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Northwest Africa 2405
Basic information Name: Northwest Africa 2405
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 2405
Observed fall: No
Year found: 2018
Country: (Northwest Africa)
Mass:help 454 g
Classification
  history:
Recommended:  Eucrite-br    [explanation]

This is 1 of 167 approved meteorites classified as Eucrite-br.   [show all]
Search for other: Achondrites, Eucrites, and HED achondrites
Comments: Approved 7 Nov 2019
Writeuphelp
Writeup from MB 108:

Northwest Africa 2405 (NWA 2405)

(Northwest Africa)

Purchased: Jan 2018

Classification: HED achondrite (Eucrite, brecciated)

History: The meteorite was exported from Morocco to Tucson where it was purchased by N. Gessler.

Physical characteristics: 20% fusion crusted. The interior displays a distinctive structure of angular pale tan clasts of basalt (3/4) set in a subordinate proportion (1/4) of dark grey, vein-like (shock-melted) materials, with vein widths ranging from indiscerniblly thin to approximately, locally, 3 mm.

Petrography: The rock consists predominantly of clasts of little-brecciated subophitic basalt, with grain sizes generally near 1 mm, with a typical pyroxene and plagioclase dominated eucritic mode, and displaying typical eucritic thermal-metamorphic exsolution in pyroxene. The shock state of the clastic matter varies; locally, its plagioclase has been partially maskelynitized. The subordinate component of shock-melt vein material that choaotically criss-crosses the rock is much finer grained.

Geochemistry: Low-Ca pyroxene clusters near Fs61Wo2, augite near Fs27Wo43, both typical for a noncumulate eucrite. Pyroxene FeO/MnO averages (26 analyses) 31.5. Plagioclase (8 analyses) is An88-90. The bulk composition, determined by INAA and fused-bead EPMA applied to 2 chips totaling 650 mg, is fairly nondescript for a eucrite, with bulk Mg/(Mg+Fe) ~ 38 mol%, 0.6 wt% TiO2, and 0.44 wt% Na2O; and shows little difference between a chip dominated (~70%) by dark shock-vein matter and a chip of preponderantly (~95%) pale tan clastic matter.

Classification: Eucrite, brecciated.

Specimens: Main mass with Gessler, type specimen at UCLA.

Data from:
  MB108
  Table 0
  Line 0:
Place of purchase:Tucson
Date:P Jan 2018
Mass (g):454
Pieces:1
Class:Eucrite-br
Weathering grade:mild
Ferrosilite (mol%):61 (low-Ca), 27 (high-Ca)
Wollastonite (mol%):2 (low-Ca), 43 (high-Ca)
Classifier:P. Warren, UCLA
Type spec mass (g):28
Type spec location:UCLA
Main mass:Nick Gessler
Finder:Anonymous
Comments:Gessler's address: 2010 Calgary Lane, Los Angeles, CA 90077; submitted by Paul Warren
Institutions
   and collections
UCLA: Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90095-1567, United States (institutional address; updated 17 Oct 2011)
Gessler: Nicholas Gessler, 2010 Calgary Lane, Los Angeles, CA 90077, United States (private address; updated 7 Jul 2016)
Catalogs:
References: Published in Meteoritical Bulletin, no. 108, in preparation (2019)
Find references in NASA ADS:
Find references in Google Scholar:
Geography: 
Coordinates:Unknown.

Statistics:
     This is 1 of 7005 approved meteorites from (Northwest Africa) (plus 2002 unapproved names)

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