Northwest Africa 15178 (NWA 15178)

(Northwest Africa)

Purchased: 31 Mar 2013

Classification: Ordinary chondrite (H5)

History: A 42.3 g piece of the meteorite was sent to Cascadia by John Shea. Shea purchased a whole stone on March 31, 2013, via e-mail from Mike Bandli Historic Meteorites, who purchased the stone from Caillou Noir in 2003. The sample came with a label from Caillour Noir which listed this as "Unclassified Meteorite #3142" with location as "Sahara" and find date "2002/2003". On January 19, 2021, Martin Goff emailed Cascadia that he hadd "recently acquired a box of NWA Chondrites that came from US collector john/Johannes Shea", including CML 0752.

Physical characteristics: Physical Characteristics: Images sent by John Shea show a fully fusion crusted individual with regmaglypts on one surface and shrinkage cracks on another surface. The fusion crust is black with small brown patches. A small chip along an edge shows a light-colored interior with a protruding metal grain. The cut face on the type specimen is a patchwork of light to medium gray areas with small amounts of yellow/brown discoloration and abundant metal.

Petrography: (M. Hutson, A. Ruzicka, Cascadia): Numerous chondrules can be discerned in thin section, but most lack sharp boundaries with surrounding material. Most feldspathic material is forming feldspathic-chromite assemblages; the single crystalline grains of plagioclase feldspar measured are < 50 µm across, with one exception. Abundant merrillite grains (up to 500 μm across) were observed.

Geochemistry: Olivine: Fa_17.5±0.6, N=31; low-Ca pyroxene: Fs_15.7±0.8Wo_1.2±0.4, N=26.

Classification: Ordinary chondrite (H5) based on texture and chemistry.

Specimens: Cascadia holds 39.9 g in two pieces, as well as a polished thin section; MGoff holds the main mass.