Age of Dikes in Ancient Tonalites of the Vodlozero Terrane as the Key to Archean Evolution of Basic Magmatism of the Fennoscandian Shield

摘要

The Fenno-Karelian province (granite-greenstone terrane) is the largest and best studied fragment of the Archean crust on the Fennoscandian shield. It consists of terranes that differ in structure, crust age, and formation sequence of the rock complexes [1]. The Vodlozero craton that occupies the eastern part of the shield holds a special place among them [1]. It is characterized by the wide development of Mesoarchean (>3.1 Ga) rocks with an Nd model age of 3.3-3.4 Ga and can be considered as the oldest core of the Fennoscandian shield [2].