The New Meteorite Fall of Yanzhuang—A Severely Shocked H6 Chondrite with Black Molten Materials

The new meteorite fall of Yanzhuang — A severely shocked H6 chondrite with black molten materials

At 21:45 hr (Beijing time) on Oct. 31, 1990 the Yanzhuang meteorite hit the ground at the Yanzhuang village, Wenyuan County, Guangdong Province. Several fragments, totalling 3.5 kg, were recovered during the field survey. This meteorite is a rare one of its kind due to its heavily shocked features and thick veins made up of black molten materials. Olivine and low-calcium pyroxene are compositionally homogeneous with Fa=18.59, Fs=16.35 and Wo=1.29. The chemical composition (total Fe=28.0%) and recrystallized texture of the chondritic mass show that the Yanzhuang is an H6 chondrite. The black molten materials occur in the form of blocks (up to 2×3×4 cm in size) and veins (0.1–15 mm in width), and contain a lot of rounded and elliptic FeNi-FeS blobs (up to 6–10 mm in length). The metal in these blobs exhibits distinct dendritic structure characteristic of rapid cooling. Unmolten and molten samples are very similar in chemical composition, fitting well with the average H-chondrites. Partial melting and FeNi/FeS-silicate separation have not been observed in the molten materials of the Yanzhuang. This project was financially supported by the Science Foundation of Guangdong Province.