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本文利用多种地质温度计估算了冲绳海槽浮岩中斑晶矿物的结晶条件。结果表明:灰白色浮岩中的橄榄石、辉石、基性斜长石、磁铁矿等是在大约890℃和大约三十几km深的条件下结晶的。这些矿物之所以存在于SiO2含量高达70％的酸性浮岩中是由于在岩浆喷出地表之前发生了岩浆的混合作用。根据斑晶矿物的结晶深度,推测灰白色浮岩的初始岩浆来自地幔的熔融。
In this paper, a variety of geothermal thermometers were used to estimate the crystallization conditions of the plagioclase minerals in the pontoon of the Okinawa Trough. The results show that olivine, pyroxene, basic plagioclase and magnetite in the gray-white pumice are crystallized at about 890 ℃ and about thirty kilometers in depth. The reason why these minerals exist in acidic pumic rock with SiO2 content as high as 70% is due to the mixing of magma before the magma spews out the surface. According to the crystallization depth of plagioclase minerals, it is speculated that the initial magma of the gray-white pumice comes from the melting of the mantle.