Geochemists from St Petersburg University are the first in Russia to date an underwater mineral from the largest basin in the eastern Arctic

The eastern Arctic is one of the least explored geological regions on Earth. It includes the Amerasian Basin of the Arctic Ocean, which extends from the Canadian Arctic Islands to the East Siberian Sea and from Alaska to the Lomonosov Ridge.

The findings of the research supported by a grant from the Russian Science Foundation are published in the scientific journal Geochronology.

In 2017, scientists from St Petersburg University obtained samples of rare rocks from the slopes of the Chukchi Plateau, a subsea ridge in the Arctic Ocean. The geologists discovered that the samples contained rare hydrothermal ferromanganese (Fe-Mn) mineralisation.

Mineralisation refers to a change in chemical composition caused by various factors such as water, temperature, and pressure. This process can involve the following: the alteration of the structure of existing minerals; the formation of new minerals; and even the complete transformation of a rock into a different type. Thanks to this, the geologists from St Petersburg University were able to determine the age of the sample, contributing to a better understanding of the geological development of this region.

"Due to the lack of classical geochronometric markers for this type of underwater formation, we applied the (U, Th) / He goethite dating method for the first time to a sample of this origin. This work was carried out using original technology on a set of instruments developed specifically for determining the (U, Th) / He age of pyrite," said Olga Yakubovich, Professor in the Department of Geochemistry at St Petersburg University, Research Associate in the Laboratory of Isotope Geology at the Institute of Precambrian Geology and Geochronology of the Russian Academy of Sciences, and laureate of the Presidential Prize of the Russian Federation in Science and Innovation for Young Scientists.

In the year of the 300^th anniversary of St Petersburg University, Olga Yakubovich won the annual Presidential Prize in Science and Innovation for Young Scientists for her work on the development and improvement of methods for determining the age of minerals by helium concentration. The team of scientists she led was the first in the world to demonstrate that this approach could be used to accurately determine the time of formation of platinum, gold, and pyrite. Since pyrite is a mineral that occurs in all types of deposits, the method developed by the St Petersburg University scientist makes it possible to quickly and inexpensively determine whether a particular natural site is promising for the discovery of large deposits of valuable metals.

Olga Yakubovich explained that the helium dating method has previously been used for goethite. This mineral typically forms in weathering crusts under near-surface conditions, which helps preserve helium used for dating. However, as the geologist noted, the task was particularly challenging in this case because the sample under investigation was formed through an underwater hydrothermal process — a rare phenomenon in the eastern Arctic.

Furthermore, only four scientific laboratories worldwide are currently capable of dating goethite. By adapting the pyrite-based rock age determination technology for goethite, the scientists from St Petersburg University became the fifth research team in the world, and the first in Russia, to achieve this task at a high level.

The research was carried out within the framework of the project supported by a grant from the Russian Science Foundation (project No 22-77-10088). St Petersburg University has been among the leading recipients of grants from the Russian Science Foundation in recent years. In 2022 and 2023, the University was the leader in the number of grants from the Russian Science Foundation: in 2022, St Petersburg University researchers received 112 grants, which is 5.5% of the total number of winning projects and the largest number of grants for one organisation. In 2023, the University maintained its leadership in this contest of the Russian Science Foundation: scholars from St Petersburg University received 70 grants, which is 5% of the total number of winning projects. Additionally, 41 research projects at St Petersburg University were supported by the Russian Science Foundation at the end of 2024.

Using this approach, the scientists from St Petersburg University were able to determine that the rocks underwent mineralisation during the Neogene period (5–9 million years ago). This marks the first evidence of active tectonic processes in the eastern Arctic during that time. This finding can refine geological models of the region’s development and, consequently, help adjust the strategy for the prospecting and exploration of hydrocarbon deposits on the Arctic shelf of the Russian Federation.

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 celebrated its 300^th 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 300^th 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; and the branding of the aircraft of the Rossiya Airlines to name just a few. To mark the 300^th anniversary of St Petersburg University, a postage stamp depicting the Twelve Collegia building and the monument to Count Sergey Uvarov was issued. Also, a Soyuz rocket bearing the symbols of the University was launched from the Baikonur Cosmodrome.

By the decision of the Governor of St Petersburg Alexander Beglov, 2024 was a year of the 300^th anniversary of St Petersburg University in St Petersburg. On the day of the University’s 300th anniversary torches were lit on the Rostral Columns on the Spit of Vasilyevsky Island. St Petersburg University flags were raised on the Palace Bridge. The city public transport was decorated with the University’s symbols. During St Petersburg’s City Day celebrations in May 2024, St Petersburg University acted as a participating venue. Additionally, the University launched a website dedicated to the anniversary. The website contains information about outstanding University staff, students, and alumni; scientific achievements; and details of events held as part of the celebration of the 300^th anniversary of the University.