NSU Researchers Prove: Ancient Arctida Existed

Scholars fr om NSU and the Trofimuk Institute of Petroleum Geology and geophysics (SB RAS) have proved with facts and figures the existence of a paleocontinent named Arctida, which formed around one billion years ago, split apart and then came back together again.

The conclusions derived are based on studying the ancient geomagnetic field. According to previous hypothesis, there might have been an ancient continent located at the top of the world, but scientists did not have numerical data to verify it. According to the results of paleomagnetic studies, our geologists concluded that not only the ancient continent existed, but it also split apart and came back together twice rather than once as was previously thought.

The results were published in a prestigious journal Precambrian Research. The publication Arctida between Rodinia and Pangea is a result of collaboration between Dmitry Metelkin, Valery Vernikovsky and Nikolay Matushkin, who work at the Geology and Geophysics Department at NSU.

Professor Dmitry Metelkin shares some information about the research. ‘Historically, presently separate fragments of the modern Arctic shelf used to form a continent which split apart and shaped the modern Arctic. These fragments drifted and joined the northern edge of modern Eurasia. We aimed at reconstructing the main evolutionary stages and mechanisms of the structure of Arctida from the Early Neoproterozoic to the Mesozoic by studying the role of the continental blocks of the Arctic in the global drift of lithospheric plates.’

The study is based on paleomagnetic data from over 20 years of Arctic explorations, mainly within the Arctic Archipelago. The method used helps to identify the location of ancient blocks of Arctic sialic crust. Such a reconstruction is possible due to features of the ancient paleomagnetic field “recorded” in ancient rocks at their birth. Paleomagnetic characteristics depending directly on the block location, it is possible to identify this location quite accurately, to within a few degrees.

‘From our model we propose the existence of two (!) Arctic subcontinents in the Neoproterozoic–Paleozoic history of the Earth rather than one continent, as it was previously regarded. Arctida-I, which formed a billion years ago, was a collage of ancient blocks of Arctic sialic crust within Rodinia in the junction zone between the Laurentia, Siberia and Baltica cratons. The supercontinent of Rodinia broke up about 750 mln years ago. Arctida-I in its turn formed a number of small continental plates drifting mainly at the periphery of the Siberian paleocontinent, which was then in a subequatorial position. The rebirth if Arctida occurred at the Paleozoic-Mesozoic lim it about 250 mln years ago. It was connected with the assembly of a new supercontinent Pangea. Arctida-II consisted essentially of the same elements as Arctida-I, but their configuration changed, and they happened to form the periphery of modern Eurasia.’

The present-day remains of the ancient continent include Frantz Josef Land Archipelago, Svalbard or Spitsbergen Archipelago, the Kara Sea shelf with archipelagos in Severnaya Zemlya and the north coast of the Taimyr Peninsula, the New Siberian Islands, the East Siberian Sea and the Chukchi Sea shelves together with the continental territories of Alaska and Chukotka, and some islands of North America including Ellesmere Island and some islands near Greenland.