Details
| Original language | English |
|---|---|
| Pages (from-to) | 6-18 |
| Number of pages | 13 |
| Journal | Earth and Planetary Science Letters |
| Volume | 245 |
| Issue number | 1-2 |
| Publication status | Published - 15 May 2006 |
| Externally published | Yes |
Abstract
Lithium isotope compositions and concentrations of 12 lunar samples (including two high-Ti, three low-Ti mare basalts, five highland breccias, one orange and one green glass) and 7 Martian meteorites (three basaltic and one lherzolitic shergottite, two nakhlites, and the orthopyroxenite ALHA 84001 were measured using MC-ICP-MS. Most of the Martian samples have a narrow range of δ7Li (+ 3.6 to + 5.2‰). Only ALHA 84001 is isotopically lighter, with δ7Li = - 0.6‰. The range in Li concentrations is limited and all shergottites have identical Li concentrations (1.8-2.1 μg/g) and isotope compositions within the error. Despite a larger variation in Li concentrations (5-49 μg/g), Li isotope variation of most lunar samples is also very limited (+ 3.5 to + 6.6‰) with an average of + 5.2‰ (± 1.2, 2σ). The only exception is one KREEP-rich highland breccia (15445a), which has a δ7Li value of + 18.6‰. Consequently, the majority of lunar and Martian samples have an isotopic signature similar to the Earth's mantle (MORB and OIB). These results imply a homogeneous Li isotope composition of the inner solar system with a δ7Li ≈ + 4‰. The results further indicate that planetary silicate differentiation by partial melting on planets under either wet or dry conditions does not significantly fractionate Li isotope compositions. Lithium abundances of lunar basalts and glasses are similar to those of terrestrial basalts. In contrast, Martian basalts have generally lower Li concentrations, more similar to BSE, although the concentrations in shergottitic clinopyroxenes and nakhlitic pyroxenites do not indicate a lower Li abundance for bulk Mars. These systematics imply that the Martian basalts were depleted in Li by a process that did not fractionate the Li isotope composition.
Keywords
- KREEP, lithium isotopes, mare basalts, Mars, moon, SNC meteorites
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geophysics
- Earth and Planetary Sciences(all)
- Geochemistry and Petrology
- Earth and Planetary Sciences(all)
- Earth and Planetary Sciences (miscellaneous)
- Earth and Planetary Sciences(all)
- Space and Planetary Science
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In: Earth and Planetary Science Letters, Vol. 245, No. 1-2, 15.05.2006, p. 6-18.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Lithium isotope compositions of Martian and lunar reservoirs
AU - Seitz, Hans Michael
AU - Brey, Gerhard P.
AU - Weyer, Stefan
AU - Durali, Soodabeh
AU - Ott, Ulrich
AU - Münker, Carsten
AU - Mezger, Klaus
N1 - Funding information: This study was financially supported by the Deutsche Forschungsgemeinschaft (Grant No. BR 1012/19-1). We profited much from discussions with Dmitri Ionov, Frank Brenker, Yann Lahaye, Jutta Zipfel, Andrew Berry and Margaret Hanrahan. For technical assistance we thank Anna Karina Neumann, Thomas Kautz, and Franz Kneissl. Vincent Courtillot (editorial handling), Roberta Rudnick, Tim Elliott and an anonymous reviewer are thanked for their constructive reviews.
PY - 2006/5/15
Y1 - 2006/5/15
N2 - Lithium isotope compositions and concentrations of 12 lunar samples (including two high-Ti, three low-Ti mare basalts, five highland breccias, one orange and one green glass) and 7 Martian meteorites (three basaltic and one lherzolitic shergottite, two nakhlites, and the orthopyroxenite ALHA 84001 were measured using MC-ICP-MS. Most of the Martian samples have a narrow range of δ7Li (+ 3.6 to + 5.2‰). Only ALHA 84001 is isotopically lighter, with δ7Li = - 0.6‰. The range in Li concentrations is limited and all shergottites have identical Li concentrations (1.8-2.1 μg/g) and isotope compositions within the error. Despite a larger variation in Li concentrations (5-49 μg/g), Li isotope variation of most lunar samples is also very limited (+ 3.5 to + 6.6‰) with an average of + 5.2‰ (± 1.2, 2σ). The only exception is one KREEP-rich highland breccia (15445a), which has a δ7Li value of + 18.6‰. Consequently, the majority of lunar and Martian samples have an isotopic signature similar to the Earth's mantle (MORB and OIB). These results imply a homogeneous Li isotope composition of the inner solar system with a δ7Li ≈ + 4‰. The results further indicate that planetary silicate differentiation by partial melting on planets under either wet or dry conditions does not significantly fractionate Li isotope compositions. Lithium abundances of lunar basalts and glasses are similar to those of terrestrial basalts. In contrast, Martian basalts have generally lower Li concentrations, more similar to BSE, although the concentrations in shergottitic clinopyroxenes and nakhlitic pyroxenites do not indicate a lower Li abundance for bulk Mars. These systematics imply that the Martian basalts were depleted in Li by a process that did not fractionate the Li isotope composition.
AB - Lithium isotope compositions and concentrations of 12 lunar samples (including two high-Ti, three low-Ti mare basalts, five highland breccias, one orange and one green glass) and 7 Martian meteorites (three basaltic and one lherzolitic shergottite, two nakhlites, and the orthopyroxenite ALHA 84001 were measured using MC-ICP-MS. Most of the Martian samples have a narrow range of δ7Li (+ 3.6 to + 5.2‰). Only ALHA 84001 is isotopically lighter, with δ7Li = - 0.6‰. The range in Li concentrations is limited and all shergottites have identical Li concentrations (1.8-2.1 μg/g) and isotope compositions within the error. Despite a larger variation in Li concentrations (5-49 μg/g), Li isotope variation of most lunar samples is also very limited (+ 3.5 to + 6.6‰) with an average of + 5.2‰ (± 1.2, 2σ). The only exception is one KREEP-rich highland breccia (15445a), which has a δ7Li value of + 18.6‰. Consequently, the majority of lunar and Martian samples have an isotopic signature similar to the Earth's mantle (MORB and OIB). These results imply a homogeneous Li isotope composition of the inner solar system with a δ7Li ≈ + 4‰. The results further indicate that planetary silicate differentiation by partial melting on planets under either wet or dry conditions does not significantly fractionate Li isotope compositions. Lithium abundances of lunar basalts and glasses are similar to those of terrestrial basalts. In contrast, Martian basalts have generally lower Li concentrations, more similar to BSE, although the concentrations in shergottitic clinopyroxenes and nakhlitic pyroxenites do not indicate a lower Li abundance for bulk Mars. These systematics imply that the Martian basalts were depleted in Li by a process that did not fractionate the Li isotope composition.
KW - KREEP
KW - lithium isotopes
KW - mare basalts
KW - Mars
KW - moon
KW - SNC meteorites
UR - http://www.scopus.com/inward/record.url?scp=33646166087&partnerID=8YFLogxK
U2 - 10.1016/j.epsl.2006.03.007
DO - 10.1016/j.epsl.2006.03.007
M3 - Article
AN - SCOPUS:33646166087
VL - 245
SP - 6
EP - 18
JO - Earth and Planetary Science Letters
JF - Earth and Planetary Science Letters
SN - 0012-821X
IS - 1-2
ER -