Meteorite from Mars

 

        DaG 876 - Martain Meteorite: Shergottite

Martian Meteorite,  Shergottite, 1 piece of  6.216g was found 7th of May 1998 in the desert of AL Jufrah, Central Sahara.

The pyrrhotite of the DaG 876 shergottite has up to 2.5 wt% Ni

This basaltic shergottite belongs to the Olivine-orthopyroxene-phyric Group:

The Mars Rover Spirit found in 2004 on one of its exploration raids on the Red Planets surface in several rocks (called Mazatzal, Humphrey and Adirondack) material  composed of olivine, pigeonite and plagioclase in a way that looks almost identical to DaG 876

Studies of the thermal history of this rock (e.g. rapid cooling rate of the melt) suggests that this material originates from an extruded lava flow near the Martians surface.

Microprobe minerals results:

Olivine FA37-38

Pigeonite En59-66Wo8-14

Augite En52-45Wo33-37

Maskelynite An56-74Or0.2-1.2

Chromite (Fe0.83Mg0.17)(Cr0.85Al0.13Fe0..01Ti0.01)2O4

Ti-Cr-spinel (Fe0.77-0.84Mg0.23-0.16)

(Cr0.49-0.15Fe0.18-0.45Ti0,18-0.30 Al0.14-0.07)2O4

Ilmenite (Fe0.80Mg0.18Cr0.02Mn0.01)TiO3

Pyrrhotite Fe0.8S

The Ti-Cr-spinels showing the complete range from Ti-chromite to Ti-magnetite with 13 to 21 % TiO2 (fig.

1). Ilmenite with about 2.5 % MgO is accompanying these spinels. The observed pyrrhotite bears 0.5 to 2.5% Ni.

Petrological data and mineral-chemistry of Dar al Gani 876 meet those of the four former published olivine-shergottites, discovered in the Upper Sarir al Qattusa between 1996 and 2000 within an area of approximately 30 x 5 km [1, 2, 3, 4], so DaG876 is probably paired with them:

Petrological very similar are also the olivine-shergottite finds of Sayh al Uhaymir 005, 008, 051 and

094 [4, 5] about 4200 km east, in Oman. It was discussed, whether they are also paired with the DaG she-

gottite finds.

Classification: R. BARTOSCHEWITZ1

and D. ACKERMAND2, 1 BML, Lehmweg 53, D-38518 Gifhorn, Germany (Bartoschewitz.Meteorite-Lab@t-

online.de), 2 Inst. für Geowissenschaften der Univ., Olshausenstr. 40,D-24098 Kiel, Germany

Meteoritical Society Meeting (2001) 5055.pdf

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