The first living organisms to master photosynthesis were cyanobacteria. Acting together with other microorganisms, they formed cyanobacterial mats, which ultimately turned into real oxygen factories. These mats are made up of alternating layers of dead bacteria and carbonaceous sediment. Live bacteria are on the surface of the top layer. The mat grows thicker over time, the bottom layers get compressed and dewatered, becoming gradually fossilized and buried in the sediment. These fossils are called stromatolites (Gr. layered rock). There are not so many places in Russia where you can find them, but Karelia is lucky: such fossils found in our regions are around 2 billion years old. These artifacts of ancient life on Earth have been discovered in rock outcrops on the shores and islands of Lake Sundozero, Kondopoga District.

Karelian stromatolites have been under research since the 1950s: localities with these structures are known from all over Karelia, vast paleontological material has been collected, new genera and species have been described. Fossil specimens are on display in the Museum of Precambrian Geology of KarRC RAS. New technologies and methods now available permit looking at this paleontological phenomenon from a new perspective. Junior Researcher of the Institute of Geology KarRC RAS Andrey Lyutikov was among the first to apply 3D modeling for its visualization.


Andrey Lyutikov working in the field. Using a geologist’s hammer when sampling stromatolites is an exception – normally, scientists try to keep the object intact, searching for specimens among rock debris instead.

To make the reconstructions, the scientist first cuts rocks into thin, 5-7 mm, slices and polishes them if needed. Each cross-section is photographed at high precision and then the images are treated in a graphic editor and superimposed one on another. The 3D model is created using Blender software.

– Previously, stereoscopic images of stromatolites were produced manually by the graphic dissection method: a specimen was also sliced, the stromatolitic layers were drawn on tracing paper, and the sections were stacked up. The whole process took over 20 hours. Our simulation is ready within 5 hours, and its accuracy and functionality are by far higher, – shared Andrey Lyutikov.

The scientist has made about a dozen 3D models of stromatolites from the eastern Baltic Shield. E.g., for Segosia columnaris (from Lake Segozero) and Sundosia mira (from Sundozero). The microbialite dataset for Karelia comprises some 50 species in total. Andrey’s plan is to make a model for each species and to expand the dataset.



Polished sections (top) versus 3D models (bottom) for Sundosia mira (А) and Segosia columnatis (B)

Three-dimensional models do more than just reveal what stromatolite structures look like freed from their surrounding rock. Firstly, the technology helps create a generalized model of the give stromatolite species based on the analysis of several samples. Secondly, the model standardizes the object, allowing researchers to visualize it consistently even without a physical specimen on hand. Previously, scientists had to rely on descriptions, drawings, or photographs. Thirdly, 3D models can help refine the existing (though not yet internationally approved) stromatolite classification based on morphological features. 3D models offer the possibility to take a close look at the finest details and structural characteristics of stromatolite formations, which are crucial for species descriptions. This, in turn, could serve as a tool for paleo-reconstructing the environmental conditions at the time these structures formed.

– Stromatolite structures differ in shape depending on the waterbody’s hydrodynamic regime. E.g., Segosia (L. Segozero) and Sundosia (L. Sundozero) are columnar stromatolites. The structures deposited by Sundosia exhibit low-angle lamination arches and branching columns. In Segosia stromatolites, on the other hand, arches are sharp, columns much smaller and packed closely together. This indicates the action of currents and waves at both locations but greater dynamics in the Segozero area. Studying the sequence in its entirety, we can discover how the hydrodynamical regime in the basin was changing two billion years ago, – the geologist remarked.



Last but not least, such visualization is leveraged in science popularization.

– Dinosaurs and mammoths have long been reconstructed. They even visualize the "Cambrian life," such as trilobites and other Paleozoic creatures. So I thought, why not demonstrate stromatolites? After all, they are some of the oldest evidence of life on Earth, – shares Andrey Lyutikov.

At the same time, scientists believe that nowadays stromatolites should not only be popularized but also protected. Being easily accessible and valuable, Karelian fossils have become a tempting target for collectors and just profit-seekers. This year, the Sundozero Sequence Nature Monument was given the protected area status.

– Our stromatolites are unique, especially for Russia. Karelia contains a majority of known Paleoproterozoic stromatolite formations. They must be protected and preserved. Losing such a monument of Earth's history would be an irreparable loss, - proclaims the scientist.


KarRC RAS Director General Olga Bakhmet and Junior Researcher of IG KarRC RAS Andrey Lyutikov at award ceremony of Scientific Articles Contest. Photo by V. Shvetsova / KarRC RAS

The results of Andrey Lyutikov’s endeavors were published in the Vestnik of Geosciences Journal. The young scientist is a winner of the scientific articles contest 2024, in the Earth Sciences section. The researcher is currently working on his doctoral thesis on microbialites (a generic group of ancient bacterial life forms, which includes stromatolites) of the eastern Baltic Shield.

Photos from Andrey Lyutikov’s archives / IG KarRC RAS