National Identity in Stone: Finland’s Ancient Crust Meets Canada’s Hadean Record

The Earth began to form 4.7 billion years ago, when planetesimals—formed from material left over from the birth of the Sun—started to attract particles from the surrounding space and gradually gave rise to planets. This process eventually led, around 4.6 billion years ago, to the birth of the rocky planet on which I am writing this text.

This information was once taught to Finns of my generation. At the same time, we were told—in a spirit of patriotic pride—that Finland’s bedrock is extremely old, up to three billion years in age, though this is unlikely to be emphasized in the same way to today’s youth, who are more often guided to see themselves as global citizens.

This remains true, as the oldest known rock in Finland is about 3.5 billion years old. It is located slightly north of Finland’s geographical center, in the municipality of Pudasjärvi.

There is very little direct information about the Earth’s earliest crust, because rocks and minerals from the Hadean eon (>4.03 billion years old) are extremely rare. Even so, the age of the rock material in Pudasjärvi pales in comparison to that of the Canadian bedrock.

This is because, according to recent Canadian research, the Nuvvuagittuq Greenstone Belt in Canada has been dated to as much as about 4.156 billion years old. This means that this bedrock formed during the Earth’s earliest geologic eon, the Hadean. Studying this Canadian rock thus offers us rare and valuable insight into what the newborn Earth might have been like.

Previous thoughts on the same topic:
Control of Douglas fir beetles by woodborer beetles
Diverging Findings in Antarctic Ice Sheet Research
Evolution Doesn’t Just Create New Species – It Can Also Reverse It