The cosmic spherules have been found from heavy fraction of placer near the Luobu ultramafic rock body in Zedang, Xizang. According to their charac- teristics of surficial texture and the compositions, the spherules can be divid- ed into two groups: silicate and iron. They are similar to those from present- day deep-sea, sediments and ancient strata. The iron spherules are characterized by distinctive surficial textures, such as wrinkled, air-etched, break-cracked and buttonlike. Most of the iron spheru- les discovered in this area are dominantly globular, black in colour and with metallic luster. They possess black fusion crust and weak megnetism. The dia- meters of spherule range from 0.05 to 1 mm. Some particles are polylayered in cross section. The outmost fusion crust is composed of magnetite; the inte- rior of wllstite. The core is of Ni-Fe metal. The silicate spherules are less abundant. They are also globular with smooth surface of weak magnetism, and may be divided into two types:colourless- transparent and brown-subtransparent. We suggest that most of the iron and silicate spherules might be the drop- lets sprayed from the fusion crust of a meteorite as it ablates by grazing in atmosphere, or these spherules would have been produced by extrusion of the lunar volcano.
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梁日暄,宛传永,王炳熙,彭佑华,1982,西藏泽当地区的宇宙尘[J].岩石矿物学杂志,1(3):1~8.,1982,Cosmic Spherules from Zedang, Xizang (Tibet) in China[J]. Acta Petrologica et Mineralogica,1(3):1~8.