Revisiting the Wasson fractional crystallization model for IIIAB iron meteorites with implications for the interpretation of their Fe isotope ratios

2021 ◽  
Author(s):  
Edward D. Young ◽  
Edward Scott
Keyword(s):  
Fractional Crystallization ◽  
Isotope Ratios ◽  
Iron Meteorites

scholarly journals Determinations of osmium isotope ratios in iron meteorites and iridosmines by ICP-MS.

1986 ◽  
Vol 20 (5) ◽  
pp. 233-239 ◽  
Author(s):  
Akimasa Masuda ◽  
Takafumi Hirata ◽  
Hiroshi Shimizu
Keyword(s):  
Isotope Ratios ◽  
Iron Meteorites ◽  
Icp Ms ◽  
Osmium Isotope

Oxygen Isotope Ratios in the Crust of Iron Meteorites

1971 ◽  
Vol 26 (9) ◽  
pp. 1485-1490 ◽  
Author(s):  
K. Heinzinger ◽  
C. Iunge ◽  
M. Schidlowski
Keyword(s):  
Oxygen Isotope ◽  
Isotope Ratio ◽  
Atmospheric Oxygen ◽  
Isotope Ratios ◽  
Oxygen Isotope Ratio ◽  
Iron Meteorites ◽  
Oxygen Isotope Ratios ◽  
Cosmic Spherules ◽  
The Difference ◽  
Extraterrestrial Material

Abstract The separation factor, aM-0= (18O/16O) magnetite/' (18O/16O) atmospheric oxygen, between the magnetite crust of iron meteorites and atmospheric oxygen has been determined to be 0.9946 ± 0.0005. It is concluded that this fractionation of the oxygen isotopes is the consequence of an equilibrium isotope effect at high temperatures. It can be assumed that this is also valid for cosmic spherules, which are mainly ablation products of iron meteorites. As these spherules are found in sediments of different geological ages, their oxygen isotope ratio can give information on the development of atmospheric oxygen. The difference of the oxygen isotope ratios between magnetite from the lithosphere and airborne magnetite can be used to distinguish between terrestrial and extraterrestrial material.

Origin of anomalous iron meteorites

1979 ◽  
Vol 43 (327) ◽  
pp. 415-421 ◽  
Author(s):  
Edward R. D. Scott
Keyword(s):  
Fractional Crystallization ◽  
Genetic Relationships ◽  
Bulk Composition ◽  
Iron Meteorites ◽  
End Members ◽  
Chemical Groups ◽  
Chemical Trends

SummaryAnomalous iron meteorites are those which do not have Ni, Ga, and Ge contents appropriate to one of the twelve chemical groups; they account for 14% of all irons. The chemistry of irons in the twelve groups can be largely understood in terms of primary fractionation in the nebula, which established the bulk composition of the groups, and secondary fractionation in the parent bodies (probably fractional crystallization), which produced the chemical trends within groups. Logarithmic element-Ga graphs containing data for groups and anomalous irons reveal that anomalous irons experienced the same primary and secondary fractionations as affected the groups.The uniformity of chemical trends within groups allows possible genetic relationships between anomalous irons and groups and among anomalous irons to be tested. It is concluded that the sixty-nine anomalous irons are samples from fifty-odd additional groups, which had similar histories to the twelve groups. Less than five of the anomalous irons could be compositional end- members or reprocessed irons from the groups.Because ‘anomalous’ means abnormal, some other term for the irons which do not belong to the twelve groups would be a useful reminder that these irons formed in a similar way to irons in the major groups. They could be called members of minor groups or grouplets.

Modeling fractional crystallization of group IVB iron meteorites

2008 ◽  
Vol 72 (8) ◽  
pp. 2198-2216 ◽  
Author(s):  
Richard J. Walker ◽  
William F. McDonough ◽  
Jenise Honesto ◽  
Nancy L. Chabot ◽  
Timothy J. McCoy ◽  
...  
Keyword(s):  
Fractional Crystallization ◽  
Iron Meteorites

scholarly journals Generation of the Mt Kinabalu Granite by Crustal Contamination of Intraplate Magma Modelled by Equilibrated Major Element Assimilation with Fractional Crystallization (EME-AFC)

2019 ◽  
Vol 60 (7) ◽  
pp. 1461-1487 ◽  
Author(s):  
A Burton-Johnson ◽  
C G Macpherson ◽  
C J Ottley ◽  
G M Nowell ◽  
A J Boyce
Keyword(s):  
Oxygen Isotope ◽  
Fractional Crystallization ◽  
Major Element ◽  
Crustal Contamination ◽  
Mafic Magma ◽  
Isotope Ratios ◽  
Geochemical Data ◽  
Magmatic Differentiation ◽  
Clear Trend ◽  
Mount Kinabalu

AbstractNew geochemical data are presented for the composite units of the Mount Kinabalu granitoid intrusion of Borneo and utilised to explore the discrimination between crustal- and mantle-derived granitic magmas. The geochemical data demonstrate that the units making up this composite intrusion became more potassic through time. This was accompanied by an evolution of isotope ratios from a continental-affinity towards a slightly more mantle-affinity (87Sr/86Sri ∼0·7078; 143Nd/144Ndi ∼0·51245; 206Pb/204Pbi ∼18·756 for the oldest unit compared to 87Sr/86Sri ∼0·7065, 143Nd/144Ndi ∼0·51250 and 206Pb/204Pbi ∼18·721 for the younger units). Oxygen isotope ratios (calculated whole-rock δ18O of +6·5–9·3‰) do not show a clear trend with time. The isotopic data indicate that the magma cannot result only from fractional crystallization of a mantle-derived magma. Alkali metal compositions show that crustal anatexis is also an unsuitable process for genesis of the intrusion. The data indicate that the high-K units were generated by fractional crystallization of a primary, mafic magma, followed by assimilation of the partially melted sedimentary overburden. We present a new, Equilibrated Major Element -Assimilation with Fractional Crystallization (EME-AFC) approach for simultaneously modelling the major element, trace element, and radiogenic and oxygen isotope compositions during such magmatic differentiation; addressing the lack of current AFC modelling approaches for felsic, amphibole- or biotite-bearing systems. We propose that Mt Kinabalu was generated through low degree melting of upwelling fertile metasomatized mantle driven by regional crustal extension in the Late Miocene.

Electron Microscope Observations of Mechanical Metamorphism in Iron Meteorites

1970 ◽  
Vol 28 ◽  
pp. 488-489
Author(s):  
D. Faulkner ◽  
G.W. Lorimer ◽  
H.J. Axon
Keyword(s):  
Electron Microscope ◽  
Defect Structure ◽  
Shock Loading ◽  
List Type ◽  
Iron Meteorites

It is now generally accepted that meteorites are fragments produced by the collision of parent bodies of asteroidal dimensions. Optical metallographic evidence suggests that there exists a group of iron meteorites which exhibit structures similar to those observed in explosively shock loaded iron. It seems likely that shock loading of meteorites could be produced by preterrestrial impact of their parent bodies as mentioned above.We have therefore looked at the defect structure of one of these meteorites (Trenton) and compared the results with those made on a) an unshocked ‘standard’ meteorite (Canyon Diablo)b) an artificially shocked ‘standard’ meteorite (Canyon Diablo) andc) an artificially shocked specimen of pure α-iron.

Evidence for ordered Fe3Ni

1987 ◽  
Vol 45 ◽  
pp. 216-217
Author(s):  
K.B. Reuter ◽  
D.B. Williams ◽  
J.I. Goldstein
Keyword(s):  
Experimental Data ◽  
Martensitic Transformation ◽  
Electron Diffraction ◽  
Room Temperature ◽  
Direct Evidence ◽  
Transformation Product ◽  
Iron Meteorites ◽  
X Ray ◽  
Ni Content ◽  
Temperature Transformation

In the Fe-Ni system, although ordered FeNi and ordered Ni3Fe are experimentally well established, direct evidence for ordered Fe3Ni is unconvincing. Little experimental data for Fe3Ni exists because diffusion is sluggish at temperatures below 400°C and because alloys containing less than 29 wt% Ni undergo a martensitic transformation at room temperature. Fe-Ni phases in iron meteorites were examined in this study because iron meteorites have cooled at slow rates of about 10°C/106 years, allowing phase transformations below 400°C to occur. One low temperature transformation product, called clear taenite 2 (CT2), was of particular interest because it contains less than 30 wtZ Ni and is not martensitic. Because CT2 is only a few microns in size, the structure and Ni content were determined through electron diffraction and x-ray microanalysis. A Philips EM400T operated at 120 kV, equipped with a Tracor Northern 2000 multichannel analyzer, was used.

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