Olivines in main-group pallasites: magma-ocean cumulates or partial melting residues?
نویسندگان
چکیده
منابع مشابه
Geochemistry and oxygen isotope composition of main-group pallasites and olivine-rich clasts in mesosiderites: Implications for the “Great Dunite Shortage” and HED-mesosiderite connection
Evidence from iron meteorites indicates that a large number of differentiated planetesimals formed early in Solar System history. These bodies should have had well-developed olivine-rich mantles and consequentially such materials ought to be abundant both as asteroids and meteorites, which they are not. To investigate this “Great Dunite Shortage” we have undertaken a geochemical and oxygen isot...
متن کاملبررسی واکنش گدازه/سنگ، ذوببخشی و خاستگاه پریدوتیتهای کرمانشاه به کمک شواهد بافتی و شیمی کانی
The Kermanshah ophiolite complex is located in outer Zagros ophiolitic belt and consists of both mantle and crustal suites as remnants of southern branch of the Neo-Tethys Ocean in Iran. Chemical composition determinative diagram of minerals indicates that olivine in dunite, harzburgite and lherzolites has forsteritic composition and in wherlitic rocks is chrysolite in composition likewise orth...
متن کاملNew oxygen isotope evidence for the origin of mesosiderites and main group pallasites
Introduction: Many groups of differentiated achondrites display limited oxygen isotope variation, plotting within a restricted portion of the three-isotope diagram immediately below the terrestrial fractionation line [1,2]. As a consequence, oxygen isotopes have until recently been of only limited value in deciphering the relationships between these meteorite groups. A case in point is the appa...
متن کاملMain-group pallasites: Thermal history, relationship to IIIAB irons, and origin
We have determined metallographic cooling rates below 975 K for eight main group (MG) pallasites from Ni profiles across taenite lamellae of known crystallographic orientation in metallic regions with Widmanstätten patterns. Comparison with profiles generated by modeling kamacite growth gave cooling rates ranging from 2.5 to 18 K/Myr. Relative cooling rates were also inferred from the sizes of ...
متن کاملA Self-Consistent Model of Melting, Magma Migration and Buoyancy-Driven Circulation Beneath Mid-Ocean Ridges
Numerical modeling and anMysis are used to investigate the processes leading to the eruption of mantle-derived magma at mid-ocean ridges. Our model includes the following effects: melting due to decompression, magma migration by percolation, and circulation of the mantle driven by both the oceanic plates and the distribution of buoyancy beneath the ridge. The distribution of buoyancy is due to ...
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ژورنال
عنوان ژورنال: Geochemical perspectives letters
سال: 2021
ISSN: ['2410-339X', '2410-3403']
DOI: https://doi.org/10.7185/geochemlet.2103