| Summary: | Archean cratons hold information of the early crustal development of the Earth, in conditions much different than the ones that exist today. Archean cratons consist of felsic plutonic rocks and greenstone belts. These belts are a useful tool for the understanding of the development of the early geological processes that shaped the Earth. There has been a variety of suggestions regarding the origin and geodynamic conditions that formed the Archean greenstone belts and there are several possible geotectonic scenarios that could form them. This thesis focuses on the Takanen greenstone belt found in the Karelia province in the Fennoscandian shield. The main objective of this study is to constrain the age of the greenstone belt, as well as to classify and group the formations found in it and compare it with its neighbouring, and much larger, Suomussalmi-Kuhmo-Tipasjärvi greenstone belt system - the biggest complex of its kind in the Karelian craton. A diamond drilling profile across the Takanen belt has been sampled. The various rocks found in the belt are divided into 5 groups based on their thin-section petrography and major and trace element geochemistry, outlining the general stratigraphy of the belt. There are also whole rock analyses that help to obtain major and trace element geochemical data for multiple samples from different locations throughout the belt. There are 3 calc-alkaline units (CALC1, CALC2, CALC3, named after their predominantly calc-alkaline nature) that include felsic, to intermediate volcanic/volcanosedimentary rocks and 2 units that consist of channelized komatiitic lavas and tholeiitic basalts (KOMBAS, named after the komatiites and basalts of the unit), olivine/olivine-pyroxene cumulates and high-Mg to tholeiitic basalts (OLIAD, named after the abundance of olivine adcumulates). The CALC1 unit is found lowest in the stratigraphy of the area and bares the oldest age of 2.95 Ga, while CALC3, which is the youngest formation of the belt, gives an age of 2.7 Ga. There is a direct correlation ...
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