Geologists from St Petersburg University discover that in ancient times a significant part of the clastic material filling the Taymyr Depression was brought from the southwest
Scientists from St Petersburg University have conducted a study of coarse clastic rocks in the Western Taymyr and concluded that more than 300 million years ago these sediments were brought from the southwest, not from the north, as previously thought.
The area of Russia’s largest Arctic peninsula, the Taymyr, is poorly explored from a geological point of view. This is due to the region’s poor accessibility and harsh climate. In particular, the petrographic composition of the Carboniferous and Permian coarse clastic rocks has not been studied in detail before. However, the study of the Taymyr is important in both fundamental and applied terms.
The research findings are published in the journal "Lithosphere (Russia)".
Thus, the analysis of the composition and structure of the Upper Palaeozoic sediments of the Taymyr is of great interest both from the scientific point of view for the reconstruction of the processes of continental mass unification within the supercontinent Pangaea (320-340 Ma), and from the practical point of view. This enables us to understand the peculiarities of the evolution of the continental margins of the Arctic Ocean and solve many important regional problems, such as the formation of oil and gas bearing basins and the giant Taymyr coal-bearing basin, which is a reserve of technological (coking) and thermal coals for future generations.
It should be noted that in the Carboniferous and Permian periods (260-350 Ma), the territory under consideration was radically different from the present day. At that time, it was mostly submerged by the sea; it was a part of the single continent Pangaea; and it was situated in a belt of humid temperate climate, due to which the land was covered with "cordaitic taiga" formed by primitive Holocene trees — cordaites.
The main finding of our work is that the material forming the Carboniferous and Permian coarse clastic rocks of the Western Taymyr was transported by the river for 600 to 1,000 km from the folded structures (mountain systems) of the West Siberian landmass located to the south-west (in modern coordinates), which were formed in the Visean-Serpukhov Age of the Early Carboniferous (320-340 Ma) at the collision of the Eastern European, Kazakhstan and Siberian continental blocks.
Sergey Shishlov, Professor Acting as Head of the Department of Sedimentary Geology at St Petersburg University
This has shown that the Taymyr Foothill Depression received clastic material not only from the Kara landmass, which is now to the north of the Western Taymyr. In the course of their work, the scientists collected 47 samples of gravelites and conglomerates (pebbles and gravel) from different areas of the Taymyr: the Syradasai River, the Tareia River, the Krestianka River, the Pyasina River and Cape Brazhnikov. Large (over 2 mm) fragments of quartzite, acid and basic igneous, metamorphic and sedimentary rocks were analysed and their quantitative ratios were determined.
The equipment of the Resource Centre for X-ray Diffraction Studies of the Research Park of St Petersburg University was used for petrographic description and photography of the samples.
The presented article completes the cycle of publications devoted to the results of the processing of the materials collected during the field work in the Taymyr in the late 20th — early 21st centuries within the framework of the research projects of the All-Russian Geological Institute and the State Geological Survey at the scale of 1:200,000.
St Petersburg University, the oldest university in Russia was founded on 28 January (8 February) 1724. This is the day when Peter the Great issued a decree establishing the University and the Russian Academy of Sciences. Today, St Petersburg University is an internationally recognised centre for education, research and culture. In 2024, St Petersburg University will celebrate its 300th anniversary.
The plan of events during the celebration of the anniversary of the University was approved at the meeting of the Organising Committee for the celebration of St Petersburg University’s 300th anniversary. The meeting was chaired by Dmitry Chernyshenko, Deputy Prime Minister of the Russian Federation. Among the events are: the naming of a minor planet in honour of St Petersburg University; the issuance of bank cards with a special design; the creation of postage stamps dedicated to the history of the oldest university in Russia; and the branding of the aircraft of the Rossiya Airlines to name just a few. Additionally, the University has launched a website dedicated to the upcoming holiday. The website contains information about outstanding University staff, students, and alumni; scientific achievements; and details of preparations for the anniversary.