NWA 1694

CK3

Found October 2002
no coordinates recorded A single fusion-crusted stone weighing 47.1 g was found in the Sahara Desert and was subsequently purchased in Safsaf, Morocco by American collectors. Classification was conducted at Northern Arizona University (T. Bunch and J. Wittke). This very fresh findMeteorite not seen to fall, but recovered at some later date. For example, many finds from Antarctica fell 10,000 to 700,000 years ago. (W0/1) is classified as an unshocked (S1) CK3. Northwest Africa 1694 is composed of 47 vol% fine-grained matrixFine grained primary and silicate-rich material in chondrites that surrounds chondrules, refractory inclusions (like CAIs), breccia clasts and other constituents., 44 vol% chondrulesRoughly spherical aggregate of coarse crystals formed from the rapid cooling and solidification of a melt at  ~1400 ° C. Large numbers of chondrules are found in all chondrites except for the CI group of carbonaceous chondrites. Chondrules are typically 0.5-2 mm in diameter and are usually composed of olivine (up to 1.2 mm), 6 vol% sulfides (containing inclusions of chlorapatite and silicaSilicon dioxide, SiO2. glass), 2 vol% Cr-rich magnetiteFe oxide, FeFe2O4, containing oxidized iron (Fe) found in the matrix of carbonaceous chondrites and as diagnostic component in CK chondrites. In CK chondrites, magnetite is typically chromian, containing several wt. % Cr2O3., and 1 vol% CAIsSub-millimeter to centimeter-sized amorphous objects found typically in carbonaceous chondrites and ranging in color from white to greyish white and even light pink. CAIs have occasionally been found in ordinary chondrites, such as the L3.00 chondrite, NWA 8276 (Sara Russell, 2016). CAIs are also known as refractory inclusions since they. Although this meteoriteWork in progress. A solid natural object reaching a planet’s surface from interplanetary space. Solid portion of a meteoroid that survives its fall to Earth, or some other body. Meteorites are classified as stony meteorites, iron meteorites, and stony-iron meteorites. These groups are further divided according to their mineralogy and is similar to NWA 772, the two are not considered to be paired.

After in-depth analyses of many CV and CK meteorites having a wide range of petrologic types was conducted by Wasson et al. (2013), they presented a reasoned argument for merging the CK and CV groups into a single unified group. The geochemical and petrological justification for such a reclassification of the CK chondritesChondrites are the most common meteorites accounting for ~84% of falls. Chondrites are comprised mostly of Fe- and Mg-bearing silicate minerals (found in both chondrules and fine grained matrix), reduced Fe/Ni metal (found in various states like large blebs, small grains and/or even chondrule rims), and various refractory inclusions (such, along with details of their proposed taxonomic scheme, can be found on the Dhofar 015 page. Subsequent studies have demonstrated a high likelihood for separate parent bodies. One such study conducted by Dunn et al. (2016) compared magnetite in a number of CK and CV chondritesMeteorite class named after the Vigarano meteorite that fell in Italy in 1910. They have abundant large, well-defined rimless (?) chondrules of magnesium-rich olivine (~0.7 mm diameter; 40-65 vol. %), often surrounded by iron sulfide. They also contain 7-20 vol. % CAIs. The often dark-gray matrix is dominated by Fe-rich. They presented geochemical, mineralogical, and petrographic evidence which is more consistent with separate CV and CK parent bodies. Another study conducted by Yin et al. (2017) utilized a coupled Δ17O vs. ε54Cr diagram to plot several CK and CV chondrites. Through this technique they demonstrated that these two meteorite groups derive from separate parent bodies. Details of these studies can also be found on the Dhofar 015 page.

Our collections contain less than 20 different meteorites representating unequilibrated CK material. The specimen shown above is a 2.2 g partial slice of CK3 NWA 1694, however, a subtype has not yet been ascertained.