Iron isotope differences between Earth, Moon, Mars and Vesta as possible records of contrasted accretion mechanisms

被引:253
作者
Poitrasson, F
Halliday, AN
Lee, DC
Levasseur, S
Teutsch, N
机构
[1] CNRS, UPS, IRD, Lab Etud Mecanismes Transfert Geol, F-31400 Toulouse, France
[2] ETH Zentrum, Dept Erdwissensch, Inst Isotopengeol, CH-8092 Zurich, Switzerland
[3] Acad Sinica, Inst Earth Sci, Nankang 115, Tapei, Peoples R China
[4] Swiss Fed Inst Environm Sci & Technol, EAWAG, CH-8600 Dubendorf, Switzerland
关键词
iron isotopes; Earth and Moon formation; SNC meteorites; eucrites; diogenites; Mars; Vesta; planetology;
D O I
10.1016/j.epsl.2004.04.032
中图分类号
P3 [地球物理学]; P59 [地球化学];
学科分类号
0708 ; 070902 ;
摘要
The iron isotope compositions of Shergotty-Nakhla-Chassigny (SNC) meteorites thought to come from Mars, eucrites and diogenites assumed to sample asteroid 4 Vesta, and rocks from the Moon and Earth have been measured using high precision plasma source mass spectrometry. The means of eight samples from Mars and nine samples from Vesta are within error identical despite a range of rock types. They are lighter by similar to 0.1parts per thousand in delta(57)Fe/Fe-54 compared to the average of 13 terrestrial mantle-derived rocks. The latter value is identical within uncertainty with a previously published mean of 46 igneous rocks from the Earth. The average for 14 lunar basalts and highland plutonic rocks covering a broad spectrum of major element composition is heavier by similar to 0.1parts per thousand in delta(57)Fe/Fe-54 relative to our estimate for the Earth's mantle, and therefore similar to 0.2parts per thousand heavier than the eucrites, diogenites and SNC meteorites. However, the data scatter somewhat and the Apollo 15 green glass and Apollo 17 orange glass are identical to samples from Mars and Vesta. There is no clear relationship between petrological characteristics and Fe isotope composition despite a wide spectrum of samples. Instead, contrasted planetary isotopic signatures are clearly resolved statistically. After evaluating alternative scenario, it appears that the most plausible explanation for the heavier Fe in the Earth and Moon is that both objects grew via processes that involved partial vaporisation leading to kinetic iron isotope fractionation followed by minor loss. This is consistent with the theory in which the Moon is thought to have originated from a giant impact between the proto-Earth and another planet. Combined with numerical simulations, Fe isotope data can offer the potential to provide constraints on the processes that occurred in planetary accretion. (C) 2004 Elsevier B.V. All rights reserved.
引用
收藏
页码:253 / 266
页数:14
相关论文
共 61 条
[1]   Chemical composition of the Earth and the volatility control on planetary genetics [J].
Allègre, C ;
Manhès, G ;
Lewin, É .
EARTH AND PLANETARY SCIENCE LETTERS, 2001, 185 (1-2) :49-69
[2]  
[Anonymous], ORIGIN EARTH
[3]  
[Anonymous], 2000, ORIGIN EARTH MOON
[4]   FORMATION OF APOLLO-15 GREEN GLASS-BEADS [J].
ARNDT, J ;
VONENGELHARDT, W ;
GONZALEZCABEZA, I ;
MEIER, B .
JOURNAL OF GEOPHYSICAL RESEARCH, 1984, 89 :C225-C232
[5]   High precision iron isotope measurements of terrestrial and lunar materials [J].
Beard, BL ;
Johnson, CM .
GEOCHIMICA ET COSMOCHIMICA ACTA, 1999, 63 (11-12) :1653-1660
[6]   Application of Fe isotopes to tracing the geochemical and biological cycling of Fe [J].
Beard, BL ;
Johnson, CM ;
Skulan, JL ;
Nealson, KH ;
Cox, L ;
Sun, H .
CHEMICAL GEOLOGY, 2003, 195 (1-4) :87-117
[7]   High precision measurement of iron isotopes by plasma source mass spectrometry [J].
Belshaw, NS ;
Zhu, XK ;
Guo, Y ;
O'Nions, RK .
INTERNATIONAL JOURNAL OF MASS SPECTROMETRY, 2000, 197 :191-195
[8]   CONTRASTING RE OS MAGMATIC FRACTIONATION IN PLANETARY BASALTS [J].
BIRCK, JL ;
ALLEGRE, CJ .
EARTH AND PLANETARY SCIENCE LETTERS, 1994, 124 (1-4) :139-148
[9]  
Cameron AGW, 2000, Origin of the Earth and Moon, P133
[10]   Origin of the Moon in a giant impact near the end of the Earth's formation [J].
Canup, RM ;
Asphaug, E .
NATURE, 2001, 412 (6848) :708-712