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Vol. 1 (1998 year), No. 3

Fedotov Zh.A., Amelin Yu.V.
The Postsvecofennic Dykes of Kola Region Dolerites: Craton Magmatism Dual Nature

The results of petrological study of unmetamorphised young dolerite dykes are presented. They are forming four isolated swarms. Probable evolution mechanisms of the magmatic melts which determine the dolerites composition diversity are considered. The Sm-Nd age estimation of three dykes are given. The available estimates make able the following conclusion: practically the whole postsvecofennic magmatism coincides with the Palaeosoic period. On the Baltic Shield, as a whole, Phanerozoic appearances of the magmatism are well known in the south-western part of Norway and Sweden, as well as in the Kola Region, it means - on the periphery of East-European Platform, whereas the Proterozoic dykes are developed in the whole shield area. It is obvious, that Phanerozoic magmatism of the Baltic Shield is related to the reflected tectonic-magmatic activity of the passive plate, opposite to the Proterozoic one, being characteristic for the final craton evolution stage of the shield crust itself.

(in Russian, стр.9, fig. 6, tables. 3, ref 29, MS Word 95, MS Word 95 575 Kb)