Komatiite - Wikipedia
网页Komatiite / koʊˈmɑːtiˌaɪt / is a type of ultramafic mantle -derived volcanic rock defined as having crystallised from a lava of at least 18 wt% magnesium oxide (MgO). [1] It is classified as a 'picritic rock'. Komatiites have low silicon, potassium and aluminium, and high to extremely high magnesium content.
The discovery and petrogenetic significance of komatiites
网页2023年9月1日 · Komatiites are in places associated with spinifex textures (elongated bladed and plumose olivine crystals). The discovery and petrological study of komatiites and understanding of the field controls have given rise to intense debate about their mantle origin, water content and geodynamic setting of eruption.
Geological evidence for high H2 production from komatiites in the ...
网页2023年11月6日 · Komatiites are highly magnesian lavas, which contain evidence of extensive serpentinization and magnetite (Fe 2+ Fe 3+2 O 4) production close to the Archaean seafloor. H 2 production in...
(PDF) Komatiites: their geochemistry and origins - ResearchGate
网页2023年7月27日 · Komatiites are ultra-hot ultramafic lavas, largely restricted to the Archaean. They represent an extreme endmember of terrestrial magmatism and challenge our understanding of how mantle melting...
Komatiite - an overview | ScienceDirect Topics
网页Komatiite is the signature rock type of Archean greenstone belts and is found across almost the entire age span of Archean crust. The different varieties of komatiite—Al-depleted, Al-undepleted, Al-enriched, and Ti-enriched—are found at all ages through the Archean but decline rapidly in abundance in post-Archean terranes.
The komatiite testimony to ancient mantle heterogeneity
网页2022年4月5日 · Komatiites are crystallized samples of high-temperature, high-MgO lavas that were common during the Archean, but became increasingly rarer in the Proterozoic and Phanerozoic.
Komatiites reveal a hydrous Archaean deep-mantle reservoir
网页2016年3月30日 · Archaean komatiites (ultramafic lavas) result from melting under extreme conditions of the Earth’s mantle. Their chemical compositions evoke very high eruption temperatures, up to 1,600 degrees ...
Review komatiites: from Earth’s geological settings to ... - Springer
网页2007年2月15日 · 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.
Komatiite - SpringerLink
网页2021年3月11日 · Komatiite is a volcanic rock of ultramafic composition. It is distinguished from the more common basaltic magma by a higher content of MgO (>18%) and correlated low contents of most other elements. Overview. Komatiite is relatively common in Archean greenstone belts, rare in Proterozoic belts, and virtually absent in younger regions.
Komatiite - SpringerLink
网页Komatiite is a volcanic rock of ultramafic composition. It is distinguished from the more common basaltic magma by a higher content of MgO (>18%) and low contents of most other elements. Overview. Komatiite is relatively common in Archean greenstone belts, rare in Proterozoic belts, and virtually absent in younger regions.