Fitzwater Pass        42°2’18.2’’N, 120°35’21.9’’W

Oregon, United States

Found: Spring 1974

Classification: Iron meteorite (IIIF)

History: A metallic mass was found by Mr. Paul Albertson at Fitzwater Pass, Oregon. The find location is a grassy area with scattered trees along a mountaintop ~5 km north of the Oregon-California border. One corner of the sample was ground off many years ago by Mr. Albertson, removing perhaps ~2-3 g of material, to reveal a shiny metallic interior. This left a mass of 65.4 g available for study.

Physical characteristics: (A. Ruzicka, Cascadia): The specimen is a small (~4 x 2 x 2 cm) iron meteorite that has a rough, blocky and lineated surface texture, which appears to reflect the internal Widmanstatten structure. It is almost completely covered with a dark brown to black weathering patina.

Petrography: (S. Kissin, LHU; A. Ruzicka, Cascadia): Microscopic examination of cut and etched surfaces show that the meteorite is a coarse octahedrite with bandwidth 1.44 ± 0.29 mm (mean and standard deviation, n = 6 measurements), and kamacite L:W = 3:1 (all widths corrected according to the procedure of Frost, 1965). Microhardness measurements yielded VHN = 202 mean (range 199-203, n = 3) for kamacite, and VHN = 299 mean (range 254-358, n = 3) for taenite. This indicates moderate work hardening. An exterior weathering rind of ~0.5-1 mm thickness containing iron oxide/hydroxide minerals is locally present. Minor sulfide is present.

Geochemistry: (S. Kissin, LHU; A. Ruzicka, Cascadia): INAA was performed according to the methods of Wasson et al. (1998) at Activation Laboratories (Ancaster, Ontario), irradiating polished cubes of ~0.4 g and ~3.2 mm thick. This yielded the following elemental concentrations (all units µg/g except where noted): As (17.9), Au (1.8), Co (5.06 mg/g), Cr (34), Cu (180), Ga (10), Ge (<10), Ir (2.54), Ni (80.7 mg/g), Pt (9.2), Re (0.23), Sb (<20), W (<10). These data suggest a designation of Group IIIF, an uncommon type (with <10 individuals known), although Ga is high compared to other IIIF irons by ~30%, probably owing to analytical error. This is the same group designation as for Klamath Falls, which was found ~78 km to the northwest, raising the possibility that both could have been in the same strewn field. However, the two meteorites are probably not paired, as Klamath Falls has a smaller kamacite bandwidth (0.5 mm), and concentrations for Ir, Pt, and Re that are ~0.002x, ~0.12x, and ~2.8x the values in the new iron.

Classification: Iron, coarse octahedrite (IIIF)

Specimens: A type specimen of 12.4 g is available at Cascadia. The main mass (45.7 g) is held by the finder.