Driven by heat from the core, convection currents churn the solid silicates of the mantle, pushing and pulling the thin plates of crust, bringing continents together and tearing them apart in cycles which can last for hundreds of millions of years. This shifting can also bring several continents into close enough proximity to form a single landmass above sea level. These clusters are known as supercontinents; the most famous of which is Pangea.

Pangea formed roughly 335,000,000 years ago and existed as a single landmass for approximately 160,000,000 years. The breakup came after a series of powerful rifting events in which strong pulses of magma forced continental plates apart at the seams, creating new crust and opening up the basin in which the Atlantic Ocean eventually took shape.

Known as the Central Atlantic Magmatic Province (CAMP), the extant remnants of these flood basalts can be found in former rifts located in modern-day Morocco, Southwestern Europe, the Amazon River Basin, and Eastern North America.

This specimen is a polished diabase fragment from the Central Atlantic Magmatic Province deposits of Eastern North America. It comes affixed to its informational card which also serves as certificate of authenticity.

The source rock was donated by the Luck Stone quarry adjacent to the Manassas U.S. Civil War battlefield in Northern Virginia. The quarry is a magnificent location where it is possible to clearly see one of the rift valleys which tore through the ancient supercontinent and might once have become the Atlantic Ocean.

As with other major geological events, CAMP was not simply a gentle shifting of landmass. The upheaval correlates with another massive extinction event in the fossil record: the Triassic–Jurassic extinction event. Nearly half of all species on Earth became extinct during this event, and it is considered the final clearing point which allowed the dinosaurs to cement their dominance for the next 135,000,000 years.

The hard surface of our planet, the lithosphere, is broken into plates which wander over time. Just over one hundred years ago, in 1912, Alfred Wegener proposed that all the continents once formed a single supercontinent he named Pangea. The basic concepts underlying his continental drift theory were eventually accepted and incorporated into plate tectonics in the 1960s. 

However, Pangea is only the most recent supercontinent. Before Pangea there were two supercontinents: Laurasia in the north (North America, Greenland, Europe, and northern Asia) and Gondwana in the south (South America, Africa, Antarctica, Australia and India).

Pangaea was not a singular event but part of a continuing planetary rhythm known as the supercontinent cycle. Over billions of years, the continents have joined together and drifted apart many times. The same mantle currents that once tore Pangaea apart are still at work beneath our feet, slowly carrying the continents toward their next union. In roughly 200 to 250 million years, those movements will bring the landmasses together again to form a new world.

Scientists have proposed different visions of what that future supercontinent might look like. One model, called Pangaea Proxima, suggests that the Atlantic Ocean will continue to widen before reversing course. The Americas would eventually move back toward Africa and Eurasia, gathering the continents around the basin that once held the Indian Ocean. Another possibility, known as Amasia, imagines the closure of the Pacific Ocean as the Americas drift westward to meet Asia, with Antarctica moving north to join the new landmass near the top of the world.

Whatever form it takes, the next supercontinent will transform the planet as completely as Pangaea once did. A vast single landmass would limit the moderating effect of the oceans, creating deep interior deserts and sharp seasonal extremes. As the ocean ridges slow and the seafloor cools, the water of the world will retreat, exposing wide continental shelves and lowering global sea levels. Life will change in response, just as it always has. Harsh conditions will push some species to extinction while others adapt and thrive, beginning a new cycle of evolution.

To imagine the next supercontinent is to look forward into the same forces that shaped our distant past. The continents continue to wander, and in their slow journey they carry the memory of every world that came before.