Meteoritical Bulletin: Entry for Northwest Africa 7978

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Northwest Africa 7978

Basic information

Name: Northwest Africa 7978
This is an OFFICIAL meteorite name.
Abbreviation: NWA 7978
Observed fall: No
Year found: 2013
Country: Morocco
Mass: 681 g

Classification
history:

Meteoritical Bulletin:	MB 102	(2013)	L3.10
Recommended:			L3.10 [explanation]

This is 1 of 6 approved meteorites classified as L3.10. [show all]
Search for other: L chondrites, L chondrites (type 3), Ordinary chondrites, and Ordinary chondrites (type 3)

Comments:

Approved 12 Sep 2013

Writeup

help

Writeup from MB 102:

Northwest Africa 7978 (NWA 7978)

Morocco

Purchased: 2013

Classification: Ordinary chondrite (L3.10)

History: Purchased by Brahim Tahiri from a Moroccan hunter and sent Sean Tutorow for classification, 2012.

Physical characteristics: Three matching stones, dark weathered fusion crust, saw cut reveals many densely packed white chondrules of variable size, set in dark-gray matrix.

Petrography: (C. Agee, UNM) Microprobe examination of a polished mount shows numerous unequilibrated chondrules, many are porphyritic, apparent mean diameter 498±335 μm, range measured 100-1500 μm, n=43. Abundant opaque matrix, most chondrules with glass or mesostasis.

Geochemistry: (C. Agee and N. Muttik, UNM) Ferroan olivine Fa_17.0±7.7, Fe/Mn=46±19, Cr₂O₃=0.31±0.25 wt%, CaO=0.13±0.06 wt%, n=27; low-Ca pyroxene Fs_8.9±5.7Wo_2.6±5.5, Fe/Mn=22±14, n=23; augite Fs_16.3±15.6Wo_31.3±7.7, Fe/Mn=16±12, n=3.

Classification: Ordinary chondrite (L3.10), type 3.10 based on ferroan olivine mean Cr₂O₃ content and sigma from Grossman and Brearley (2005). Weathering grade W2.

Specimens: 22.5 g including a probe mount on deposit at UNM, Sean Tutorow holds the main mass.

Bibliography:

Grossman J.N. and Brearley A.J. (2005) The onset of metamorphism in ordinary and carbonaceous chondrites. Meteorit. Planet. Sci. 40, 87-122. (link)

Data from:
  MB102
  Table 0
  Line 0:

Place of purchase:	Morocco
Date:	P 2013
Mass (g):	680.7
Pieces:	3
Class:	L3.10
Weathering grade:	W2
Fayalite (mol%):	17.0±7.7
Ferrosilite (mol%):	8.9±5.7
Wollastonite (mol%):	2.6±5.5
Classifier:	C. Agee, UNM
Type spec mass (g):	22.5
Type spec location:	UNM
Main mass:	Sean Tutorow
Comments:	Field name G-409; submitted by C. Agee

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:

Photos:

Credit	Photos
Photos uploaded by members of the Encyclopedia of Meteorites. (Caution, these are of unknown reliability)
John Tanner

Geography:

Morocco

Morocco

Coordinates:

Unknown.

Statistics:
This is 1 of 1611 approved meteorites from Morocco (plus 22 unapproved names) (plus 1 impact crater)

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