0086-21-58386256

Komatiites and Ni-Cu-PGE deposits | Geology for Investors

Komatiites are exclusive ancient rock types which exhibit a unique spinifex texture. The Ni-Cu-PGE mineralisation generally occurs as massive sulfide ore at the floor of the komatiitic flow or as disseminated sulfides through olivine-rich layers. It is worth noting that the critical features whether the mineralisation will occur are the flow ...

WhatsApp: +86 18221755073

Platinum group element geochemistry of komatiites from the …

Platinum group element geochemistry of komatiites from the Alexo and Pyke Hill areas, Ontario, Canada 1. ... and crushed in an alumina-faced jaw crusher. A 100- to 150-g aliquot of crushed sample was ground in an alumina shatter box and finely reground in an alumina-faced disk mill, and was used for the geochemical studies. The rest of the ...

WhatsApp: +86 18221755073

Deep mantle origin of large igneous provinces and komatiites

A broad range of primitive lavas. Mafic-ultramafic tholeiitic lavas such as basalts, picrites, and komatiites represent the deepest and hottest magmas that erupted on Earth.Three main families of komatiites are distinguished depending on their chemical composition; nicknames have been given to them according to locality of the main outcrops (): Al-depleted komatiites …

WhatsApp: +86 18221755073

Highly siderophile element systematics of the early Archean …

Ruth Well komatiites were derived from deep mantle melting in the majorite stability field, which resulted in depletions in Al and heavy REE. This source was also depleted in highly incompatible lithophile trace elements. 2.2. Hypothesis 2. The mantle source of the Ruth Well komatiites evolved with long-term chondritic Re/Os. 2.3. Hypothesis 3

WhatsApp: +86 18221755073

Nickel isotope fractionation in komatiites and associated sulfides …

The case for Ni isotopes is more complex, and fractionations have been previously thought to be small and restricted to continental weathering (Cameron and Vance, 2014; Ratié et al., 2015) or biological processes such as methanogenesis (Cameron et al., 2009).While no significant Ni isotope fractionation has been reported due to fractional crystallization or partial …

WhatsApp: +86 18221755073

Crystallochemistry and origin of pyroxenes in komatiites

Textures of komatiites from the Alexo area. a A scanned thin section of a random olivine spinifex-textured lava (sample M662). Olivine crystals (in white) are randomly oriented and lie in a fine-grained matrix.b Polished slab of coarse platy olivine spinifex textured lava, sample Ax105. Large complex dendritic grains of olivine (black, serpentinized) enclose a cell within …

WhatsApp: +86 18221755073

Expanding the metamorphic devolatilization model: Komatiites as …

The hydrated komatiites undergo metamorphic devolatilization through a series of dehydration reactions, some of which take place at temperatures beyond the greenschist- to amphibolite-facies transition (e.g., chlorite breakdown at ~800 °C; Hartnady et al., 2022).

WhatsApp: +86 18221755073

The discovery and petrogenetic significance of komatiites

Komatiites were first discovered by Richard and Morris Viljoen in the Barberton greenstone belt of South Africa and proposed as a new class of ultramafic volcanic rock with …

WhatsApp: +86 18221755073

(PDF) Komatiites

Komatiites are ultramafic volcanic rocks that occur mainly in Archean and Paleoproterozoic greenstone belts. These olivine-rich rocks are assumed to have crystallized from magmas that have about ...

WhatsApp: +86 18221755073

Geochemistry of a komatiitic, boninitic, and tholeiitic …

Komatiites and komatiitic basalts in the Abitibi greenstone belt exhibit pronounced spatial and temporal variations in major and trace element geochemistry that provide important constraints on their petrogenesis and tectonic setting. ... …

WhatsApp: +86 18221755073

Review komatiites: from Earth's geological settings to

Komatiites are fascinating volcanic rocks. They are among the most ancient lavas of the Earth following the 3.8 Ga pillow basalts at Isua and they represent some of the oldest ultramafic magmatic rocks preserved in the Earth's crust at 3.5 Ga. This fact, linked to their particular features (high magnesium content, high melting temperatures, low dynamic …

WhatsApp: +86 18221755073

Chromite in Komatiites, 1. Magmatic Controls on Crystallization …

Introduction. A large body of data exists in the literature describing chromites from ophiolites, layered intrusions, kimberlites, basalts and other provenances, but relatively few studies have looked systematically at chromite in komatiites (e.g. Zhou & Kerrich, 1992).This is the first in a series of papers which addresses the occurrence of chromite in komatiites and its …

WhatsApp: +86 18221755073

Intraplate origin of komatiites inferred from trace elements in …

remarkably fresh, 2.7-Gyr-old komatiites have been discovered, which contain unaltered olivine crystals and small glass inclusions 1• We report ion micoprobe data for 25 trace elements from these

WhatsApp: +86 18221755073

Contrasting komatiite belts, associated Ni–Cu–(PGE) deposit …

komatiites is metasomatic introduction or depletion of elements during metamorphic and/or hydrothermal fluid–rock interaction. In the Agnew–Wiluna greenstone belt, some portions of …

WhatsApp: +86 18221755073

Secular mantle oxidation across the Archean-Proterozoic …

The oxygen fugacities of nine mantle-derived komatiitic and picritic systems ranging in age from 3.55 Ga to modern day were determined using the redox-sensitive partitioning of V between liquidus olivine and komatiitic/picritic melt.

WhatsApp: +86 18221755073

Ni-Cu-PGE Metallogenesis of Komatiitic Rocks in the Abitibi …

Komatiites in the Pacaud assemblage are Ti-depleted komatiites (TDK) with high AbO31TiOz (25-35) and low [Gd/Yb]c~ (-0.6) (CN: chondrite normalized using values from McDonough and Sun, 1995), suggesting a garnet-rich source or formation via dynamic melting similar to Gorgona komatiites (Arndt et al., 1997).

WhatsApp: +86 18221755073

Chromite composition as evidence of metamorphism in …

Archaean komatiites of the greenstone belt in Manica area, western Mozambique contains accessory amount of disseminated chromite grains. The komatiite rocks comprise peridotitic and basaltic komtiite. These komatiites are affected by regional metamorphism as …

WhatsApp: +86 18221755073

Geochemistry of a komatiitic, boninitic, and tholeiitic basalt

Samples were crushed with a steel jaw crusher at the University of Western Australia to a size of 0.2–2 ... komatiites, tholeiitic basalts, and boninites. Komatiites have been subdivided into Al-undepleted (AUK, or Munro-type) and Al-depleted (ADK, or Barberton-type) varieties, and ADK into Al-depleted and Al-depleted–Ti-enriched subtypes ...

WhatsApp: +86 18221755073

Source composition or melting effect: New evidence from Archean

Komatiites are primarily extrusive volcanic rocks with high MgO contents (>18 %) that formed mainly during the Precambrian, especially during the Archean Era, and are …

WhatsApp: +86 18221755073

(PDF) Komatiites

Komatiites are ultramafic volcanic rocks that occur mainly in Archean and Paleoproterozoic greenstone belts. These olivine-rich rocks are assumed to have crystallized …

WhatsApp: +86 18221755073

(PDF) Application of lithogeochemistry in the assessment of nickel

Geochemical data from this study indicate that Paleoproterozoic komatiites in the Pulju Greenstone Belts and Archean komatiites in the Enontekiö area are prospective for nickel-sulphide ...

WhatsApp: +86 18221755073

The origin of spinifex texture in komatiites | Nature

Many komatiites, including the exceptionally fresh and well exposed flows at Pyke hill in Munro township, northeastern Ontario, erupted as subaqueous lava flows 1,4.The thermal effect of seawater ...

WhatsApp: +86 18221755073

Chromite in Komatiites, II. Modification during Greenschist …

JOURNAL OF PETROLOGY VOLUME 41 NUMBER 3 PAGES 387–409 2000 Chromite in Komatiites, II. Modification during Greenschist to Mid-Amphibolite Facies Metamorphism STEPHEN J. BARNES CSIRO EXPLORATION ...

WhatsApp: +86 18221755073

Platinum group element geochemistry of komatiites from the …

Many komatiites are interpreted to have ascended through continental crust and to have flowed tens of km from their eruptive sites (Lesher et al., 1984; Arndt, 1986b; Hill et al., 1995; Lesher …

WhatsApp: +86 18221755073

Sulfur isotopes in Archaean crustal reservoirs constrain the …

Assimilation and prolonged suspension of crust-derived sulfide liquid in komatiites are essential to form Ni-rich mineralisation. Evaluating the spatial relationship between komatiite-hosted Ni mineralisation and crustal S sources may thus provide insights into mechanisms of transport, metal enrichment and deposition of assimilated sulfide liquid. This study applied …

WhatsApp: +86 18221755073

Alteration patterns linked to high-grade gold mineralization at the

Whole rock samples were crushed using a steel jaw crusher and small chips (3–15 mm) were then separated and washed in an ultrasonic cleaner for 10 min. Clean chips were then dried and milled using agate or mild steel mills. ... Komatiites appear further to the east, and these komatiites have been intruded by granitoids, which are in turn ...

WhatsApp: +86 18221755073

Source composition or melting effect: New evidence from Archean

The use of komatiites to characterize the abundance and distribution of HSE in the early mantle critically depends on developing a better understanding of the partitioning behaviors of these …

WhatsApp: +86 18221755073

Sulfur isotopes in Archaean crustal reservoirs constrain the …

Assimilation and prolonged suspension of crust-derived sulfide liquid in komatiites are essential to form Ni-rich mineralisation. Evaluating the spatial relationship between komatiite-hosted Ni mineralisation and crustal S sources may thus provide insights into mechanisms of transport, metal enrichment and deposition of assimilated sulfide liquid.

WhatsApp: +86 18221755073

Contrasting komatiite belts, associated Ni–Cu–(PGE) deposit …

komatiites and hence promoting ore genesis (Lesher et al. 2001). However, this study questions the role of crustal ... a ceramic-faced jaw crusher. A 100–150 g aliquot of crushed sample was ground in an agate mill and was used for geochemical studies. Figure 2 (a) Simplified geological map of the Mt Keith domain, showing the location of the ...

WhatsApp: +86 18221755073

sbm mining gold quartz rock in komatiites crusher for sale.md · …

About GitLab GitLab: the DevOps platform Explore GitLab Install GitLab Pricing Talk to an expert /

WhatsApp: +86 18221755073

Solutions