Orotukan        62°9’8" N, 151°16’15" E

Magadanskaya oblast’, Russia

Find: Aug 2022

Classification: Iron meteorite (ungrouped)

History: The meteorite was found at the foot of the left slope of the river valley of the downstream of the Strelka Creek, the left tributary of the Orotukan River.

Petrography: (Ksenia A. Konovalova, FMMR). Medium-grained octahedrite having a well-developed Widmanstätten pattern with 0.7-1.1 mm kamacite bands. Thin lamellae of taenite in kamacite have sizes up to 70 µm. Large schreibersite coarse grained inclusion (1-2 mm) is occured.

Geochemistry: Mineral composition and Geochemistry: EDS analyses (Atali Agakhanov, Ksenia Konovalova, FMMR). Kamacite (in wt. % n = 2) : Fe - 89.45, Ni - 7.6, Co - 0.74, taenite (in wt. %, n = 7): Fe - 62.07, Ni - 35.2, Co - 0.37, schreibersite (in wt.%, n=6): Fe - 44.88, Ni - 38.04, Co - 0.24, P - 14.49. Bulk composition of the meteorite (ICP-MS, V.K. Karandashev, IPTM RAS):Ni = 8.61; Co = 0.45 (both in wt%);Cr =154, Cu = 127, Ga = 39.4, Ge = 54.9, Mo = 17.2, Ru = 23.6, Rh = 3.3 Pd = 3.7, W = 2.5, Re = 1.5, Os = 20.2, Ir = 13.3, Pt = 26.1, Au = 0.82 (all in µg/g). 

Classification: (Kseniya A. Konovalova, FMMR). Iron, Ungrouped. Based on Ga, Ge content iron is reminiscent IAB and IID meteorites. Ni (8.61 wt.%) and Co (0.45 wt.%) as similar to IAB complex group, Au (0.82 µg/g) is lower than that of IAB irons, and Ge (54.9 µg/g) is lower than that of IID, irons so this sample is ungrouped.

Specimens: ZOLOTOY IRIS LLC (Magadan, Russia) holds main mass, 51 g - FMMR