The results of geochronological and petrological studies of the largest mafic dyke in the northern part of the Fennoscandian Shield, called the Great Dyke of the Kola Peninsula (GDK), are presented. According to U-Pb D-TIMS baddeleyite dating, the GDK crystallization age is 2680 ± 6 Ma. The age of host granites is 2.75–2.72 Ga (U-Pb, zircon, SHRIMP-II). The dyke has a simple internal structure with no signs of multistage melt injection. It comprises equigranular and plagioclase-porphyritic dolerites and gabbro that are amphibolitized to varying degrees. All rocks are low-Mg (Mg# less than 0.37) with low concentrations of Cr and Ni, and were derived through differentiation of more primitive melts. The analysis of geochemical and Sr-Nd isotopic data suggests that GDK melts could be formed by mixing of two types of mantle melts: depleted asthenospheric melt and enriched melt formed via melting of a lithospheric mantle. The weakly fractionated HREE patterns indicate that primary GDK melts originated at shallow (<60 km) depths outside the garnet stability field. The generation and injection of melts of the Neoarchean GDK occurred immediately after large-scale granitic magmatism and main crustal growth event in the Murmansk Craton and marked the cratonization of the continental lithosphere in the northeastern part of the Fennoscandian Shield.

介绍了 Fennoscandian Shield 北部最大的镁铁质堤坝（称为科拉半岛大堤坝 (GDK)）的地质年代学和岩石学研究结果。根据 U-Pb D-TIMS 斜锆石测年，GDK 结晶年龄为 2680 ± 6 Ma。寄主花岗岩的年龄为 2.75–2.72 Ga（U-Pb、锆石、SHRIMP-II）。堤坝内部结构简单，没有多级熔体注入的迹象。它由不同程度角闪岩化的等粒状和斜长斑状辉长岩和辉长岩组成。所有岩石都是低镁（Mg# 小于 0.37），具有低浓度的 Cr 和 Ni，并且是通过更原始的熔体分化而来的。地球化学和 Sr-Nd 同位素数据分析表明，GDK 熔体可能由两种类型的地幔熔体混合形成：通过岩石圈地幔的熔化形成贫软流圈熔体和富集熔体。弱分馏的 HREE 模式表明，主要的 GDK 熔体起源于石榴石稳定场外的浅层（<60 公里）深度。新太古代GDK熔体的产生和注入紧接在摩尔曼斯克克拉通大规模花岗岩岩浆作用和主要地壳生长事件之后，标志着芬诺斯堪地亚地盾东北部大陆岩石圈的克拉通化。