| 46677 |
Creator |
1c5c32b11b5ad1bd9c846a77784abc38 |
| 46677 |
Creator |
ext-5c7b33ae91d178fbe772ce9ceb4b6e54 |
| 46677 |
Creator |
ext-69c2ec406d9965038788f1848306fe94 |
| 46677 |
Creator |
ext-7b9e300e3af9f02733cfd04fc383a578 |
| 46677 |
Date |
2016-09-01 |
| 46677 |
Is Part Of |
p0012821X |
| 46677 |
Is Part Of |
repository |
| 46677 |
abstract |
Iron is the most abundant multivalent element in planetary reservoirs, meaning its
isotope composition (expressed as δ<sup>57</sup>Fe) may record signatures of processes
that occurred during the formation and subsequent differentiation of the terrestrial
planets. Chondritic meteorites, putative constituents of the planets and remnants
of undifferentiated inner solar system bodies, have δ<sup>57</sup>Fe ≈ 0‰; an isotopic
signature shared with the Martian Shergottite–Nakhlite–Chassignite (SNC) suite of
meteorites. The silicate Earth and Moon, as represented by basaltic rocks, are distinctly
heavier, δ<sup>57</sup>Fe≈+0.1‰. However, some authors have recently argued, on the
basis of iron isotope measurements of abyssal peridotites, that the composition of
the Earth’s mantle is δ<sup>57</sup>Fe = +0.04 ± 0.04‰, indistinguishable from the
mean Martian value. To provide a more robust estimate for Mars, we present new high-precision
iron isotope data on 17 SNC meteorites and 5 mineral separates. We find that the iron
isotope compositions of Martian meteorites reflect igneous processes, with nakhlites
and evolved shergottites displaying heavier δ<sup>57</sup>Fe(+0.05 ± 0.03‰), whereas
MgO-rich rocks are lighter (δ<sup>57</sup>Fe≈−0.01 ±0.02‰). These systematics are
controlled by the fractionation of olivine and pyroxene, attested to by the lighter
isotope composition of pyroxene compared to whole rock nakhlites. Extrapolation of
the δ<sup>57</sup>Fe SNC liquid line of descent to a putative Martian mantle yields
a δ<sup>57</sup>Fe value lighter than its terrestrial counterpart, but indistinguishable
from chondrites. Iron isotopes in planetary basalts of the inner solar system correlate
positively with Fe/Mn and silicon isotopes. While Mars and IV-Vesta are undepleted
in iron and accordingly have chondritic δ<sup>57</sup>Fe, the Earth experienced volatile
depletion at low (1300 K) temperatures, likely at an early stage in the solar nebula,
whereas additional post-nebular Fe loss is possible for the Moon and angrites. |
| 46677 |
authorList |
authors |
| 46677 |
status |
peerReviewed |
| 46677 |
uri |
http://data.open.ac.uk/oro/document/461511 |
| 46677 |
uri |
http://data.open.ac.uk/oro/document/461512 |
| 46677 |
uri |
http://data.open.ac.uk/oro/document/461513 |
| 46677 |
uri |
http://data.open.ac.uk/oro/document/461514 |
| 46677 |
uri |
http://data.open.ac.uk/oro/document/461515 |
| 46677 |
uri |
http://data.open.ac.uk/oro/document/461516 |
| 46677 |
uri |
http://data.open.ac.uk/oro/document/462419 |
| 46677 |
volume |
449 |
| 46677 |
type |
AcademicArticle |
| 46677 |
type |
Article |
| 46677 |
label |
Sossi, Paolo A.; Nebel, Oliver; Anand, Mahesh and Poitrasson, Franck (2016).
On the iron isotope composition of Mars and volatile depletion in the terrestrial
planets. Earth and Planetary Science Letters, 449 pp. 360–371. |
| 46677 |
label |
Sossi, Paolo A.; Nebel, Oliver; Anand, Mahesh and Poitrasson, Franck (2016). On
the iron isotope composition of Mars and volatile depletion in the terrestrial planets.
Earth and Planetary Science Letters, 449 pp. 360–371. |
| 46677 |
Title |
On the iron isotope composition of Mars and volatile depletion in the terrestrial
planets |
| 46677 |
in dataset |
oro |