This was reported by the press service of the scientific center. As Alexandra Stepanova, Deputy Director of the Institute of Geology, noted at a meeting of the Academic Council, it is difficult to study the early large igneous provinces: they have been strongly transformed and fragmented for more than two billion years. They can be reconstructed by studying mafic dikes, narrow and elongated bodies filled with solidified melt, which rose along cracks and faults to the Earth’s surface billions of years ago.
And although scientists from different countries have done a lot of work, which made it possible to form a dike barcode for the whole world, to evaluate the sequence of formation of large igneous provinces and their relationship with the formation of continents, new data have also been obtained. Some issues remain debatable, including the location of the Fennoscandian Shield among other Precambrian continents.
Over the past few years, researchers in Karelia have obtained important data on a number of objects in the White Sea, Karelian, Kola and Murmansk tectonic provinces. Each object was studied by a set of methods, which made it possible to obtain the characteristics of primary melts and evaluate the conditions for their formation.
The similarity in the evolution of magmatism in all tectonic provinces of the Fennoscandian Shield indicates that they belonged to the same lithospheric block and were part of the ancient Kenorland supercontinent. It formed about 2.7 billion years ago and existed for at least 2.4 billion years. Unlike age, the configuration of the continent has not yet been finally determined and is the subject of discussion among scientists.