Imperial College London
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Professor Mark Rehkämper

Faculty of Engineering, Department of Earth Science & Engineering

Professor of Isotope Geochemistry
 
 
 
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Contact

 

markrehk Website

 
 
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Location

 

451Royal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Poole:2017:10.1016/j.epsl.2017.05.001,
author = {Poole, GM and Rehkamper, M and Coles, BJ and Goldberg, T and Smith, CL},
doi = {10.1016/j.epsl.2017.05.001},
journal = {Earth and Planetary Science Letters},
pages = {215--226},
title = {Nucleosynthetic molybdenum isotope anomalies in ironmeteorites – new evidence for thermal processing of solarnebula material},
url = {http://dx.doi.org/10.1016/j.epsl.2017.05.001},
volume = {473},
year = {2017}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - We have investigated nucleosynthetic Mo isotope anomalies in 38 different bulk iron meteorites from 11 groups, to produce by far the largest and most precise dataset available to date for such samples. All magmatic iron groups were found to display deficits in s-process Mo isotopes, with essentially constant anomalies within but significant variations between groups. Only meteorites of the non-magmatic IAB/IIICD complex revealed terrestrial Mo isotopic compositions.The improved analytical precision achieved in this study enables two isotopically distinct suites of iron meteorites to be identified. Of these, the r=p suite encompasses the IC, IIAB, IIE, IIIAB, IIIE and IVA groups and exhibits relatively modest but ‘pure’ s-process deficits, relative to Earth. The second r>p suite includes groups IIC, IIIF and IVB. These iron meteorites show larger s-process deficits than the r=p suite, coupled with an excess of r-process relative to p-process components.Comparison of the results with data for other elements (e.g., Cr, Ni, Ru, Ti, Zr) suggests that the Mo isotope variability is most likely produced by thermal processing and selective destruction of unstable presolar phases. An updated model is proposed, which relates the iron meteorite suites to different extents of thermal processing in the solar nebula, as governed by heliocentric distance. In detail, the r=p suite of iron meteorite parent bodies is inferred to have formed closer to the Sun, where the extent of thermal processing was similar to that experienced by terrestrial material, so that the meteorites exhibit only small s-process deficits relative to Earth. In contrast, the r>p suite formed at greater heliocentric distance, where more subtle thermal processing removed a smaller proportion of r- and p-process host phases, thereby generating larger s-process deficits relative to the terrestrial composition. In addition, the thermal conditions enabled selective destruction of p- versus r-isotope
AU  - Poole,GM
AU  - Rehkamper,M
AU  - Coles,BJ
AU  - Goldberg,T
AU  - Smith,CL
DO  - 10.1016/j.epsl.2017.05.001
EP  - 226
PY  - 2017///
SN  - 1385-013X
SP  - 215
TI  - Nucleosynthetic molybdenum isotope anomalies in ironmeteorites – new evidence for thermal processing of solarnebula material
T2  - Earth and Planetary Science Letters
UR  - http://dx.doi.org/10.1016/j.epsl.2017.05.001
UR  - http://hdl.handle.net/10044/1/48823
VL  - 473
ER  -
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