Abstract

The two phase Niz’yavr alkaline pluton is composed of alkali syenite and alkali quartz syenite. The crystallization age of alkali quartz syenite is 2656 ± 3 Ma. According to the isotope data (Rb–Sr, Sm–Nd), the pluton rocks are mantle-derived. The BSE mantle reservoir was the probable source for their melts, like other Neoarchean alkaline plutons in the Kola Province that belong to the association of alkaline gabbro, nepheline syenite, alkaline syenite, and granosyenite. The tantalum–niobium mineralization as pyrochlore identified in the pluton distinguishes the latter from other Neoarchean alkaline plutons in the province.

中文翻译：

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Niz'yavr碱性岩体：年龄，同位素特征和稀有金属矿化

摘要

两相Niz'yavr碱性辉石由碱性正长岩和碱性石英正长岩组成。碱性石英正长岩的结晶年龄为2656±3 Ma。根据同位素数据（Rb–Sr，Sm–Nd），p岩是地幔衍生的。BSE地幔储层可能是其熔体的来源，就像科拉省的其他新古宙碱性岩体一样，属于碱性辉长岩，霞石正长岩，碱性正长岩和花岗质岩。lu体中鉴定为烧绿石的钽铌矿化区将后者与该省其他新古宙碱性p体区分开。