Participants in the AGH UST polar expedition to southern Spitsbergen organised in 2021 by the Orogen Dynamics Team. The photo was taken on the stairs to the Polish Polar Station Hornsund, photo by ODT
The AGH UST-based Orogen Dynamics Team is an international group of geologists who discover traces of processes occurring deep inside the Earth in the mountains. We talked to the team leader, Dr hab. (Eng.) Jarosław Majka, Associate Professor at the Faculty of Geology, Geophysics, and Environmental Protection, about their work methods, history, and new projects.
Mountains rise due to a collision of tectonic plates whose movements and transformations have been occurring for at least a billion years. For example, the Carpathians, the Alps, and Himalayas came to be during the last alpine orogeny that began about 230 million years ago on the interface of the remnants of an old Gondwana continent with Eurasia. The collision of continental plates is preceded by the closure of an ocean. An oceanic plate slides under a continental plate towards the Earth’s mantle.
It is the traces of this process that are so interesting to the scholars of the AGH UST-based Orogen Dynamics Team. ‘Subduction of oceanic and continental plates can reach depths of more than 100 km, where pressures can go higher than 3 GPa and temperatures up to 900–1000 degrees Celsius. Under such conditions, some quite specific mineral phases are born, including diamonds. These diamonds won’t do much in jewellery, but indicate extreme high-pressure conditions. So deep underground, coesite also forms, which is a polymorph of a much more common quartz. It has the same chemical composition but a different crystalline structure’, explains Professor Jarosław Majka.
Partly melted high-pressure rocks in the Richarddalen Complex (North Spitsbergen), photo by J. Majka
Prof. Jarosław Majka and members of the Orogen Dynamics Team during field research in Chamberlindalen (South Spitsbergen), photo by M. Manecki
Dr (Eng.) Karolina Kośmińska during field research on high-pressure rocks in Ellesmere Island (Canada), photo by J. Majka