NORTHWEST AFRICA 060


CK5
standby for northwest africa 060 photo
Purchased August 2000
no coordinates recorded

A single 604 g stone was purchased in a market in Erfoud, Morocco by American collectors in August 2000. Black fusion crust still covers the portion of the meteorite that was exposed above the desert sands, while the buried portion is encrusted with desert caliche. The meteorite was classified by Alan Rubin at UCLA as a CK5. Typical of CK chondrites, NWA 060 contains ~75 vol% matrix, 15 vol% chondrules, and 0.5 vol% CAIs (Huber et al., 2006). A few vol% of magnetite is present as grains in the matrix, as curvilinear trails inside of silicates, and as components of small nodules. Minor sulfides, primarily pentlandite and pyrite, also occur. Regions exhibiting crushing were documented by Wasson et al. (2013).

A weathering index (wi) was developed by Rubin and Huber (2005) for the highly oxidized meteorites, such as those of the R chondrite and equilibrated CV chondrite groups. This index is based on the modal abundance of brown-stained silicates as visually determined on a thin section in transmitted light at ~100× magnification; NWA 060 was determined to have an index of wi-5 (severely weathered).

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 chondrites, 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 chondrites. 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. The photo above shows a 0.7 g partial slice of NWA 060, while that below shows the complete mass as found.

standby for northwest africa 060 photo
Photo courtesy of Michael Cottingham, © 2000