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

 — Komatiites are highly magnesian lavas, which contain evidence of extensive serpentinization and magnetite (Fe2+Fe3+2O4) production close to the Archaean seafloor. H2 production in komatiitic ...

 — The mineralogy of unaltered komatiites is remarkably simple. Only olivine crystallizes abundantly and its composition is tied closely to that of the komatiite liquid. During the early stages of crystallization, chromite, and in some cases Ni–Fe sulfides, accompany olivine, but they are normally very minor components.

 — The existence of Archaean komatiites with eruption temperatures greater than 1650°C requires that the mantle be vertically differentiated by the time of komatiite eruption. If in the unlikely event that undifferentiated mantle had survived primordial planetary differentiation and had been hot enough to deliver 1650°C komatiite, it would have ...

Komatiites erupted billions of years ago as pulsating streams of white-hot lava. Their unusual chemical compositions and exceptionally high formation temperatures produced highly fluid lava that crystallized as spectacular layered flows. Investigation of the extreme conditions in which komatiites formed provides important evidence about the ...

 — Petrography and geochemistry of Mesoarchaean komatiites from the eastern Iron Ore belt, Singhbhum craton, India, and its similarity with 'Barberton type komatiite' ... After crushing in a metal jaw crusher, all samples were ground in an agate ball mill. Major and trace elements were analyzed at the Activation Laboratories Ltd. (Ancaster, ...

 — The reconstructed primary Archean komatiites exhibited high MgO content, ranging from 25 to 31 wt.%, while the primary Phanerozoic plume-derived magmas contained 12–25 wt.% MgO.

 — Petrography and geochemistry of Mesoarchaean komatiites from the eastern Iron Ore belt, Singhbhum craton, India, and its similarity with 'Barberton type komatiite' ... After crushing in a metal jaw crusher, all samples were ground in an agate ball mill. Major and trace elements were analyzed at the Activation Laboratories Ltd. (Ancaster, ...

 — Komatiites provide insight into Archaean mantle sources and surface processes that were not present in later stages of Earth's evolution. They were …

 — Combined with the availability of gold and mineralogically bound water in hydrated komatiites, metamorphic devolatilization of komatiites can well account for hypozonal gold mineralization in amphibolite-facies rocks, as well as the close temporal and spatial association between hypozonal gold and komatiites in greenstone belts.

 — Komatiites in the SDZ experienced greenschist facies metamorphism and relatively minor aqueous alteration, with ∼75% of their olivine phenocrysts preserved ... were cut into slabs, abraded on the cut surfaces using SiC sandpaper to remove saw marks, crushed in an alumina jaw crusher, and finely ground using an alumina …

The uniform chondritic Os isotopic composition of the Kidd-Munro komatiites contrasts with the typical large-scale Os isotopic heterogeneity in the mantle sources for ca. 89 Ma komatiites from the Gorgona Island, …

Summary. Introduction. There are two main types of ore deposits associated with komatiites: primary magmatic sulfide deposits, mined chiefly for their nickel content with …

komatiites, called "Al-undepleted" or Munro-type, has near chondritic ratios of Al2O3/TiO2 and Gd/Yb. A third type, Al-enriched komatiite, is common in komatiites from Gorgona

 — We construct a model for the komatiites from adiabatic melting of the mantle source to fractional crystallization at crustal conditions. Using MELTS, we calculate three …

 — 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 ...

 — Komatiites are ultramafic lavas containing more than 18% MgO in the parental liquid (Arndt and Nisbet, 1982). To be classified as a komatiite, the crystallized lava must either contain spinifex texture, or be genetically related to lavas containing spinifex texture. Spinifex texture is a crucial feature that distinguishes komatiites from other ...

 — 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 …

Komatiites are ultramafic mantle-derived volcanic rocks. They have low SiO 2, low K 2 O, low Al 2 O 3, and high to extremely high MgO.. Komatiites were named for their type locality along the Komati River in South Africa. True komatiites are very rare and essentially restricted to rocks of Archaean age and most are greater than two billion years old, …

Komatiite - July 2008. Introduction. There are two main types of ore deposits associated with komatiites: primary magmatic sulfide deposits, mined chiefly for their nickel content with minor by-product Cu and PGEs, and secondary laterite deposits enriched in nickel and cobalt, developed over thick olivine cumulate units, the latter known thus far only in the …

 — 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 ...

Komatiites. Komatiites were first recognized in the late 1960s in the Barberton Mountainland greenstone belt in South Africa (Viljoen & Viljoen, 1969a,b).They have extremely high MgO contents; 18-30 wt.% compared to 10-15 wt.% for the most mafic mid-ocean ridge basalts (MORB) or ocean-island basalts (OIB, Figure 1).

Differing conditions produce a spectrum of ultramafic magma types. Komatiites form by high degrees of melting, at great depths, of an essentially anhydrous source. Barberton-type komatiites are moderately high degree melts from a particularly hot and deep source; Munro-type komatiites are very high degree melts of a slightly cooler source ...

 — 1. Introduction. Komatiites are high magnesian, low alkali, predominantly Archean ultramafic extrusive rocks, and are important in understanding the lower mantle processes in early Earth (Arndt et al., 2008; Dostal, 2008; Furnes et al., 2013; Hanski et al., 2001; Le Bas, 2000; Viljoen and Viljoen, 1969).Quenched from very high temperature …

LIPs and lavas with deep mantle sources have compositions ranging from komatiites found in Archean greenstone belts to basalts and picrites in Phanerozoic flood basalt and recent oceanic islands. In this study, we identify the mantle conditions appropriate to each type of lava based on an experimental study of the melting of pyrolite. The depth ...

Komatiites are not exclusively related to the early Earth, as they may resemble some geological features of other planetary bodies of the Solar System, particularly on Io, and could help us to understand some extraterrestrial volcanisms. Such a prospect opens the idea that komatiites might be more common in the Solar System and also that the ...

 — Rare examples of Phanerozoic komatiites are found in the Song Da zone, NW Vietnam. These komatiites were erupted through continental crust and may belong to the SE extension of the Permo-Triassic Emeishan volcanic province located in SW China. They provide a good opportunity to study the source characteristics of starting plume …

Komatiites represent primitive mantle melts and require high degree partial melting of the mantle (up to 50 %) (Nesbitt & Sun 1976, Sun & Nesbitt 1978). The formation of komatiites has generally been attributed to mantle plume upwelling and related volcanism in a variety of geodynamic settings mainly during the Archean and early Proterozoic ...

 — Komatiites are igneous rocks mainly of Archaean age. Their ultramafic origin is controversial and has been attributed to either high degrees of dry melting of peridotite in deep mantle plumes at temperatures up to 500°C hotter than today, or to melting at shallow depth, in volatile-rich (hydrous) mantle with temperatures not much different than the …

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 ...