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Northwest Africa 3340
Basic information Name: Northwest Africa 3340
     This is an OFFICIAL meteorite name.
Abbreviation: NWA 3340
Observed fall: No
Year found: 2006
Country: (Northwest Africa)
Mass:help 12.7 g
Meteoritical Bulletin:  MB 92  (2007)  CM2-an
Recommended:  CM2-an    [explanation]

This is 1 of 10 approved meteorites classified as CM2-an.   [show all]
Search for other: Carbonaceous chondrites, Carbonaceous chondrites (type 2), CM chondrites, and CM-CO clan chondrites
Comments: Approved 24 Jul 2007
Revised 1 Dec 2014: Corrected O isotopes
Writeup from MB 92:

Northwest Africa 3340

Algeria or Morocco

Find: April 2006

Carbonaceous chondrite (CM2, anomalous)

History: Purchased by F. Kuntz in April 2006 in Erfoud, Morocco and subsequently acquired for the DuPont Collection at PSF.

Physical characteristics: Two pieces from a very fresh, broken, black, porous stone (total weight 12.7 g) with shiny fusion crust on one side.

Petrography: (A. Irving and S. Kuehner, UWS; T. Bunch, NAU) Sparse mineral grains, carbon-rich objects, dust-armored chondrules and rare refractory inclusion occur in a heterogeneous, very fine grained, porous matrix composed mainly of bladed phyllosilicates with some pentlandite and calcite (clearly visible under incident UV light). Olivine grains (up to 2 mm across) are commonly armored by fine, polycrystalline "dust" and contain inclusions of Ni-rich troilite, chromite, millerite, kamacite and taenite.Both pentlandite and magnesian olivine occur as separate smaller, angular grains. The carbon-rich objects (up to 50 mm across) consist of either pure graphite or a chlorine-rich organic phase. Chondrules consist of PO and POP, many having a fine-grained polycrystalline "dust" rims. One small refractory inclusion is composed of Mg-Al spinel with inclusions of perovskite.

Mineral compositions and geochemistry: Larger zoned olivine grains (e.g., Fa17.9-33.9, Fa39.9-66); smaller homogeneous olivine grains (e.g. Fa1.5, Fa19.9); pentlandite (Ni = 26.2 wt%). Matrix phyllosilicate material could not be analyzed quantitatively, but has very consistent proportions of Mg, Fe, Si and S. The chlorine-rich organic phase contains ~17 wt% Cl and ~32 wt% C, but no detectable N and minor O. Oxygen Isotopes: (D. Rumble, CIW) Replicate analyses by laser fluorination gave, respectively, [values redacted]*.

Classification: Carbonaceous chondrite (CM2, anomalous); minimal weathering. The presence of chlorine-rich carbon compounds, which may be enigmatic chlorinated hydrocarbons, makes this specimen potentially unique among CM chondrites.

Specimens: A total of 2.7 g of sample is on deposit at UWS and the remainder of the mass (10 g) is at PSF.

*) See erratum in MB103

Writeup from MB 103:
NWA 3340, erratum

The oxygen isotopic composition listed in MB92 was incorrect.  The correct data are:

δ18O = 6.224, 7.049; δ17O = 0.494, 1.166; Δ17O = -2.780, -2.542 (all ‰).

Submitted by A. Irving and D. Rumble
Data from:
  Table 2
  Line 12:
Place of purchase:Algeria or Morocco
Mass (g):12.7
Type spec mass (g):2.7
Plots: O isotopes:  
   and collections
NAU: Geology, Bldg 12 Knoles Dr Northern Arizona University, Flagstaff, AZ 86011, United States; Website (institutional address; updated 12 Apr 2012)
PSF: Planetary Studies Foundation,10 Winterwood Lane, Unit B, Galena, Illinois 61036-9283, United States; Website (institutional address; updated 1 Dec 2011)
UWS: University of Washington, Department of Earth and Space Sciences, 70 Johnson Hall, Seattle, WA 98195, United States (institutional address; updated 15 Jan 2012)
CIW: Carnegie Insitution Washington, Geophysical Laboratory, 5251 Broad Branch Rd., NW, Washington DC 20015, United States (institutional address)
DuPont: James M. DuPont Meteorite Collection, Deposited at FMNH in 2008., United States (private address; updated 1 Jun 2012)
Kuntz: Fabien Kuntz, France; Website (private address)
References: Published in Meteoritical Bulletin, no. 92, MAPS 42, 1647-1694 (2007)
Published in Meteoritical Bulletin, no. 103, MAPS 52, 1014, May 2017, http://onlinelibrary.wiley.com/doi/10.1111/maps.12888/full
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     This is 1 of 9429 approved meteorites from (Northwest Africa) (plus 1876 unapproved names)

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