Shergottites
Name
*click on the Name for more information
Structure Class
achondrites
Chemical Class
Martian (shergottite)
Country
Year found
1998
Mass
2.02 kg
[Museum Collection]
(1) 21.8g


A brownish stone weighing 2015 g was found in Dar al Gani, Sahara. Mineralogy and classification (J. Zipfel and P. Scherer, MPI): fusion crust absent; meteorite has a porphyritic texture, consisting of olivine embedded in a fine-grained matrix of clinopyroxene laths (pigeonite and minor augite) and interstitial feldspathic glass; mineral abundances similar to EET 79001 lithology A; Fe-sulfide, Ti-rich chromites, ilmenite and chromite present; shock features include twinning and fracturing of clinopyroxene, mosaicism of some olivine, and plagioclase converted to feldspathic glass; impact-melt pockets abundant; extensive terrestrial weathering resulted in carbonate veins crosscutting the meteorite along grain boundaries and cracks; bulk chemistry intermediate between basaltic and lherzolitic shergottites, with a high bulk Mg/(Mg + Fe), high concentrations of siderophile elements, relatively low abundances of heavy rare earth elements (HREE), and a strong light rare earth element (LREE) depletion; exposure age 1.1 ± 0.2 Ma; 36Ar/132Xe and 84Kr/132Xe typical of Martian meteorites, and 129Xe/132Xe similar to Chassigny. Oxygen isotopes (I. Franchi, OU): d18O = 4.57, d17O = 2.69‰ rel. SMOW (D17O = 0.317). The petrography, mineralogy, and noble gas chemistry of DaG 476 and DaG 489 are very similar, and the two are likely paired (L. Folco, MNA-SI, and J. Zipfel and L. Schultz, MPI). Specimens: type specimen, several grams, and one polished section, MPI; main mass with anonymous finder.
Name
*click on the Name for more information
Structure Class
achondrites
Chemical Class
Martian (shergottite)
Country
Year found
1999
Mass
1344 g
[Museum Collection]
(1) 15.1g (2) 5.892g



At two locations, 1864 m apart, five grey-greenish stones were found that are macroscopically identical. Sayh al Uhaymir (SaU) 005 comprises one fragment of 547 g and two individuals of 561 and 236 g, which are partially covered by fusion crust and show regmaglyptes. Sayh al Uhaymir 008 comprises one large individual of 7805 g and a smaller fragmented individual of 774 g. On the latter, the fresh black fusion crust is almost completely preserved. The total mass of SaU 005/008 is 9923 g. Mineralogy and classification (J. Zipfel, MPI): porphyritic texture with large olivine phenocrysts (Fo64–71) in a fine-grained groundmass of pigeonite (En61–70Wo6–13) and maskelynite (An51–65Or0.3–0.9); minor phases are augite, phosphates, and opaques; strongly shocked: mosaicism and planar deformation of olivines, twinning and fracturing of clinopyroxene, and up to millimeter-sized shock melted areas with quench textures are common; brown-orange ringlike structures formed by extremely fine-grained intergrowths of unidentified phases are abundant in impact-melt areas and pyroxenes; the meteorite is extremely fresh, with only a few of the larger cracks partially filled with calcite. Bulk chemical analyses (B. Spettel, G. Dreibus, MPI; H. Palme, Köln), noble gas analyses (M. Paetsch, L. Schultz, MPI), and Sm-Nd systematics (E. Jagoutz, MPI): texture, bulk chemistry, noble gases, and Sm-Nd systematics indicate a very close relationship to Dar al Gani 476/489/670/735; however, on the basis of the distinct mineral chemistry and the place of find, simple pairing with those meteorites can be excluded. Specimens: type specimen, 60 g, MPI; main mass with anonymous finder.
Name
*click on the Name for more information
Structure Class
achondrites
Chemical Class
Martian (shergottite)
Country
Year found
2022
Mass
6.9 kg
[Museum Collection]
(1) 103g


History: Mark Lyon and Robert Ward purchased this meteorite from Aziz Habibi in 2022. This meteorite was found approximately 90 km east of the Wafa Oil Field and 100 km south of the geyser hot springs at Wadi Harakat. Physical characteristics: Single stone, exterior with patches of dark fusion crust and patches of brown-green from weathering and exposed interior minerology. Saw-cut surfaces reveal light colored domains of pyroxene poikilitically enclosing smaller darker olivines, and are bounded by groundmass darker olivine dominated zones. Petrography: (C. Agee and A. Ross, UNM) Reflected light microscopy and electron microprobe analysis show this meteorite to be a plagioclase (maskelynite) lherzolite with a poikilitic texture. Major phases are pigeonite, augite, olivine, and maskelynite. Minor phases include chromite, Cr-Ti spinel, ilmenite, and troilite. Geochemistry: (A. Ross, UNM) Olivine Fa30.9±0.9, Fe/Mn=54±3, n=5; pigeonite Fs23.0±2.7Wo5.3±2.9, Fe/Mn=30±3, n=7; augite Fs14.8±0.2Wo34.9±0.6, Fe/Mn=24±2, n=3; maskelynite An48.7±5.3Ab49.4±4.9Or1.8±0.4, n=4. Classification: Martian lherzolitic shergottite (aka poikilitic shergottite). The poikilitic texture of this meteorite strongly resembles NWA 1950. Specimens: 21.6 g on deposit at UNM, Mark Lyon and Robert Ward hold the main mass.
Name
*click on the Name for more information
Structure Class
achondrites
Chemical Class
Martian (shergottite)
Country
Year found
2001
Mass
812 g
[Museum Collection]
(1) 0.230g


Two stones (414 and 383 g) were found in the Atlas mountains (Morocco) in 2001 January and March. The exact location of find is unknown. The meteorite is a cumulate peridotitic rock consisting of olivine (~55 vol%), low and high-Ca pyroxenes (~35 vol%) and plagioclase glass (~8 vol%). Accessory minerals include phosphates (merrillite), chromite and spinels (inclusions in olivines and pyroxenes), sulfides (pyrrhotite), and a glass rich in potassium.The igneous texture is very similar to that of the ALHA77005. Classification and mineralogy (P. Gillet, ENSL, J.A. Barrat, UAng, M. Bohn, Ifremer): pyroxenes are pigeonite, En78Fs19Wo2-En60Fs26Wo14, and augite, En53Fs16Wo31-En45Fs14Wo41; maskelynite ranges from An57Ab41Or1 to An40Ab57Or3. The key element weight-ratios FeO*/MnO is close to 30 for pigeonite and close to 50 for olivines. Geochemistry: REE pattern similar to that of ALHA77005 but with higher values. Specimens: type specimen, 20 g, ENSL; main mass, Fectay.
Name
*click on the Name for more information
Structure Class
achondrites
Chemical Class
Martian (shergottite)
Country
Year found
2005
Mass
70.1 g
[Museum Collection]
(1) 7.418g (2) 4.678g (3) 4.178g
(4) 3.080g (5) 3.004g (6) 2.975g
(7) 2.508g (8) 2.286g (9) 1.904g




History: A minimally weathered fully encrusted whole stone of 70.1 g was purchased in Erfoud, Morocco, by M. Farmer in November 2005. Petrography: (T. Bunch and J. Wittke, NAU; A. Irving, UWS) A medium-grained (<3.1 mm greatest dimension) basaltic shergottite that consists of ~57.3 vol% augite and pigeonite pyroxenes, and 38.3 vol% plagioclase (present as shock-formed maskelynite and glasses) with minor opaques (2.7 vol%) and phosphates (1.7 vol%) arranged in a weakly foliated subophitic to granular texture. Accessory phases include ulvöspinel, ilmenite, chlorapatite, merrillite, pyrrhotite, Si-Al-Na-K-rich glasses, and baddeleyite. Vesicular black glass veins (