Natural Elements, NRCan's Monthly Newsletter

The New Geological Map of the Arctic: Canada Leads the Way

Christopher Harrison, GSC-Calgary (left, pointing at map) discussing ways of portraying the geology of the Arctic Ocean with representatives from the U.S., Russia and Denmark. St. Petersburg, Russia, March 2008

At 1.5 metres in diameter, the recently released Geological Map of the Arctic is the largest and perhaps the most intricate map of its kind ever produced in the 168-year history of Natural Resources Canada’s (NRCan’s) Geological Survey of Canada (GSC).

Part of an international atlas of geoscience maps of the circumpolar Arctic, the 1:5 million scale Geological Map of the Arctic and its related database were developed by GSC teams based in Calgary and Ottawa with the active participation of scientific and technical staff from the geological surveys of Russia, the United States, Norway, Sweden and Denmark. Begun in February 2006 and carried forward at polar map workshops in Canada, Alaska and Russia, the final version of the Geological Map of the Arctic was published in paper copy and electronic forms in November 2008 as part of the International Polar Year.

With its many details and those of the database that accompanies it, the Geological Map of the Arctic is a rich resource that will have many practical uses. By showing how the ages and types of rock across the Arctic compare with ages and types of rock where, for example, oil, gas and metal ore have already been found, the map will help guide exploration and development for new deposits of these or other resources.

The technical challenges involved in a project of this scale and scope — converting numerous paper copy regional maps to digital, applying a common database standard to existing digital products, creating a base topographic map to carry the geological features — were many.

Marc St-Onge, GSC-Ottawa (sitting centre) discussing onshore map unit attributes with Russian colleagues. St. Petersburg, March 2008

“Issues to resolve included the proper registration of geology to shorelines and ice caps and the production of seamless registered layers for drainage and bathymetric contours,” says Marc St-Onge, a senior research scientist with the GSC.

Hundreds of source maps had to be simplified from a wide variety of scales. Methods had to be found for referencing published and unpublished sources and for acknowledging the contributions of the project’s numerous participants, both minor and major.

These challenges, however, were relatively straightforward compared to those raised by the fundamental questions that all cartographers must ask: What should the map include? What should it exclude? How should it present its details?

“For starters, we all had to agree on what constitutes a geology map,” says Marc. “Some countries needed convincing that rock type could be displayed at 1:5 million scale. Others insisted on including surface materials, such as sand, gravel and clay, rather than bedrock. Another country would have been happy if the map just showed the age of rock units, period.”

Agreement among the international partners on several other features had to be found, including the importance of plate tectonic features; the standardization of terms for geological time periods; and the definition of map units in deep ocean basins, a matter of great potential importance in terms of current and future geopolitical considerations. And of course interpretive inconsistencies on map boundaries between and within countries had to be resolved.

The Geological Map of the Arctic also has a substantial, newly developed infrastructure. It is supported by the first complete, seamless, spatial database of onshore and offshore bedrock geology for approximately half of Russia and Canada, including most of Canada’s three territories, most of Alaska and Scandinavia and the entire Arctic offshore north of 60° latitude. Included in the database — and also portrayed, in simplified form, on the paper copy version of the map — are tens of thousands of spatial objects. These features include: individual geology units coded for composition, age, environment of formation and plate tectonic domain; geological contacts, faults and oceanic spreading ridges; and volcanoes, meteor impact structures, salt and gypsum extrusions and selected point data such as for kimberlites, the rocks that carry diamonds up from the depths of the earth.

A free copy of the Geological Map of the Arctic can be downloaded in various electronic formats from NRCan’s MIRAGE (Map Image Rendering Database for Geoscience) web site, which provides a digital image library of more than 10,000 NRCan maps. A wide range of related electronic databases is also available free of charge from NRCan’s Geoscience Data Repository.