The Earth’s continents are constantly moving across the planet’s surface, a process known as continental drift. Hundreds of millions of years ago, all the major landmasses were joined together in a single, immense supercontinent called Pangea. To understand the current position of the world’s largest island, Greenland, it is necessary to look back at where it was situated within this unified ancient landmass.
Understanding Pangea’s Structure
Pangea was fully assembled by the Early Permian Epoch, roughly 335 million years ago, and began to break apart around 175 million years ago. This vast continent was organized into two main parts. The northern half, which contained most of today’s northern continents, is known to geologists as Laurasia.
The southern half of the supercontinent was called Gondwana, which was comprised of the landmasses that would eventually form South America, Africa, Antarctica, Australia, and India. The Tethys Ocean bordered Pangea, which was surrounded by a single global ocean called Panthalassa. Greenland was firmly rooted in the northern section.
Greenland’s Position within Laurasia
Modern Greenland was a landlocked part of Laurasia, situated deep within the northern supercontinent. Structurally, it was part of the North American Craton (Laurentia), the ancient, stable core of the North American continent, positioned far from the ocean waters that surround it today.
Greenland was tightly nestled in a narrow space between two massive continental bodies. To its west, it was pressed against what is now the eastern coast of Baffin Island and the rest of the Canadian landmass. To its east, it abutted the western edges of what would become Northern Europe, specifically connecting to Norway and Scotland. The landmass was situated near the paleo-North Pole. Its placement meant that it acted as a geological seam, bridging the North American and Eurasian components of Laurasia, making it a central participant in the eventual separation of the continents.
Greenland’s Role in the Breakup
Greenland’s current isolated island status is a direct result of the rifting that began to fracture Pangea, a process that started in the Jurassic period. The initial splitting that created the central Atlantic Ocean soon propagated northward, leading to the formation of the North Atlantic. This process saw Greenland initially remain attached to the North American plate.
The first major separation involving Greenland occurred as the Labrador Sea began to open between Greenland and Canada, starting around 62 million years ago. This rifting continued into Baffin Bay around 57 million years ago, effectively separating Greenland from the main body of North America. However, the seafloor spreading in this western rift eventually ceased between 30 and 35 million years ago, leading Greenland to largely move as a single unit with the North American plate once again.
A later and more complete separation occurred along Greenland’s eastern edge, beginning around 54 million years ago. This final rifting, which separated Greenland from the Eurasian plate, opened the northeastern part of the Atlantic Ocean. The movement was complex, involving multiple phases of rifting and the eventual establishment of the Mid-Atlantic Ridge, which now defines the tectonic boundary between the continents.
Geological Legacy
The Precambrian basement rock of Greenland, which includes some of the oldest crustal material on Earth, is recognized as an extension of the Laurentian Shield, the ancient bedrock of North America. This connection shows that the landmass was structurally continuous with the North American continent for billions of years.
Further confirmation comes from the matching mountain belts that formed during the assembly of Pangea. The Caledonian Mountains, created by an ancient continental collision, have matching rock formations that span across Greenland, Scandinavia, and the British Isles. Similarly, the geology of the Appalachian Mountains in North America aligns with these same structures, proving that all these landmasses were once fused together.