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Errachidia 004
Basic information Name: Errachidia 004
     This is an OFFICIAL meteorite name.
Abbreviation: There is no official abbreviation for this meteorite.
Observed fall: No
Year found: 2020
Country: Morocco
Mass:help 2.64 kg
Classification
  history:
Recommended:  Winonaite    [explanation]

This is 1 of 59 approved meteorites classified as Winonaite.   [show all]
Search for other: Primitive achondrites, Winonaites
Comments: Approved 13 Mar 2021
Writeuphelp
Writeup from MB 110:

Errachidia 004        32°2.418’N, 4°4.092’W

Errachidia, Morocco

Find: 2020

Classification: Primitive achondrite (Winonaite)

History: Found in 2020 by Mustapha Oulkouch and other finders in a strewnfield centered within the isolated rural community of Oued Naam. Later purchased by Sean Mahoney in February 2020.

Physical characteristics: Many small stones and fragments covered with a weathered fusion crust. 75% of the stones contain low amounts of visible metal; the remaining 25% contain high amounts of visible metal.

Petrography: (D. Sheikh, FSU) This sample features two distinct lithologies: 1) A low-metal lithology (<10 vol% metal) displaying a predominantly granoblastic texture composed of forsterite, enstatite, augite, and sodic plagioclase (Silicate grain size Av. 110±50 µm) with the mineral grain boundaries meeting at approximately 120° triple junctions. Kamacite and troilite are finely scattered throughout the interior as either veinlets or individual grains; some have been altered to form Fe-oxides. No chondrules were observed. 2) A high-metal lithology (up to 80 vol% metal) displaying a well-developed Widmanstätten pattern containing kamacite, taenite, plessite, and accessory troilite and schreibersite (kamacite band width Av. 2 mm, range 1-3 mm), and containing angular silicate inclusions of sodic plagioclase (some containing melt inclusions), augite, and enstatite (Silicate grain size Av. 350±50 µm). No chondrules were observed.

Geochemistry: Low-metal lithology: Forsterite (Fa0.8±0.3, range Fa0.4-1.4, FeO/MnO=2±1, n=30), Enstatite (Fs4.3±0.6 Wo1.7±0.2, range Fs1.6-4.9 Wo0.8-2.0, FeO/MnO=4±1, n=22), Augite (Fs2.0±0.4 Wo45.0±1.0, range Fs1.2-2.6 Wo44.1-46.7, Na2O=0.7±0.2 wt%, Cr2O3=1.1±0.6 wt%, FeO/MnO=3±1, n=7), Sodic Plagioclase (An10.8±0.8 Or4.0±1.6, range An10.2-11.4 Or2.8-5.1); High-metal lithology: Sodic Plagioclase (An12.2±2.6 Or3.9±0.6, range An9.7-19.5 Or1.9-5.3), Augite (Fs2.4±0.3 Wo43.0±1.1, range Fs1.8-3.0 Wo39.9-45.7, Na2O=0.9±0.1 wt%, Cr2O3=1.5±0.1 wt%, FeO/MnO=3±1, n=19), Enstatite (Fs4.5±0.5 Wo1.8±0.3, range Fs3.9-5.7 Wo1.4-2.2, FeO/MnO=4±1, n=8). Oxygen isotopes (K. Ziegler, UNM): analyses of acid-washed subsamples by laser fluorination gave, respectively, Low-metal lithology: (δ17O 2.296, 3.022, 2.588; δ18O 5.276, 6.655, 5.843; Δ17O -0.489, -0.491, -0.497 per mil), High-metal lithology: (δ17O 3.940, 2.666, 2.577; δ18O 8.197, 6.019, 5.881; Δ17O -0.388, -0.512, -0.528 per mil). ICP-MS data of metal separates from high-metal lithology, using sample of North Chile (Filomena) as standard (C. Herd and P. Hill, UAb): Ni = 7.4, Co = 0.30 (both wt%); Ir = 5.9, Ga = 28, Ge = 123, As = 10.1, Ru = 5.0, Re = 0.5, Os = 13.6, Pt = 9.5, Cu = 180, Au = 0.85 (all μg/g).

Classification: Primitive achondrite (Winonaite). The unusual occurrence of two distinct lithologies within this sample suggests a transitional classification between an endmember winonaite (low-metal lithology) and a silicate-rich IAB-complex iron (high-metal lithology). This is supported by the oxygen isotopes, texture, and mineral abundances and compositions for both distinct lithologies, and the siderophile element abundances of metal separates from the high-metal lithology.

Specimens: 25.2 g type specimen and two polished thin sections (one of each lithology) at UNM; 397 g high-metal and 905 g low-metal with Sean Mahoney, 65 g high-metal and 50 g low-metal with Juan Aviles Poblador, 215 g high-metal and 85 g low-metal with Kyle Josefy, 800 g low-metal with Mark Lyon, 61 g high-metal and 61 g low-metal with Topher Spinnato.

Data from:
  MB110
  Table 0
  Line 0:
State/Prov/County:Errachidia
Origin or pseudonym:Oued Naam
Date:2020
Latitude:32°2.418'N
Longitude:4°4.092'W
Mass (g):2639
Pieces:hundreds
Class:Winonaite
Shock stage:low
Weathering grade:moderate
Classifier:D. Sheikh, FSU; K. Ziegler, UNM; C. Agee, UNM
Type spec mass (g):25.2
Type spec location:UNM
Main mass:Sean Mahoney
Comments:Submitted by Daniel Sheikh
Plots: O isotopes:  
Institutions
   and collections
UNM: Institute of Meteoritics MSC03 2050 University of New Mexico Albuquerque NM 87131-1126 USA, United States; Website (institutional address; updated 12 Feb 2015)
UAb: 1-26 Earth Sciences Building, University of Alberta, Edmonton, AB, T6G 2E3, Canada, Canada; Website (institutional address; updated 17 Oct 2011)
FSU: Department of Geological Sciences, Florida State University, Tallahassee FL 32306-4100, United States (institutional address; updated 16 Dec 2010)
Catalogs:
References: Published in Meteoritical Bulletin, no. 110, in preparation (2021)
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Photos:
CreditPhotos
Public domain photographs:
Daniel Sheikh                        
Geography:

Morocco
Coordinates:
     Recommended::   (32° 2' 25"N, 4° 4' 6"W)

Statistics:
     This is 1 of 3 approved meteorites from Errachidia, Morocco
     This is 1 of 1652 approved meteorites from Morocco (plus 23 unapproved names) (plus 1 impact crater)
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