Find: 1 July 1 2007
Iron, medium octahedrite (IIIAB)
Four small fragments were found buried adjacent to a circular depression by two local residents using a metal detector. The circular depression was subsequently confirmed as a 36 m diameter Late Holocene impact crater based on morphology, identification of impact ejecta and crater fill, and presence of impact melt (C. Herd and D. Froese, University of Alberta), and further fragments were recovered.
The meteorite consists of 74 samples with a total mass of 5372 g. The samples were found buried up to 25 cm and have a red-brown exterior.
Widmanstätten pattern with an average bandwidth of 0.8 ± 0.2 mm and areas of plessite are evident on polished and etched surfaces. Locally, kamacite lamellae are coarser and taenite lamellae are offset as a result of shock deformation and recrystallization. Rare Fe-Ni phosphide inclusions are present.
Mineral compositions and geochemistry:
Bulk composition: INAA data (J. Duke, UAb): Ni = 8.11 ± 0.13 wt%, Co = 4950 ± 100 µg/g, Ir 10.3 ± 0.5 µg/g, (uncertainties 1?, 68% confidence level), Ge ? 40 µg/g, indicate the IIIAB group.
Iron, IIIAB medium octahedrite, extensive shock, moderate weathering.
Name : Whitecourt Class : Iron IIIAB Region: Alberta, Canada Date : 01 July 2007 TKW : 5372g