Three‐dimensional petrography of the Tucson meteorite

Jon M. Friedrich, Michael K. Weisberg, Lucille C. Malecek, C. E. Nehru

Meteoritics & Planetary Science
First Published: 27 October 2021


“We use X-ray microtomography (µCT) and digital data extraction techniques for the three-dimensional (3-D) petrographic investigation of the Tucson meteorite. Our results show that the silicate-free metal regions in Tucson exist as discrete objects surrounded by a continuous silicate-containing metal “matrix.” Volumetric measurements of the silicate-free metal regions in Tucson demonstrate that they are akin to the sizes of metallic nodules found in CBa chondrites. Silicate-free metal regions have bladed or prolate shapes. Nonmetallic minerals in Tucson are predominately equant or prolate in shape. Nonmetallic mineral grains and silicate-free metal regions in Tucson share a common orientation and are part of a petrofabric composed of a lineation. Any foliation in Tucson is weakly developed. We interpret the petrofabric as being the result of a single event on the Tucson parent body, during which Tucson experienced shearing forces. Our 3-D petrographic investigation supports the idea that Tucson is an unusual member of the CR chondrite clan.”