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In the late afternoon (-16:20, Japan Standard Time) of January 7, 1996, a meteorite shower fell around Tsukuba City, Japan, after the appearance of a luminous fireball, a violent detonation and several explosions. Fragments of meteorite covered with fusion crust were discovered in 23 locations within an area of 10km in diameter. The total recovered mass of the Tsukuba meteorite exceeded 800g.
The Tsukuba meteorite is a H (high iron) chondrite breccia composed of light-colored H6 clasts within dark-colored H5 matrix. Most of the recovered fragments, including the largest one weighing 177.5g, consist solely of H6 clast. The H5 matrix contains many chondrules, preserving the original spherical form and quench texture of olivine and orthopyroxene. In contrast, the H6 nature clasts have a holocrystalline granular texture showing intense recrystallization. The polymictic nature is characteristic of the Tsukluba meteorite.
Text: S. Togashi, M. Bunno, Y. Okuyama, N. Kita and T. Sato
