Drilling to uncover geological mysteries in Gabon

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Geologer studerer berggrunn i Gabon.
Researchers have already conducted some fieldwork around Franceville in Gabon and know where the drilling will take place. Photo: Aivo Lepland, NGU

NGU researchers are part of a strong international research group from 17 countries that has been awarded 1.6 million dollars for an extensive drilling program in the West African country of Gabon. The goal is to deepen understanding of the events that occurred more than over two billion years ago and which led to Earth becoming and oxygen-rich planet.

"We will obtain drill core samples around the city of Franceville in Gabon. In this equatorial country, we find the best-preserved sedimentary rocks formed during this crucial period in Earth's history. The sediments have undergone minimal deformation and metamorphism. Here, we can open a new geological archive," explains senior researcher Aivo Lepland at the Geological Survey of Norway (NGU).

Oxygen-rich atmosphere

He is one of the initiators of the project, which has now been supported with 1.6 million dollars from the International Continental Scientific Drilling Program (ICDP). The institutions and research councils in the 17 participating countries will finance the remaining costs of the estimated 3.2-million-dollar project.

“There are still knowledge gaps to fill before we can better understand how Earth’s surface environments developed between 2.5 and 2 billion years ago. These include questions about what happened when the Earth underwent a complete transformation into an oxygen-rich planet”, Aivo Lepland points out.

“But we will also investigate phosphorus compounds, the deposition of black shale and oil, and not least the formation processes of manganese deposits. Manganese is a critical metal, used among other things in steel. Increased knowledge here can help improve exploration methods for metals”, he says.

Four kilometers of cores

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Kart over Gabon
Gabon is an equatorial country in western Africa. The work will take place around the town of Franceville. Map: Adobe Stock

The project will take place over a long field season in 2025 in Gabon with the help of an international drilling company that has worked extensively with the country’s mining industry. "We have already completed two field trips in the area and know exactly where to go and what we are looking for," says Lepland.

A total of 11 holes will be drilled into the bedrock, extracting four kilometers of drill cores, which will later be sent to NGU. The deepest hole will be 600 meters.

"When we conduct detailed examinations of the cores, we can compile a number of datasets. This gives us knowledge about the processes that led to the emergence of the modern, oxygen-rich Earth system, and thus also about the origin and development of life," Lepland states.

Former chairman of the ICDP, senior researcher Øystein Nordgulen at NGU, said that many good project proposals are submitted each year: "After a thorough evaluation, only outstanding projects receive support following decisions by ICDP's governing bodies," he says.

International Continental Scientific Drilling Program (ICDP)
  • Norway has been a member of the ICDP since 2002. Currently, 23 nations and UNESCO are members of the ICDP. The ICDP projects stimulate international cooperation, involve students and young researchers, and often result in groundbreaking scientific discoveries.
  • The ICDP supports drilling projects of great scientific and societal significance. These projects are important for understanding environmental changes, geohazards, Earth's resources, and the origin and development of life through Earth's history.

Previous experiences from Kola

NGU has also been heavily involved in ICDP projects in the past. For instance, 17 years ago, deep cores were drilled from the Kola Peninsula and Karelia in the project “Fennoscandian Arctic Russia Drilling Early Earth Project” (FAR-DEEP), with senior researcher Aivo Lepland in a leading role. The cores, stored at the National Drilling Core and Sample Center in Løkken, Trøndelag, have garnered significant scientific interest internationally and have resulted in more than 40 publications.

 Øystein Nordgulen emphasizes that it is extremely important for all cores and samples to be registered and stored.

“This ensures that the valuable material is available for future studies by new generations of researchers. FAR-DEEP is recognized as an excellent example of how cores from previous drilling can be used in new research projects where new analytical methods provide even better scientific outcomes from the cores”, says Nordgulen.

70 scientists from 17 countries

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Mann på hengebru
A geological field worker in Gabon on a previous occasion. Here he crosses a suspension bridge to areas where drilling will take place in 2025. Photo: Aivo Lepland

Lepland has long been nurturing the idea of a research project related to Earth's oxygen history and the geological archive in Gabon's subsurface. A year and a half ago, the planning of the new project "Gabon and Oxygenation of Earth - Drilling Early Earth Project" (GOE-DEEP) really gained momentum through a workshop with 50 participants at NGU.

“Thanks to great enthusiasm and the recognition of the project's significant scientific potential, a proposal was developed within a few months”, explains NGU researcher Aivo Lepland.

Initially, the proposal was rejected in the ICDP evaluation. After several rounds of updates and improvements, the project, developed by 70 scientists from 17 countries, was finally accepted in June this year.

The text has been translated from Norwegian to English using ChatGPT and quality assured by members of NGU’s staff.

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