ElArouss

Caillou Noir
Meteorite Hunter, Direct source from field contact us

EL AROUSS
( Provisionnal Working Name)

Discovery: Caillou Noir 's team, in 3 field prospections in May 2002, February 2003 and December 2003 found 10 meteorites individuals in a place called El Arouss (Sahara) by natives. The bigger weights 4834 g. the smaller weights 62 g, TKW: 15,441 g. Slices, endcuts and cut individuals are proposed by CAILLOU NOIR at: El Arouss for sale

Macroscopic aspect: These meteorites present a rough surface with some holes such as in the 3657 g individual. The sun exposed side is black, while the ground buried side has a rusty colour. But the alterartion stopped at the surface as shows the "crust"/ inside detail. photo 4. No crust is visible with naked eye, with a microscope one can distingish from place to place black bubbly areas: these could be remains of fusion crust. Rough surface correspond to harder metal specks protruding across the surface of the stones.

El Arouss - 3657 g individual.		El Arouss 4834 g individual, with 3 slices cut off.

photo 1	photo 2	photo 3	photo 4

El Arouss 4208 g individual

The oblong individual.	A trained eye can distinguish melt pockets even from the outside	After cutting 12 slices.	Typical thin slice 144 g dimensions: 121905 mm

Microscopic aspect: The first observation of any section of these meteoriues is that it is in remarquable state of conservation: Probably it's one of the best-preserved IMB chondrites available, as nice as Cat Mountain. . Two major lithologies are present in this meteorite. A highly shocked chondritic lithology and an impact melt lithology. Vesicluated cavities are also present, a rare feature in chondritic meteorites.

Chondritic Lithology	Impact Melt Lithology

A nice highly shocked chondritic material with incredible metal veins, light grey chondrules together with yellowish light brown chondrules relicts. Dark spots are vesicules.	A truely totally melt material in large clasts up to 3 cm wide.. Here the metal has flewn and concentrated in thin metallic veins. Only some individuals of this meteorite are brecciated, showing the large impact molten pockets even impact melt veins ( as above) in the L5 S6 matrix. Dark spots are vesicules.

	Light brown chondrule relict	Clear chondrule relict.

MEB photo. Courtesy UBP.	chondrule is 6 mm * 3.5 mm	chondrule is 8 mm *5 mm

From chondritic lithology to highly shocked impact melt, all stages are presents in El Arouss and often in the same individual, this meteorite is of interest because it's one of the best-preserved L - IMB chondrites available. What makes it spectacular is that in most case, metal flows are visible within the melted part surrounding the partially melted islands.

Analyses: Specimens have been send to several European laboratories.

Some hollow cavities across the meteorite. ( in dark black on the 2 lithologies photo). Scientists call them vesicules. An hypothesis to explain their formation is given by VESICULATION IN ORDINARY CHONDRITES DUE TO IMPACT MELTING: THE “PAT” 91501 ANSWERS

Abstract: Vesicular meteorites are rare among the world’s collections. While there is some small amount of H2O in bulk L chondrite [7], the association of the metal/sulfide assemblages with large vesicles is intriguing and leads us to the hypothesis that the gas that formed the vesicles is SO2 formed by vaporization of the FeS during melting of Fe,Ni metal and sulfide.
in VESICULATION IN ORDINARY CHONDRITES DUE TO IMPACT MELTING: THE “PAT” 91501 ANSWERS.G.K. Benedix1,2, R.A. Ketcham3, T.J. McCoy1, and L. Wilson4. 1Dept. of Mineral Sciences, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560-0119 USA, 2Present Address: Wash-ington University, Dept. of Earth and Planetary Sciences, Saint Louis, MO 63130 USA (gbenedix@levee.wustl.edu), 3Dept. of Geological Sciences, Univ. of Texas at Austin, Austin, TX 78712 USA, 4Environmental Sci. Dept., Inst. of Environmental and Biological Sci., Lancaster Univ., Lancaster LA1 4YQ UK

Ref: [1] McCoy T.J. et al., (2002) LPS XXXIII Abstract #1213. [2] Taylor G.J. et al. (1979) GCA, 43, 323-337. [3] Kring D.A. et al., (1996) JGR, 101, 29,353-29,371. [4] Score R. and Lindstrom M.M. (1992) Ant. Meteorite News. 35, #2. [5] Harvey R.P. (1993) Meteoritics 28,360. [6] Mittlefehldt D.W and Lindstrom M.M. (2001) Meteoritics and Planet. Sci. 36, 439-457. [7] Jarosewich, E. (1990) Meteoritics 25, 323-337. [8] Rubin A.E. (2002) GCA, 66, 699-711. [9] McSween H.Y. et al. (1991) Icarus 91, 107-116. Figure 1. 3-dimensional image of PAT 91501,50 from CT scans showing the distribution of vesicles (green) and metal (purple)/sulfide(orange) blebs. The long dimension is approximately 15cm. Some of the larger vesicles are greater than 1 cm in diameter. Lunar and Planetary Science XXXIV (2003)1947.pdf