The Undyulyung Meteorite

摘要

A meteorite fall was observed by a helicopter crew in flight on September 11, 1986. The meteorite fell to the point bar at the mouth of the Byukkyakh River, the right tributary of the Undyulyung River influent on the right into the Lena River, 80 km upstream the Zhigansk Settlement (Fig. 1). After landing, the pilots immediately found two stones that were still warm, which were distinguished by their black color against the background of the light dolomite pebbles of the point bar. The meteorite had broken into three fragments, two of which were found by the crew. Due to time constraints, the third small fragment was not detected. In 1989, V.V. Korotkov, a member of the helicopter crew, delivered the meteorite samples to the IGABM museum. At present, this meteorite may be studied by permission of the museum staff. The meteorite was called Undyulyung after its locality (φ = 66°8′ N and λ = 124°46′ E). The fall area is located in the Zhigansk administrative district of Yakutia. The total weight of two meteorite samples is 113.4 g. A flattened sample, 65 x 38 x 31 mm in size and 97.7 g in weight, was taken for the investigation (Fig. 2). The second fragment was sent as a sample to the Committee for Meteorites of the Russian Academy of Sciences. The meteorite is enveloped in a black crust of melting. The light gray material of the meteorite is solid and devoid of fractures. The chondritic structure is distinctly observed on polished surfaces and shear planes. Chondrules are 0.3-2.0 mm in size. The uniform impregnation of small metallic particles is seen on the surface of a fresh chip.