbabwe, Hemlo in Canada and the recently discovered Handeni deposit in Tanzania.
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Gold Deposits in Metamorphic Rocks: What We …
Orogenic gold deposits represent the main source of gold in the world's deformed Phanerozoic-Neoproterozoic metasedimentary or Paleoproterozoic-Archean metavolcanic terranes, typically having formed 20 …
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Gold Deposits in Metamorphic Belts: Overview of
Gold deposits with atypical metal associations are a particularly diverse and controversial group, are most abundant in Late Archean terranes, and include several world …
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Gold‐quartz veins in metamorphic terranes and their …
Gold-quartz vein fields in metamorphic terranes such as greenstone belts provide evidence for the involvement of large volumes of fluids during faulting and may be products of seismic processes near the base of the seismogenic regime.
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A scale-integrated exploration model for orogenic gold …
Strong metamorphic gradients dominated by low-P Barrovian metamorphic terranes: ... flux into dilation and other damage zones along suitably-aligned pre-existing structures and deposition of high-grade gold ores within those structures and more disseminated mineralization and alteration zones adjacent to them.
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Gold Ore
Gold ore refers to a natural material containing gold in its elemental form or as an alloy, often found in association with telluride minerals. ... The Mother Lode District of California may be the most famous of a class of lode gold-ore deposits that are found in metamorphic terranes associated with accretionary plate tectonics. They have also ...
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Gold Deposits in Metamorphic Belts: Overview of …
rich ore fluids from the relatively shallow level granitoids implicated as ore-fluid sources. Gold deposits with atypical metal associations are a particularly diverse and controversial group, are most ... the final geometry of the metamorphic terranes within the orogenic belts in which they reside. Gold deposits that formed in this metamorphic ...
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Distribution, Character, and Genesis of Gold Deposits in …
This work expands the P-T range of the metamorphic devolatilization model and enhances its robustness in explaining gold mineralization in metamorphic terranes.
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Gold Deposits in Metamorphic Belts: Overview of
Current unknowns for orogenic gold deposits include the following: (1) the precise tectonic setting and age of mineralization in many provinces, particularly in Paleozoic and older metamorphic belts; (2) the source of ore fluids and metals; (3) the precise architecture of the hydrothermal systems, particularly the relationship between first ...
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Transport and Precipitation of Gold in Phanerozoic …
This study reports results of mass transfer calculations using chemical modeling software (HCh) to determine chemical parameters that may have had a significant effect on …
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Orogenic gold deposits: A proposed classification in the …
The so-called `mesothermal' gold deposits are associated with regionally metamorphosed terranes of all ages. Ores were formed during compressional to …
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