Abstract

The results of geochemical studies of Paleoproterozoic volcanic rocks in the structure of the Polmak–Pechenga–Imandra–Varzuga belt of the northeastern part of the Fennoscandian Shield are presented. Taking into account new geochronological data, the volcanic series are correlated with subvolcanic and intrusive rocks of the Murmansk and Kola–Norwegian terranes. The comparative analysis of sections of volcanic rocks of the Imandra–Varzuga and Pechenga structures indicate asynchronous evolution of these fragments of the belt in a range of 2.51–2.40 Ga and a significant time gap (probably, >300 m.y.) in evolution of both the Imandra–Varzuga and Pechenga structures. The geochemical evidence is provided for the cyclic plume-lithospheric interaction during magmatism of the Sumian–Sariolian period, which shows that basic melts mostly generated from facies of spinel lherzolites exhibit features of significant crustal contamination as a result of their interaction with rocks of the Archean basement.

中文翻译：

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古元古代（2.51–2.40 Ga）东北芬诺斯坎迪亚的火成岩省：火山岩的地球化学及其与侵入复合体的关系

摘要

提出了芬诺斯堪的亚盾构东北部的Polmak-Pechenga-Imandra-Varzuga带结构中的古元古代火山岩的地球化学研究结果。考虑到新的年代学数据，火山序列与摩尔曼斯克和科拉－挪威地层的次火山岩和侵入岩相关。对Imandra–Varzuga和Pechenga构造的火山岩剖面进行的比较分析表明，这些带的碎片在2.51–2.40 Ga范围内异步演化，并且两个演化都存在明显的时间间隔（可能> 300 my）。 Imandra–Varzuga和Pechenga结构。为苏木-Sariolian期岩浆作用期间的周期性羽-石圈相互作用提供了地球化学证据，