fractional segregation and ore genesis

Higher Melt Fractions are Generated in Metamorphosed ...

Felsic magma-related ore deposits are Earth''s largest source of Cu and Mo, and a major source of Au. Despite this, there have been few field-based studies of processes that affect metal distribution in magma source regions. Based on geochemical studies at ore deposits, it has been suggested that in magmatic arcs, magmas and metal may be derived from subducted oceanic slab, overlying ...

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Dynamics of Magmatic Sulphide Droplets during Transport in ...

The accumulation of this phase in specific depositional environments is the essential process in the formation of magmatic ore deposits of Ni, Cu and platinum group elements (PGE), some of which, such as those at Sudbury in Canada and Noril''sk–Talnakh in arctic Russia, constitute some of the world''s most valuable ore bodies ( Naldrett ...

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(PDF) The Role of Fractional Crystallization and Magma ...

The Role of Fractional Crystallization and Magma Mixing/Mingling in the Genesis of Karacaali Magmatic Complex (Central Anatolia, Turkey) Fe, Mo-Cu Mineralizations ... character of granites and ore ...

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Modern Concepts of Ore Genesis

THEORIES OF ORE DEPOSIT GENESIS. Origin Due to Internal Processes. Magmatic Segregation. Separation of ore minerals by fractional crystallization during magmatic differentiation. Pt-Cr deposits Bushveld, S.A. Titanium deposit Tahawas, N.Y. Liquid immiscibility.

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The Giant Jinchuan Ni-Cu-(PGE) Deposit: Tectonic Setting ...

 · The Giant Jinchuan Ni-Cu-(PGE) Deposit: Tectonic Setting, Magma Evolution, Ore Genesis, and Exploration Implications Author(s) ... undepleted high Mg basaltic magma are consistent with previous sulfide segregation at depth. ... how this varies as a function of partial mantle melting and subsequent fractional crystallization, (2) the ...

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Tempo of magma degassing and the genesis of porphyry ...

 · The genesis of the largest deposits is favoured by various factors, including long-lived magmatic-hydrothermal activity, high concentrations of "ore ingredients" (i.e., copper and sulphur) in ...

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Quantitative Modelling of the Segregation of Magmatic ...

genesis of the Deccan basalts Of India. graduation Wilh his ... ed contrast IV samples from ''he ore-bearing disfncts of ... Batch equilibration, Fractional segregation. presence of economic of ...

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Mineral chemistry and genesis of the Permian Cihai and ...

 · Many mechanisms have been proposed to explain the petrogenesis of mafic-related iron ore deposits including gravity segregation (Emmons, 1904, Charlier et al., 2006), fractional segregation (Obsorne, 1959, Cawthorn and McCarthy, 1980), magma mixing, assimilation or contamination (Harney et al., 1990), magma immiscibility (Duchesne, 1999 ...

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Theories of Ore genesis 3

Concept • An Ore mineral is mostly a non-silicate mineral • Most ores are sulphide, some are oxides, native metals. • Industrial minerals may occur as silicate • Ore genesis ~ similar to formation of rocks • 2 main processes • i) Internal / igneous processes; • ii) External / surface processes • Ores are mostly sulphides and oxides whereas rocks are mostly silicates; hence ...

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Ore-forming adakitic porphyry produced by fractional ...

Adakitic intrusions are supposed to have a close genetic and spatial relationship to porphyry Cu deposits. However, the genesis of adakitic intrusions is still under dispute. Here, we describe newly discovered intrusive complex rocks, which are composed of ore-bearing, layered magnetite-bearing gabbroic and adakitic rocks in Jiamate, East Junggar, NW China.

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Minerals | Special Issue : Ore Genesis and Metamorphism ...

 · The forecast and detection of genesis and multiple stages of various ore deposits is one of the main objectives in different fields of present-day geosciences. This Special Issue will focus on the latest achievements in geochemistry, mineralogy, and geochronology of ore and metamorphic complexes, their relations, and forecasting potential for ...

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SIMULATION OF PARTICLE SEGREGATION IN …

segregation that takes place in the bed, induced by the granular flow pattern (c) segregation induced by gas-solid interaction, e.g. near the so-called raceway (a zone of partial fluidization due to gas injection). Segregation will lead to different segregation patterns and thus different grain size distributions.

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Large-scale liquid immiscibility and fractional ...

Immiscibility is a potential mechanism for the formation of high-Fe-Ti-P rocks; however, whether large-scale segregation and eruption of high-Si lavas can occur in nature has yet to be proven. In this study, we investigate the possibility of immiscibility between the cogenetic 1780 Ma high-Fe-Ti-P-bearing Taihang dykes and the ''bimodal'' Xiong''er volcanics in North China.

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Igneous differentiation

Fractional crystallization and accumulation of crystals formed during the differentiation process of a magmatic event are known as cumulate rocks, ... Fractional crystallization is the removal and segregation from a melt of mineral precipitates, ... These "pneumatolytic" processes are of the first importance in the genesis of many ore deposits ...

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Re-Os Isotope Systematics of the Voisey''s Bay Ni-Cu-Co ...

Ore Genesis, and Metal Redistribution DAVID D. LAMBERT,†,* LOUISE R. FRICK, ... magmas that were the end product of sulfide saturation and segregation during the early stages of mineralization. More internally consistent R factors (50–500) are obtained if the ... significant fractional crystallization and crustal contamination in the deep ...

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Magmatic origin of giant ''Kiruna-type'' apatite-iron-oxide ...

 · Iron is the most important metal for modern industry and Sweden is by far the largest iron-producer in Europe, yet the genesis of Sweden''s main iron-source, the ''Kiruna-type'' apatite-iron ...

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ore genesis : definition of ore genesis and synonyms of ...

Ore genesis processes. Evans (1993) divides ore genesis into the following main categories based on physical process. These are internal processes, hydrothermal processes, metamorphic processes and surficial processes. Internal processes. Fractional crystallization: separates ore and non-ore minerals according to their crystallization ...

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Mantle-derived magmas and magmatic Ni-Cu-(PGE) deposits

generation or segregation of an immiscible sulfide melt. 3)!The sulfide melt interacts dynamically with a much larger mass of silicate magma, a process that increases the tenors of ore metals, especially for highly chalcophile elements. 4)!Finally, the metal-rich sulfide liquid accumulates in sufficient quantity to form an economic deposit.

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Genesis of Intermediate and Silicic Magmas in Deep Crustal ...

The Genesis of Intermediate and Silicic Magmas in Deep Crustal Hot Zones ... from near (newly injected sill near Moho) to 0% (old sill injected into lower crust). The fraction of crustal melt varies throughout the hot zone according to the age and proximity of the basalt sills. ... because the timescales are too short to permit significant ...

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DIVISION OF MINES AND MINING Sheldon L. Glover, …

Magnetite occurs as a magmatic segregation in peridotite - in some places as disseminated grains and in others as the principal constituent. The best ore (mostly oxidized to hematite) is in a zone 8 to 10 feet wide and a hundred or so feet long adjacent to a diabase dike. Two or

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Rock and Mineral Resources | Geology

Ore Genesis Processes Endogenous Magmatic Processes. Fractional crystallization: separates ore and non-ore minerals according to their crystallization temperature. As early crystallizing minerals form, they incorporate certain elements, some of which are metals. These crystals may settle onto the bottom of the intrusion, concentrating ore ...

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Minerals | Special Issue : The Formation of Sulfide Ores ...

 · Two stages of sulfide segregation have been recognized. Early segregation led to the depletion of platinum group elements (PGE), and disseminated sulfide mineralization was the product of later segregation. The assimilation of crustal Si and S components played more important roles on sulfide segregation rather than fractional crystallization.

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Compositional variations of olivine from the Jinchuan Ni ...

 · The absolute values differ, but the zoning pattern across the ore body indicated by actual analyses and modeled results are consistent. The weighted average contents of Ni in the sulfide fractions in the lower, central and upper zones of ore body #1 intercepted by II14–83 are 8.7, 9.3, and 6.5 wt%, respectively (data from De Waal et al. 2003).

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ORE DEPOSITION ASSOcIATED wITH MAGMAS

SOcIETY OF EcONOMIc GEOLOGISTS, INc. ORE DEPOSITION ASSOcIATED wITH MAGMAS CONTENTS PART I: MAFIC ROCKS Introduction: Magmatic Deposits Associated with Mafic Rocks A.J. Naldrett Sulfide Melts: Crystallization Temperatures, Solubilities in Silicate Melts, A.J. Naldrett and Fe, Ni, and Cu Partitioning Between Basaltic Magmas and Olivine

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Genesis of the main types of sulphide ore in the Jinchuan ...

The Jinchuan Ni‐Cu‐PGE deposit is one of the three largest magmatic Ni deposits in the world. Disseminated, net‐textured, Cu‐rich sulphide ores and massive sulphide ores are the most important ore ...

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Modern Concepts of Ore Genesis

THEORIES OF ORE DEPOSIT GENESIS. Origin Due to Internal Processes. Magmatic Segregation. Separation of ore minerals by fractional crystallization during magmatic differentiation. Pt-Cr deposits Bushveld, S.A. Titanium deposit Tahawas, N.Y. Liquid immiscibility.

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Processes of Ore Formation

THEORIES OF ORE DEPOSIT GENESIS. Origin Due to Internal Processes . Magmatic Segregation. Separation of ore minerals by fractional crystallization during magmatic differentiation. Pt—Cr deposits Bushveld, S.A. Titanium deposit Tahawas, N.Y. Liquid immiscibility.

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Economic geology

 · Many parameters influence the ore accumulation processes, these are: 1.the depth of intrusion, 2.tectonic activities, 3.the temperature gradient in space and time, 4 actional crystallization, 5.dynamics of the melt body (e.g. convective flow), 6.repeated injection of fresh melt, assimilation of country rocks, 7 lphur or external fluids, 8 ...

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Phase Transformations and Genesis of Platinum-Group ...

in three ways. These are (1) fractional separation of PGE during magma crystallization; (2) PGE concentration in the oxide-ore phase forming segregations; (3) PGE extraction from magma into immiscible sulfide liquids. PGE concentration in mafic-ultramafic igneous rocks varies substantially from one to several tens of ppb and only rarely do

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Ore genesis

The various theories of ore genesis explain how the various types of mineral deposits form within the Earth''s crust.Ore genesis theories are very dependent on the mineral or commodity.. Ore genesis theories generally involve three components: source, transport or conduit, and trap.

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(PDF) Secondary Ore Formation Theories

Ex. Mississippi Valley-type Deposits. The process which belong to the above two processes can be summarized as follows. THEORIES OF ORE DEPOSIT GENESIS Origin Due to Internal Processes Magmatic Separation of ore minerals by fractional Pt—Cr deposits Segregation crystallization during magmatic differentiation.

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Horizontal and vertical variations in noble-metal ...

 · Chemical Geology, 88 (1990) 279-300 279 Elsevier Science Publishers B.V., Amsterdam Horizontal and vertical variations in noble-metal distribution in the Great Dyke of Zimbabwe: A model for the origin of the PGE mineralization by fractional segregation of sulfide" A.J. Naldretta and A.H. Wilsonb aDepartment of Geology, University of Toronto, Toronto, Ont. M5S 3B I (Canada) aDepartment of ...

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