Paleoproterozoic stromatolites segosia columnaris and sundosia mira of the eastern part of the Fennoscandian shield: microstructure and 3D modeling

The purpose of this study is to study the microstructure and 3D modeling of Paleoproterozoic stromatolites Segosia columnaris and Sundosia mira in the eastern part of the Fennoscandian shield (Karelian craton). The premise of the study is the extensive paleontological material collected by researchers in the 1950s and 1980s. Modern methods, including SEM analysis, 3D modeling, and the results of Raman spectroscopy are used. As a result of studying the microstructure of stromatolites, possible remnants of cyanobacteria involved in the formation of these structures were identified, which potentially indicated the biogenic origin of the studied samples. The results of Raman spectroscopy obtained by other authors also indicate the biogenic nature of the studied samples. For the first time, images of the spatial shapes of the studied stromatolites were obtained by 3D visualization software, which could be used to refine the classification of stromatolites by morphological features. 3D modeling of stromatolite buildings allowed restoring their original shape.