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Gueltat Zemmour
Basic information Name: Gueltat Zemmour
     This is an OFFICIAL meteorite name.
Abbreviation: There is no official abbreviation for this meteorite.
Observed fall: Yes, confirmed fall
Year fell: 2018
Country: Western Sahara
Mass:help 8 kg
Meteoritical Bulletin:  MB 107  (2018)  L4
Recommended:  L4    [explanation]

This is 1 of 2072 approved meteorites (plus 5 unapproved names) classified as L4.   [show all]
Search for other: L chondrites, L chondrites (type 4-7), Ordinary chondrites, and Ordinary chondrites (type 4-7)
Comments: Approved 24 Dec 2018
Revised 24 Feb 2018: changed to confirmed fall
Writeup from MB 107:

Gueltat Zemmour        25°05’32.0’’N, 12°37’23.9’’W

Boujdour, Morocco

Fall: 21 Aug 2018

Classification: Ordinary chondrite (L4)

History: (H. Chennaoui Aoudjehane FSAC, UH2C, Ahmed Bouferra, Mohamed Aid, "Moroccan association of meteorites"). On 21 Aug 21 2018 around 14:20, many people from the south of Morocco saw a bright fireball. In Smara, Seddiki Mbarek reported the passing of a fireball similar to a yellow-white shining star, moving from the northeast to southwest, in the direction of Gueltat Zemmour. His son Aboubakr also saw the fireball, saying that his sighting only lasted a few seconds before a building blocked the view. Abderrahmane Latifi and his son Adil, also from Smara, both saw a fireball shining red, then yellow, brighter than the Sun, lasting about 3 s. In the fall area, Mahjoub Boutabâa, a nomad, was inside his tent; he heard a sound similar to the explosion of a mine, followed by a few sonic booms that resonated in the entire Oued Labiyad valley, similar to thunder. Abba Essahed, another nomad, and his wife Basaddouk Aicha were out of their tent when they heard a whistling sound almost identical to ocean waves, then five sonic booms akin to the explosion of a mine, making them feel like the mountains would crumble. They saw a very bright fireball comparable to a burning 4x4 vehicle in terms of size, first red then yellow, more dazzling than the Sun, with a flashing light moving from north to south for a few seconds. There was smoke in the sky directly above them. Aicha was so scared that she went to hide between the water barrels. All testimonies are concordant on the date and the time of August 21 around 14:20. Due to the period of the fall (one day before "Aid El Adha"), hunters could not search immediately. Searching began ten days after the fall and the first pieces were found in mid-September, about three weeks after the fall, a few km to the west of Gueltat Zemmour. A group of hunters: Mohamed Ouicha, Brahim Ouhra, Mbarek Amediaz, Aissa Ouicha and Brahim Ouaadjou found many pieces (5.1, 5.0, 6.3, 7.2, and 15 g) in a valley between Wad Awzireft and Wad Labiyad (N25°05’32.0’’; W12°37’23.9’’) and north of Koudiat Rjilya. Bigger pieces were found SW of this site (N24°53’29.52"; W12°42’10.5’’ ; around 700 g) (N24°56’37.06"; W12°40’52.12’’; around 200 g). The direction of the fall was NNE-SSW and the strewnfield is about 12 km.

Physical characteristics: A few small pieces totalling around 500 g and 3 bigger ones (5448 g, 1374 g and 426 g) not weathered, totally covered by a black matte fusion crust, showing fine  grains, very friable material, and easily discernable chondrules. Large pieces are broken and show a gray-colored interior; they are partially covered by fusion crust.

Petrography: (H. Chennaoui Aoudjehane UH2C, L. Folco UniPi) Numerous well-defined chondrules (POP, PO, GPO, PP, RP and glassy chondrules) up to 3 mm. Plagioclase is very small (2 µm maximum). Mesostasis is microcrystalline. Most metal and sulfides are automorphous grains, um sized, to large grains up to 500 um; they occur inside chondrules as small grains, in the mesostasis as small and large grains, and surrounding some chondrules.

Geochemistry: (V. Moggi Cecchi, UniFi, H. Chennaoui Aoudjehane UH2C) Olivine Fa26.0±0.7 Fe/Mn=51.23 (N=10), low-Ca pyroxene Fs20.7±0.8Wo1.1±0.5 Fe/Mn=28.51 (N=7), plagioclase An8.2±2.4Or4.8±0.8 (N=3), Taenite Ni 50.3±2.7 (N=3) Whole-rock trace-element concentrations by ICP-MS (M. D’Orazio, UniPi): V 59, Cr 2799, Ni 10115, Co 399, La 0.329, Ce 0.879, Pr 0.138, Nd 0.645, Sm 0.211, Eu 0.088, Gd 0.284, Tb 0.054, Dy 0.364, Ho 0.081, Er 0.242, Tm 0.035, Yb 0.236, Lu 0.038 (units = µg/g). Cosmogenic radionuclides: (Å. Rosén, B. Hofmann, NMBE,  GeMSE): Gamma-spectroscopy performed in October 2018 on a 21.74 g sample showed the presence of several short-lived cosmogenic radionuclides (57Co, 46Sc, 56Co, 58Co, 7Be ( t1/2= 53 d; 84.6±10/-7 dpm/kg) and 48V (t1/2= 16 d; 17.8±4.6/-5.4 dpm/kg). Recalculated to August 21, 2018 the 22Na/26Al activity ratio is 1.69±0.1. These data confirm that it is a fresh fall. The 26Al activity of 55.5±3.6/-3.1 dpm/kg and absence of detected 60Co (<0.8 dpm/kg) indicates only a few cm of shielding.

Classification: L4

Specimens: A sample of 20.1 g provided by the "Moroccan association of meteorites", small pieces totaling 30 g provided by Aaronson, FSAC. Aaranson: 1374 + 426 g; Mohamed Aid: 5448 g; Private collector, Casablanca: 21 + 7.2 + 6.3 + 5.1 + 5 g.

Data from:
  Table 0
  Line 0:
Origin or pseudonym:Gueltat Zemmour
Date:21 Aug 2018
Mass (g):~8000
Shock stage:S2
Weathering grade:W0
Fayalite (mol%):26.0±0.7 (n=10)
Ferrosilite (mol%):20.7±0.8 (n=7)
Wollastonite (mol%):1.1±0.5 (N=7)
Magnetic suscept.:4.95
Classifier:H. Chennaoui Aoudjehane, FSAC
Type spec mass (g):50.1
Type spec location:FSAC
Main mass:Aaronson, Mohamed Aid
Finder:Mohamed Ouicha, Brahim Ouhra, Mbarek Amediaz, Aissa Ouicha and Brahim Ouaadjou
Comments:Submitted by H. Chennaoui Aoudjehane
   and collections
NMBE: Natural History Museum Bern Bernastrasse 15 CH-3005 Bern Switzerland, Switzerland; Website (institutional address; updated 2 Mar 2012)
TM: Geoscience Museum, Transvaal Museum, P. O. Box 413, Pretoria 0001, South Africa (institutional address; updated 3 Mar 2011)
UH: Hawai'i Institute of Geophysics and Planetology, School of Ocean and Earth Science and Technology, University of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, United States (institutional address; updated 25 Oct 2011)
FSAC: Universite Hassan II Casablanca, Faculte des Sciences Ain Chock, Departement de Géologie, BP 5366 Maârif, Casablanca, Morocco (institutional address; updated 9 Jan 2013)
Aaronson: Sahara Overland Ltd., Harhora, Temara, 12000, Morocco (private address; updated 3 Jan 2010)
UniFi: Università degli Studi di Firenze, P.zza S. Marco, 4 - 50121 Firenze, Italy (institutional address; updated 14 Sep 2013)
References: Published in Meteoritical Bulletin, no. 107, MAPS 55, 460-462
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Photos uploaded by members of the Encyclopedia of Meteorites.
    (Caution, these are of unknown reliability)
Woreczko Jan & Wadi   

Western Sahara
     Recommended::   (25° 5' 32"N, 12° 37' 24"W)

     This is 1 of 281 approved meteorites from Western Sahara (plus 20 unapproved names)
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