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Northwest Africa 7891
Basic information Name: Northwest Africa 7891
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 7891
Observed fall: No
Year found: 2012
Country: Morocco
Mass:help 168 g
Classification
  history:
Meteoritical Bulletin:  MB 102  (2013)  CV3-an
Recommended:  CV3-an    [explanation]

This is 1 of 5 approved meteorites classified as CV3-an.   [show all]
Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 3), CV chondrites, and CV-CK clan chondrites
Comments: Approved 4 Jun 2013
Writeuphelp
Writeup from MB 102:

Northwest Africa 7891 (NWA 7891)

Morocco

Purchased: 2012

Classification: Carbonaceous chondrite (CV3, anomalous)

History: Purchased by Aziz Habibi in Morocco, 2012.

Physical characteristics: Single stone, dark weathered fusion crust, saw-cut reveals many chondrules and CAIs of variable size.

Petrography: (C. Agee, UNM) Microprobe examination of a polished mount shows numerous PO and POP chondrules, many with irregular shapes, set in fine-grained groundmass.

Geochemistry: (C. Agee, UNM) Type I chondrule olivine Fa0.8±0.3, Cr2O3=0.18±0.08, CaO=0.44±0.19 wt%, n=9, Type II chondrule olivine Fa10.6±10.0, range Fa1.9-40.2, Fe/Mn=69±69, Cr2O3=0.12±0.14, CaO=0.20±0.12 wt%, n=25; enstatite Fs1.1±0.2Wo1.9±0.9, n=23; diopside Fs2.8±2.6Wo34.5±0.7, n=4. (Karen Ziegler, UNM) Oxygen isotope mean values of analyses on four acid-washed aliquots of bulk sample, 0.9, 1.2, 1.5, 1.4 mg, gave δ17O= -18.662, -15.455, -7.616, -6.818, δ18O= -15.420, -11.700, -4.201, -2.390, Δ17O= -10.520, -9.277, -5.398, -5.556 (linearized, all permil).

Classification: Carbonaceous chondrite, CV3 anomalous, based on wide range of O-isotope values, all on the CCAM line, in particular three bulk analyses with low values far outside the CV3 range, also mean value Fe/Mn of ferroan olivines is anomalously low with relatively high standard deviation.

Specimens: 20.25 g including a probe mount on deposit at UNM, Aziz Habibi holds the main mass.

Data from:
  MB102
  Table 0
  Line 0:
Place of purchase:Morocco
Date:P 2012
Mass (g):168
Pieces:1
Class:CV3-an
Fayalite (mol%):0.8±0.3, 10.6±10.0
Ferrosilite (mol%):1.1±0.2, 2.8±2.6
Wollastonite (mol%):1.9±0.9, 34.5±0.7
Classifier:C. Agee, UNM
Type spec mass (g):20.25
Type spec location:UNM
Main mass:Aziz Habibi
Comments:Submitted by C. Agee
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)
Catalogs:
References: Published in Meteoritical Bulletin, no. 102, MAPS 50, 1662, September 2015
Find references in NASA ADS:
Find references in Google Scholar:
Geography:

Morocco
Coordinates:Unknown.

Statistics:
     This is 1 of 1390 approved meteorites from Morocco (plus 16 unapproved names) (plus 1 impact crater)

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