The solar wind (SW) is the major source of information to study the solar composition of volatile elements. It provides insights about the Sun's present state, its evolution and the composition of the proto-solar nebula. SW noble gases can be used to study processes causing fractionation between the Sun and the SW. Moreover they are useful to determine compositional variations for distinct SW energy regimes including the high energy SEP component apparently abundant in lunar samples [I]. We will present noble gas data collected on Genesis [2] with a bulk  metallic glass target (BMG) [3]

Alton, J. H.

Baur, H.

Bochsler, P.

Burnett, D. S.

Bühler, F.

Grimberg, A.

Hays, C. C.

Heber, V. S.

Jurewicz, A. J. G.

McNamara, K.

Tosatti, S.

Wieler, R.

Caltech Authors - Main

A60 68th Meeting of the Meteoritical Society: Abstracts 
5312 
CHLORINE-RICH APATITES IN SNCs: EVIDENCE FOR MAGMA-
BRINE INTERACTIONS ON MARS? 
J. P. Greenwood. Earth and Environmental Sciences Department, Wesleyan 
University, Middletown, Connecticut 06459, USA. E-mail: 
jgreenwood@wesleyan.edu 
Chlorine-rich apatites are ubiquitous in Martian meteorites. 
Chlorapatite is rare on Earth, as fluorapatite is the dominant phosphate phase 
in terrestrial igneous rocks. Recent work suggests that the chlorapatite of the 
Stillwater and Bushveld Intrusions results from the interactions of magma 
and briny fluids [1]. Due to the partitioning ofF/Cl in magmatic systems, 
there is not a simple mechanism for forming chlorapatites without the 
addition of a Cl-rich component. I propose that all SNCs that contain 
chlorapatite formed from interactions of SNC parent magmas with 
subsurface brines on Mars. If true, one must question our basic assumptions 
regarding Martian geochemistry, as derived from the study of SNC 
meteorites. For example, high D/H in chlorapatites [e.g., 2] may not be 
magmatic values, but a signature of the briny fluid. Theories on the chemical 
composition of the Martian mantle, as derived from the chemical 
composition of SNCs [e.g., 3], need to be re-evaluated in light of the 
interactions of SNC parent magmas with brines. Partitioning studies of trace 
elements between Fe-rich SNC-type magmas and saline fluids are needed to 
properly evaluate the role of brines in Martian magmatic systems. 
References: [1] Mathez E. A. and Webster J. D. 2005. Geochimica et 
Cosmochimica Acta 69:1275-1286. [2] Leshin L. A. 2000. Geophysical 
Research Letters 27:2017-2020. [3] Wanke H. and Dreibus G. 1994. 
Philosophical Transactions of the Royal Society of London A 349:285-293. 
5222 
SOLAR WIND NOBLE GASES-PRELIMINARY RESULTS FROM 
BULK METALLIC GLASS FLOWN ON GENESIS 
A. Grimberg1, F. Buhler2, P. Bochsler2, V. S. Heber1, S. Tosatti3, A. J. G. 
Jurewicz4, C. C. Hays4, K. McNamara5, J. H. Allton5, D. S. Burnett6, 
H. Baur1, and R. Wieler 1• 1Isotope Geology, ETH Zurich, Switzerland. E-
mail: grimberg@erdw.ethz.ch. 2Physikalisches lnstitut, University of Bern, 
Bern, Switzerland. 3Surface Science and Technology, ETH Zurich, 
Switzerland. 4NASA Jet Propulsion Laboratory, Pasadena, California 91109, 
USA. 5NASA Johnson Space Center, Houston, Texas 77058, USA. 6GPS, 
Ca!Tech, Pasadena, California, USA. 
Introduction: The solar wind (SW) is the major source of information 
to study the solar composition of volatile elements. It provides insights about 
the Sun's present state, its evolution and the composition of the proto-solar 
nebula. SW noble gases can be used to study processes causing fractionation 
between the Sun and the SW. Moreover they are useful to determine 
compositional variations for distinct SW energy regimes including the high 
energy SEP component apparently abundant in lunar samples [I]. We will 
present noble gas data collected on Genesis [2] with a bulk metallic glass 
target (BMG) [3]. 
Experiment: The BMG plate was exposed during the entire SW 
collecting period of 884 days. So far, extensive X-ray photo-electron 
spectroscopy (XPS) analyses were carried out on the BMG to determine the 
thickness and composition of surface contamination ubiquitous on Genesis 
targets. For qualitative information XPS energy scans (0-1200 eV) were 
measured on 90 spots (0 = 100 µm). On areas revealing most intense 
contamination signals tilt angle measurements were done to determine the 
thickness. 
Noble gases will be released by pyrolysis of the BMG at about 1300 °C 
and by closed system stepwise etching (CSSE) [4]. This depth resolving 
technique allows us to distinguish noble gases related to the SW from ions 
implanted at higher energies (SEP) and thus implanted to larger depth. 
Results: The XPS data show that contamination is omnipresent on the 
BMG surface. The major contaminant is a polymerized organic layer mainly 
consisting of Si, C, 0, N and minor F. Its signals are highest close to the holes 
used for screws to mount the BMG. This supports the idea that the organic 
layer is related to glue the screws of the BMG were fixed with. However, 
since the BMG element Zr is always visible in the XPS spectra, 
contamination at the measured spots is very unlikely to be thicker than I 0 nm 
(max. depth resolution of XPS used for this study). If the organic layer has 
been deposited homogeneously on the surface, which we expect after 
extensive XPS survey, then this layer would not have influenced the noble 
gas trapping noticeably. Minor elements as Mg stem from soil particles of the 
Utah desert. 
Overall, XPS analyses and microscopic studies indicate that the BMG 
is suitable for precise noble gas analysis. Noble gas results will be discussed 
at the conference. 
References: [I] Wieler R. et al. 1986. Geochimica et Cosmochimica 
Acta 50: 1997-2017. [2] Burnett D. S. et al. 2003. Space Science Reviews 
105:509-534. [3] Jurewicz A. J. G. et al. 2003. Space Science Reviews 105: 
535-560. [4] Heber V. S. et al. 2003. The Astrophysical Journal 597:602-
614. 


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Solar wind noble gases - Preliminary results from bulk metallic glass flown on Genesis

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Solar wind noble gases - Preliminary results from bulk metallic glass flown on Genesis

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