The age of the martian meteorite Northwest Africa 1195 and the differentiation history of the shergottites

Symes, S; Borg, L; Shearer, C; Irving, A

Title: The age of the martian meteorite Northwest Africa 1195 and the differentiation history of the shergottites

Full Record
Other Related Research

Abstract

Samarium-neodymium isotopic analyses of unleached and acid-leached mineral fractions from the recently identified olivine-bearing shergottite Northwest Africa 1195 yield a crystallization age of 348 {+-} 19 Ma and an {var_epsilon}{sub Nd}{sup 143} value of +40.1 {+-} 1.3. Maskelynite fractions do not lie on the Sm-Nd isochron and appear to contain a martian surface component with low {sup 147}Sm/{sup 144}Nd and {sup 143}Nd/{sup 144}Nd ratios that was added during shock. The Rb-Sr system is disturbed and does not yield an isochron. Terrestrial Sr appears to have affected all of the mineral fractions, although a maximum initial {sup 87}Sr/{sup 86}Sr ratio of 0.701614 {+-} 16 is estimated by passing a 348 Ma reference isochron through the maskelynite fraction that is least affected by contamination. The high initial {var_epsilon}{sub Nd}{sup 143} value and the low initial {sup 87}Sr/{sup 86}Sr ratio, combined with the geologically young crystallization age, indicate that Northwest Africa 1195 is derived from a source region characterized by a long-term incompatible element depletion. The age and initial Sr and Nd isotopic compositions of Northwest Africa 1195 are very similar to those of Queen Alexandra Range 94201, indicating these samples were derived from source regions with nearly identical Sr-Nd isotopic systematics. Thesemore »« less

Authors:: Symes, S; Borg, L; Shearer, C; Irving, A

Publication Date:: Thu Apr 05 00:00:00 EDT 2007

Research Org.:: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

Sponsoring Org.:: USDOE

OSTI Identifier:: 940887

Report Number(s):: UCRL-JRNL-229742
Journal ID: ISSN 0016-7037; GCACAK; TRN: US200824%%383

DOE Contract Number:: W-7405-ENG-48

Resource Type:: Journal Article

Journal Name:: Geochimica et Cosmochimica Acta

Additional Journal Information:: Journal Volume: 72; Journal Issue: 15; Journal ID: ISSN 0016-7037

Country of Publication:: United States

Language:: English

Subject:: 58 GEOSCIENCES; AFRICA; ALGORITHMS; CONTAMINATION; CRYSTALLIZATION; ELEMENTS; METEORITES; RARE EARTHS; TRACE AMOUNTS

Citation Formats


                    Symes, S, Borg, L, Shearer, C, and Irving, A. The age of the martian meteorite Northwest Africa 1195 and the differentiation history of the shergottites.  United States: N. p., 2007. 
        Web.

Copy to clipboard


                    Symes, S, Borg, L, Shearer, C, & Irving, A. The age of the martian meteorite Northwest Africa 1195 and the differentiation history of the shergottites.  United States.

Copy to clipboard


                    Symes, S, Borg, L, Shearer, C, and Irving, A. 2007.  
        "The age of the martian meteorite Northwest Africa 1195 and the differentiation history of the shergottites".  United States.  https://www.osti.gov/servlets/purl/940887.

Copy to clipboard


                    
@article{osti_940887,

  title        = {The age of the martian meteorite Northwest Africa 1195 and the differentiation history of the shergottites},

  author       = {Symes, S and Borg, L and Shearer, C and Irving, A},

  abstractNote = {Samarium-neodymium isotopic analyses of unleached and acid-leached mineral fractions from the recently identified olivine-bearing shergottite Northwest Africa 1195 yield a crystallization age of 348 {+-} 19 Ma and an {var_epsilon}{sub Nd}{sup 143} value of +40.1 {+-} 1.3. Maskelynite fractions do not lie on the Sm-Nd isochron and appear to contain a martian surface component with low {sup 147}Sm/{sup 144}Nd and {sup 143}Nd/{sup 144}Nd ratios that was added during shock. The Rb-Sr system is disturbed and does not yield an isochron. Terrestrial Sr appears to have affected all of the mineral fractions, although a maximum initial {sup 87}Sr/{sup 86}Sr ratio of 0.701614 {+-} 16 is estimated by passing a 348 Ma reference isochron through the maskelynite fraction that is least affected by contamination. The high initial {var_epsilon}{sub Nd}{sup 143} value and the low initial {sup 87}Sr/{sup 86}Sr ratio, combined with the geologically young crystallization age, indicate that Northwest Africa 1195 is derived from a source region characterized by a long-term incompatible element depletion. The age and initial Sr and Nd isotopic compositions of Northwest Africa 1195 are very similar to those of Queen Alexandra Range 94201, indicating these samples were derived from source regions with nearly identical Sr-Nd isotopic systematics. These similarities suggest that these two meteorites share a close petrogenetic relationship and might have been erupted from a common volcano. The meteorites Yamato 980459, Dar al Gani 476, Sayh al Uhaymir 005/008, and Dhofar 019 also have relatively old ages between 474-575 Ma and trace element and/or isotopic systematics that are indicative of derivation from incompatible-element-depleted sources. This suggests that the oldest group of meteorites is more closely related to one another than they are to the younger meteorites that are derived from less incompatible-element-depleted sources. Closed-system fractional crystallization of this suite of meteorites is modeled with the MELTS algorithm using the bulk composition of Yamato 980459 as a parent. These models reproduce many of the major element and mineralogical variations observed in the suite. In addition, the rare-earth element systematics of these meteorites are reproduced by fractional crystallization using the proportions of phases and extents of crystallization that are calculated by MELTS. The combined effects of source composition and fractional crystallization are therefore likely to account for the major element, trace element, and isotopic diversity of all shergottites. Thus, assimilation of a martian crustal component is not required to explain the geochemical diversity of the shergottites.},

  doi          = {},

  url          = {https://www.osti.gov/biblio/940887},
  journal      = {Geochimica et Cosmochimica Acta},

  issn         = {0016-7037},

  number       = 15,

  volume       = 72,

  place        = {United States},

  year         = {Thu Apr 05 00:00:00 EDT 2007},

  month        = {Thu Apr 05 00:00:00 EDT 2007}

}

Copy to clipboard

Journal Article:

View Journal Article (0.77 MB)

Other availability

Find in Google Scholar

Search WorldCat to find libraries that may hold this journal

Save / Share:

Export Metadata

Save to My Library

Similar records in OSTI.GOV collections:

The Northwest Africa 8159 martian meteorite: Expanding the martian sample suite to the early Amazonian

Journal Article Herd, Christopher; Walton, Erin; Agee, Carl; ... - Geochimica et Cosmochimica Acta

Northwest Africa (NWA) 8159 is an augite-rich shergottite, with a mineralogy dominated by Ca-, Fe-rich pyroxene, plagioclase, olivine, and magnetite. NWA 8159 crystallized from an evolved melt of basaltic composition under relatively rapid conditions of cooling, likely in a surface lava flow or shallow sill. Redox conditions experienced by the melt shifted from relatively oxidizing (with respect to known Martian lithologies, ~QFM) on the liquidus to higher oxygen fugacity (~QFM + 2) during crystallization of the groundmass, and under subsolidus conditions. This shift resulted in the production of orthopyroxene and magnetite replacing olivine phenocryst rims. NWA 8159 contains both crystallinemore »« less
Cited by 52
https://doi.org/10.1016/j.gca.2017.08.037

Full Text Available
Accretion timescale and impact history of Mars deduced from the isotopic systematics of martian meteorites

Journal Article Borg, Lars; Brennecka, Gregory; Symes, Steven - Geochimica et Cosmochimica Acta

High precision Sm-Nd isotopic analyses have been completed on a suite of 11 martian basaltic meteorites in order to better constrain the age of silicate differentiation on Mars associated with the formation of their mantle sources. Our data is used to evaluate the merits and disadvantages of various mathematical approaches that have been employed in previous work on this topic. Ages determined from the Sm-Nd isotopic systematics of individual samples are strongly dependent on the assumed Nd isotopic composition of the bulk planet. This assumption is problematic given differences observed between the Nd isotopic composition of Earth and chondritic meteoritesmore »« less
Cited by 58
https://doi.org/10.1016/j.gca.2015.12.002

Full Text Available
Mantle–melt partitioning of the highly siderophile elements: New results and application to Mars

Journal Article Righter, Kevin; Rowland II, Richard; Danielson, Lisa; ... - Meteoritics and Planetary Science

Trace elements and extant and extinct isotopic attributes in Martian meteorites have been used to argue that Mars accreted quickly, differentiated into core and mantle, and established several mantle reservoirs, possibly within 10 Ma of T0. The partitioning of trace elements in the deep mantle has been relatively unstudied, despite the need for such knowledge in understanding magma ocean crystallization and the origin of depleted and enriched mantle reservoirs. The siderophile element composition of the Martian mantle and lithophile isotopic systems such as Sr, Hf, and Nd are thought to record evidence for early metal–silicate equilibrium and deep magma oceanmore »« less
https://doi.org/10.1111/maps.13598

Full Text Available
A combined Sm-Nd, Rb-Sr, and U-Pb isotopic study of Mg-suite norite 78238: Further evidence for early differentiation of the Moon

Journal Article Edmunson, J; E Borg, L; Nyquist, L; ... - Geochimica et Cosmochemica acta, vol. 73, N/A, January 15, 2009, pp. 514-527

Lunar Mg-suite norite 78238 was dated using the Sm-Nd, Rb-Sr, and U-Pb isotopic systems in order to constrain the age of lunar magma ocean solidification and the beginning of Mg-suite magmatism, as well as to provide a direct comparison between the three isotopic systems. The Sm-Nd isotopic system yields a crystallization age for 78238 of 4334 {+-} 37 Ma and an initial {var_epsilon}{sub Nd}{sup 143} value of -0.27 {+-} 0.74. The age-initial {var_epsilon}{sub Nd}{sup 143} (T-I) systematics of a variety of KREEP-rich samples, including 78238 and other Mg-suite rocks, KREEP basalts, and olivine cumulate NWA 773, suggest that lunar differentiationmore »« less
Full Text Available
Sr and Nd isotopic relationships in the Oka carbonatite complex, Canada

Conference Wen, J; Bell, K; Blenkinsop, J - Geol. Soc. Am., Abstr. Programs; (United States)

A detailed isotopic study on separated minerals and whole-rock samples from the Oka complex, which intrudes rocks of Grenville age near Montreal, Quebec, shows that the complex had a very small variation in initial isotopic composition for both Sr and Nd. Apatite, calcite, garnet, melilite, olivine, and pyroxene separates give a range for initial /sup 87/Sr//sup 86/Sr of 0.70323 - 0.70334; and for initial /sup 143/Nd//sup 144/Nd of 0.51281 - 0.51271 (/epsilon//sub Sr/ =-16.2 to -14.2; /epsilon//sub Nd/=6.1 to 4.1). The negative /epsilon//sub Sr/ and positive /epsilon//sub Nd/ values indicate derivation of the Sr and Nd from a source withmore »« less

Similar Records