IIIAB
Name
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Structure Class
Iron
Chemical Class
IIIAB
Country
Mexico
Year found
unknown
Mass
10 kg
[Museum Collection]
(1) 17.6g (2) 15.9g (3) 12.8g (4) 11.2g
(5) 10.8g (6) 10.4g
History: (D. Hill, UAz) One meteorite specimen was found by Mr. Aguilar (date unknown) near a ranch 70 km east of Guerrero Negro, Baja California, Mexico, on a rocky mountain (probably near Rancho). Friends of the finder brought an endcut of the meteorite to the U. of Arizona for examination. It was eventually sold to a group of meteorite dealers in 2019. Physical characteristics: Total mass of a single specimen is approximately 10 kg. Dimensions are 30.5 × 16 × 5 cm and tapers on one end. It is irregularly shaped and flat on one side. The meteorite’s unusual shape is defined by a 10 cm cavity where an inclusion melted and ablated away during atmospheric passage. The specimen exhibits an oxidized brown to black-brown, weathered fusion crust with pits up to 7 mm in diameter over the entire surface. There are some whitish and bluish paint spots on the exterior. The meteorite has deep regmaglypts and large rounded regions ranging from a few cm across to 11 cm diameter and 4 cm deep where inclusions probably melted and softened during entry through the atmosphere. Petrography: (D. Hill, UAz) Widmansatten pattern exhibits kamacite with average bandwith of 1.48±0.48 mm; largest bands are 3 mm wide. Kamacite bands are stubby in length; up to 10 mm. Taenite is zoned with plessite interiors, most commonly comb plessite. Schreibersite tends to occur near pinched ends of taenite and as ribbons adjacent to taenite. Sulfides are present as 2 mm grains and complex, fine grained, spider-like regions containing kamacite, pentlandite, and schreibersite with nickel-bearing troilite as 10 μm raisin-like inclusions. Geochemistry: Mineral compositions and geochemistry: (D. Hill, UAz): EMP data, kamacite: Fe = 92.47, Ni = 6.63; taenite: Fe = 63.77 Ni = 35.33 (all in %). Average composition: (N. Chabot, JHUAPL and R. Ash, UMD), LA-ICP-MS data (four laser tracks), Co = 4980±180, Cu = 180±30, Ga = 16.6±0.4, Ge = 37±1, As = 6.4±0.9, Ir = 0.238±0.028, Au = 0.72±0.03 (all in ppm). Distance, physical characteristics, and composition preclude pairing with Loreto (IIIAB), Mexico. Classification: Iron, IIIAB. Coarse octahedrite. Specimens: Type specimen: 311 g UAz
Name
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Structure Class
Iron
Chemical Class
IIIAB
Country
Australia
Year found
1931
Mass
2 t
[Museum Collection]
(1) 38.9g (2) 25g (3) 6g
BASEDOW RANGE, ? Stone.
Literature: 1. Geochim. et Cosmochim. Acta, 1957, v.11, No 4, 263-278, B литературе не описан.
Name
*click on the Name for more information
Structure Class
Iron
Chemical Class
IIIAB
Country
Peru
Year found
1950
Mass
141 kg
[Museum Collection]
(1) 10.10g (2) 6.85g
Literature: 1. Bol. Inst. Nac. Invest. y Formento Mineros, Peru, 1950, v.1, No. 1, pp. 141-148 /MA-12-361/ /MA-12-612/.
Name
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Structure Class
Iron
Chemical Class
IIIAB
Country
Poland
Year found
2012
Mass
7.6 kg
[Museum Collection]
(1) 26.38g (2) 29.53g
History: The metorite was found during a search for military armaments from WW II. Petrography: This structural description mainly based on a heavily etched slab with a total area (on opposite sides) of 40 cm2. Neumann lines in different orientations are densely spaced in the kamacite. Small FeS inclusions are common, typically 3×1 mm. Kamacite shows evidence of impact-associated reheating. Swathing kamacite around FeS has recrystallized to small (mm-size) grains. Sample is moderately weathered near the surface; one dark oxide grain has dimensions of 5×8 mm. No heat-altered zone has been recognized. Examination of a small polished section showed tiny rhabdites to be common with some coarser schreibersite (typically 20×400 μm). Troilite grains commonly show daubreelite lamellae. Cu metal has been noted as an inclusion near troilite. Cohenite was found as a rim on a μm-size troilite-daubreelite nodule. Geochemistry: Composition: Co, 5.01 mg/g; Ni, 73.7 mg/g; Ga, 19.8 μg/g; Ge,
Name
*click on the Name for more information
Structure Class
Iron
Chemical Class
IIIAB
Country
Canada
Year found
2007
Mass
5.37 kg
[Museum Collection]
(1) 40.31g
History: Four small fragments were found buried adjacent to a circular depression by two local residents using a metal detector. The circular depression was subsequently confirmed as a 36 m diameter Late Holocene impact crater based on morphology, identification of impact ejecta and crater fill, and presence of impact melt (C. Herd and D. Froese, University of Alberta), and further fragments were recovered. Physical characteristics: The meteorite consists of 74 samples with a total mass of 5372 g. The samples were found buried up to 25 cm and have a red-brown exterior. Petrography: (C. Herd, University of Alberta, UAb) Widmanstätten pattern with an average bandwidth of 0.8 ± 0.2 mm and areas of plessite are evident on polished and etched surfaces. Locally, kamacite lamellae are coarser and taenite lamellae are offset as a result of shock deformation and recrystallization. Rare Fe-Ni phosphide inclusions are present. Mineral compositions and geochemistry: Bulk composition: INAA data (J. Duke, UAb): Ni = 8.11 ± 0.13 wt%, Co = 4950 ± 100 μg/g, Ir 10.3 ± 0.5 μg/g, (uncertainties 1σ, 68% confidence level), Ge ≤ 40 μg/g, indicate the IIIAB group. Classification: Iron, IIIAB medium octahedrite, extensive shock, moderate weathering. Type specimens: A total of 2.4 kg is on deposit at UAb. The remainder of the known material is held by the anonymous finders.
Name
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Structure Class
Iron
Chemical Class
IIIAB
Country
Morocco
Year found
2008
Mass
50 kg
[Museum Collection]
(1) 36.43g
History: Purchased near side of road near Khouribga, Morocco. Physical characteristics: Heavy weathering around the perimeter and along a crack; near one edge oxidation penetrates about 1 cm into the interior, with kamacite largely replaced by oxides in fields of fine plessite. Petrography: (J.T. Wasson, UCLA): Medium octahedrite, band-width 1.2 mm. Schreibersite is present in the interiors of larger kamacite bands; a typical size is 2 × 0.3 mm. No FeS was observed. Geochemistry: Compositional data: Co 5.2 mg/g; Ni 84 mg/g; Ga 21.5 μg/g; Ge
Name
*click on the Name for more information
Structure Class
Iron
Chemical Class
IIIAB
Country
(Northwest Africa)
Year found
2012
Mass
2.23 kg
[Museum Collection]
(1) 41.41g
Petrography: The examined polished surface has an area of about 15 cm2; an additional 30 cm2 is sawed surface with features >0.4 mm across visible. Meteorite is moderately weathered with oxidation revealing the kamacite bandwidth to be about 1.2±0.2 mm, similar to the highest in IIIAB. On the polished surface no inclusions >0.1 mm in maximum dimensions were observed; in the remaining 30 cm2 no inclusions >0.4 mm were observed. Geochemistry: Composition: Co, 5.02 mg/g; Ni, 79.8 mg/g; Ga, 20.4 μg/g; Ge,