28. Deep Fluid Systems of Fennoscandia Greenstone Belts

A study of the basement of Fennoscandia on magnetic and gravity anomalies has been carried out. There are detected magnetic and density features of the structure of the greenstone belts of the Early Precambrian crust of the Baltic Shield as a result of interpretation of CHAMP and GRACE satellite data and near surface magnetic anomalies. Magnetic and density sections have been constructed through the mega blocks of Fennoscandia with the age of the Earth’s crust ranging from 3.2 to 1.6 billion years that underwent different stages of metasomatosis. There are detected magnetoactive layer in the basement of the Early Precambrian crust (“magnetite zone”) and fluid systems at depths of 12–15 and 25–35 km that are the source of the formation of rich deposits of Fennoscandia greenstone belts. Based on the concept of the distribution of fluid supply flows, there are selected several areas promising for electromagnetic monitoring that can help to detail the features of the basement conductivity of the Baltic Shield.