Russian basement hides the riddle of the Earth’s oxygen

“This is a geological dream coming true,” says Victor Melezhik. For many years, this Norwegian-Russian geologist has been seeking a chance to study the depths of the Russian basement.

Now he’s getting started, along with his colleague at NGU, Aivo Lepland.

Geological riddles

Six million NOK from the International Continental Drilling Programme (ICDP) are ready to be used to solve old geological riddles on the Kola Peninsula and the banks of Lake Onega in Karelia. Sediments and lavas dating from 2.5 to 2 billion years ago conceal valuable information, first and foremost about the oxygen content in the atmosphere which increased at that time.

”What really happened when the world got a more oxygen-rich atmosphere about 2.3 billion years ago? Was it because oxygen-producing life forms expanded? Or did geological evolution cause the Earth’s surface to become gradually more oxic? That could have led to the production of oxygen exceeding its uptake, resulting in the excess oxygen accumulating in the atmosphere,” Aivo Lepland suggests.

“We want to learn more about the fundamental processes behind the increase in oxygen. How long did it take and how did the various events interact and influence one another?” Victor Melezhik adds.

Oxygen and oil

The increase of oxygen in the atmosphere marked the very beginning of the ”modern Earth” as it functions today. The rocks from the birth of the ”modern Earth” have isotopic and chemical signatures that contain proof of dramatic events like the break-up of continents, volcanism and repeated global ice ages or the ”Snowball Earth”.

“Increased biological production in the oceans led to deposition of sediments rich in plant remains. The first big oil reservoirs were also formed then. The asphalt-like oil that became fossilised long ago clearly shows that oil formed early in Earth history. Knowledge of the processes that formed this ancient oil may in turn point the way towards new plays and exploration techniques,” the geologists tell me.

International cooperation

The drilling in the Fennoscandian Arctic Russia – Drilling Early Earth Project (FAR-DEEP) will take place from June to November this year. Fifteen holes from 100 to 500 metres deep will be drilled at Pechenga and Imandra on the Kola Peninsula and in Karelia, further south.

The actual research begins when Victor Melezhik and Aivo Lepland are back in Norway with 4000 metres of drill cores towards the end of the year. Scientists from as many as 15 nations will come to Trondheim then to sample the cores. Universities around the world have already promised more than 30 million NOK for this research, which will last five years.

”At the moment, only the recently started Centre for Geobiology at the University of Bergen has joined the project, but we want cooperation and contact with both the petroleum industry and other research institutions in Norway,” says Aivo Lepland.

”We’ll also be building up a good, readily available archive of the material and the results so that everyone will be able to study the core samples, which we expect will be the best rock archive from the time when our oxygen-rich Earth evolved,” Victor A. Melezhik and Aivo Lepland say.

By Gudmund Løvø