Iron, ungrouped plessitic octahedrite
Found 2000
no coordinates recorded
Many individual masses from this shower-producing meteorite have been recovered in Taza, Morocco, having a total weight of 75.3 kg. This meteorite has been assigned number 859 in the NWA series. Many of the masses have well-oriented shapes.
Taza is chemically anomalous and unrelated to any established iron chemical group. However, Taza has an elemental composition very similar to the ungrouped, plessitic iron, Butler, and the two may be grouped together (see table below). They have an extremely high Ge concentration of ~2000 ppm (Taza varies from 1500–5000 ppm), four times higher than any other iron meteorite. A high Ni content of ~16% promotes kamacite to form discontinuous, pointed spindles, rimmed by taenite, having widths of ~0.15 mm. Tetrataenite (~50% Ni) forms a narrow border on some kamacite spindles. In the dense, fine-grained plessite matrix, this spindle pattern is repeated on a scale ten times finer to form a µm-sized Thomson (Widmanstätten) structure. This uncommon plessitic microstructure is transitional between the octahedrites and the ataxites.
The specimen of Taza shown above is a 13.42 g etched partial slice that displays kamacite spindles in a Thomson (Widmanstätten) pattern.
Comparison of Volatile Element Abundances for Taza and Butler
