Pangaea: how a supercontinent formed and broke up
Pangaea was a supercontinent containing most of Earth's landmasses. It joined regions now separated by oceans. South America lay beside Africa, and North America beside Europe. Yet this was neither the first such assembly nor a permanent landmass that had existed since Earth formed.
Open Pangaea on the continental drift map, 250 million years ago to see the difference. Colours indicate the present-day continental affinity of the fragments. They let us recognise the material of later continents within the larger assembly, instead of seeing one undifferentiated island.
Assembled from lands with their own histories
Pangaea came together in stages during the late Palaeozoic. USGS places its main interval of existence at roughly 300 to 200 million years ago. These dates provide a useful outline, rather than two instantaneous events affecting the entire planet.
Its large southern component was the older Gondwana. On the other side lay, among other landmasses, Laurussia, previously assembled from Laurentia, Baltica and Avalonia. Successive collisions closed oceans and built mountain belts. Veevers (2004) traces Gondwana's continuing identity even while it formed part of Pangaea.
How do we know the ocean was not there?
The fit between Africa and South America is a clue, but it is not sufficient by itself. Modern shorelines change with erosion, sedimentation and sea level. Matching geological structures across the ocean and related fossils within corresponding rocks provide stronger evidence.
USGS describes these observations in its history of continental drift. Today, researchers combine them with rock ages, records of the ancient magnetic field and the age of the ocean floor. A convincing reconstruction must agree with several independent observations, rather than simply matching shapes in an atlas.
Breakup was not a single crack
Stretching of the lithosphere created rifts, broad zones where crust thinned and pulled apart. Where separation progressed far enough, new oceanic crust formed between the fragments. This process opened the Atlantic. Other parts of the supercontinent separated later, so there is no single date when all modern oceans opened.
Laurasia names the northern continental assembly in this history. It is not another name for the whole of Pangaea. Likewise, Gondwana did not first appear when Pangaea broke apart.
What does the animation show?
Our map moves continental crustal blocks from the reconstruction of Cao and colleagues (2024). Their edges are not exact shorelines, and their colours do not encode climate or mountain height. Pangaea appears as a labelled group of those blocks.
Try moving backwards to before assembly, then forwards towards the present. A supercontinent's name describes an arrangement, while its material continues travelling. Pangaea Ultima explores a similar idea of continents coming together again, but as a conditional future scenario.