A study from northern Alaska could rewrite the history of the Arctic

May 28, 2019 – Parts of the mountain range of Brooks, Alaska, have probably been transported from Greenland and part of the Canadian Arctic much further east, according to a series of 39; studies conducted by Dartmouth detailing more than 300 million years of geological history of the Arctic.

The discovery updates the geological evolution of the Arctic Ocean and could help revise forecasts regarding Arctic oil, gas and mining wealth.

By explaining the formation of the Arctic Ocean in the Western Hemisphere – known as the Amerbasan Basin – the research provides more clues about the geological history of this rapidly changing region.

"This is undoubtedly the most important place for the United States from the standpoint of Arctic economic development," said Justin Strauss, assistant professor of Earth Sciences at Dartmouth. "The geology of this region, directly related to its ancient history, will allow us to revise our knowledge of Arctic natural resources."

The current pattern of Arctic Ocean formation along the US and Canadian border regions explains in detail how seismic activity, called a fault, has pushed Alaska to turn away from a band from the western islands of the Canadian Arctic from about 125 million years ago.

In this original "rotation" scenario, parts of the Brooks chain should perfectly match the Canadian Banks and Victoria Islands, which are approximately 30,000 km away.

However, after nearly 10 years of studying exposed rocks in the region, studies in Dartmouth show that the region actually contains rocks that can be as far as 1,200 miles to the east. The results have recently been published in a Special Papers series of the Geological Society of America.

"The geology of northeastern Brooks Range does not correspond to anything we have studied in the neighboring region of North America," said Strauss, research director of the study. "This complicates the previous models of opening this great ocean basin."

Further confirming the results, the researchers in the study area detected signs of mountain formation processes that would not have occurred near the current position of the Brooks Range. This collision of ancient land masses dating back 400 to 450 million years is more closely associated with tectonic activity in the eastern Arctic.

The team believes that the region has been formed by a combination of activities, including the action of a large slip fault system, similar to California's San Andreas Fault, which carried part of the current chain from Brooks of Greenland to Western Canada Arctic Islands.

A smaller-scale rotation of the more west-facing land mass that was previously recorded could complete the explanation of how North Alaska was transported to its current location.

"Relationships on the northwestern margin of North America have long been misunderstood and poorly documented," said Bill McClelland, professor of land and environmental studies at the University of Michigan. 39, University of Iowa and co-investigator of the study. "The results of these studies have significantly improved our understanding of the tectonic processes that formed the Arctic margin of North America and will help advance the new frontiers of research."

"Because of its remoteness, the North Slope of Alaska and Yukon has yet seen only a few studies," said co-investigator Maurice Colpron, a Yukon Geological Survey scientist. "Understanding the region with absolute certainty will require many more years of hard work, but these research results greatly improve our knowledge of the region."

As the Arctic continues to open up to the development of oil, gas and mineral resources, this new understanding of the region's history could change expectations about the region's resource wealth.

According to the United States Geological Survey, about 6% of the world's oil and 25% of natural gas is in the Arctic. The area studied by the team is in the Arctic National Wildlife Refuge, an area that some would like to open for oil drilling.

In addition to changing the outlook for resource wealth and its location in the Arctic, research may have an impact on how countries claim these resources. The United States, Russia, Canada and other Arctic countries are scrambling to establish themselves in the region.

"If countries want to make legal claims based on geology or geophysics, they must take into account these much older boundaries that we emphasize.Governments will have to face the complexities of geological meeting policy," Strauss said.

Magnetic surveys allow researchers to understand how the Eurasian basin of the Arctic formed in Europe and the western regions of Asia, but these same data are not as easy to interpret for the amerasian basin over North America.

The research, funded by the National Science Foundation, is based on the existence of a major fault system in northern North America, which has not yet been fully mapped.

"The Arctic Ocean region is always baffling researchers, and it's one of the last great ocean basins on the planet that we simply do not understand," said Strauss.

In future studies, the research team will focus on the Yukon and Ellesmere Island, Canada, in order to search for key failure systems. The research will trace hundreds of millions of years of geological evolution in order to explore in more detail the origin of this part of Alaska and the reasons for its landing.

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