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在我们致力于获取有关基性岩、高压下岩石形成的矿物/熔体痕量元素的分配信息过程中,我们测定了单斜辉石、斜方辉石、角闪石、云母、歪长石、磷灰石和锆石巨晶,以及它们的寄主玄武岩中稀土和其它痕量元素的丰度。通常由实验分配研究和斑晶/基质测定得到的矿物/熔体分配系数的范围,与巨晶/寄主岩的丰度比范围是一致的。我们的有关Hf、SC、Ta及Th分配数据可供多种估算之用。考虑到相平衡,主要元素的分配和同位素比率表明,在高压下(大概为10—25kb),大多数辉石及角闪石巨晶与它们的寄主岩浆是平衡的。相反,要与它们寄主玄武岩平衡形成云母、歪长石、磷灰石及锆石巨晶,则是不太可能的,而我们推断,它们是从更高程度演化的岩浆中析出的,并且经过混合变为现有的寄主岩浆。因此,巨晶/寄主岩的痕量元素丰度比,不应视为分配系数,而只能当作在高压岩石形成过程中,认识痕量元素分配的向导。有鉴于此,我们假定,巨晶/寄主岩痕量元素丰度数据所表明的,在高压分离过程中,玄武岩体系矿物/熔体的分配系数,与低压分离过程中有效的分配系数,并没有很明显的区别。
In our commitment to obtaining information on the distribution of mineral / melt trace elements associated with rocks of underlying rocks and rocks under high pressure, we determined the clinopyroxene, clinopyroxene, amphibole, mica, crooked feldspar , Apatite and zircon giants, as well as the abundance of rare earths and other trace elements in their host basalts. The range of mineral / melt partition coefficients usually obtained from experimental assignments and plaque / matrix determinations is consistent with the abundance ratio of megacrysts / host rocks. Our distribution of Hf, SC, Ta and Th data is available for a variety of estimates. Considering the phase equilibrium, the distribution of major elements and the isotopic ratios indicate that most pyroxene and amphibole giant crystals are in equilibrium with their host magma at high pressures (about 10-25 kb). On the contrary, it is not possible to balance mica, crooked feldspar, apatite and zircon giants with their host basalts, and we conclude that they are precipitated from a higher degree of magmatic evolution and are mixed For the existing host magma. Therefore, the abundance ratio of trace elements in megacrysts / host rocks should not be considered as a distribution coefficient but only as a guideline for trace element distribution during the formation of high-pressure rocks. In view of this, we assume that the mesogenic / host rock trace element abundance data indicate that during the high pressure separation there is no difference between the mineral / melt partition coefficient of the basalt system and the effective partition coefficient during the low pressure separation Obvious difference.