It’s been estimated that in all of Earth’s history, there have been 7 supercontinents, with the most recent one being Pangaea.
The next supercontinent (Pangaea Ultima) is expected to form in around 250 million years.
Why is this the case? What phenomenon causes these giant landmasses to coalesce, break apart, then coalesce again?
In: 1126
Have a read of some of Graeme Begg’s work.
Possible that they are almost self organised, and the breakup of the previous supercontinent is the driver for the breakup of the new supercontinent. Basically just shifting backwards and forwards across the surface.
Keeping it really simple, the surface of the earth moves by sinking on one edge and splitting apart at another. The driver for this is in a basic (for supercontinents) is suggested to be very hot upwelling of mantle forcing the surface apart. Once the process is rolling, the sinking edge continues the process by dragging the rest of the plate with it.
The sinking edge eventually breaks and sinks into the mantle, stopping the process. The broken edge keeps sinking, becoming super hot and possibly reaches core/mantle boundary.
The superheated broken edge shoots back up to the surface as an “alpha plume”, and the whole process starts again. This is thought to be on a roughly 800Ma cycle, aligning with supercontinent cycles.
This is grossly oversimplified, but if interested search G.Begg and Griffin for supercontinent cycles on Google scholar.
This process is important for mineral exploration, as the VAST majority of magmatic Nickel deposits form on the 800Ma cycle, and are strongly correlated with break apart phases of supercontinents
Latest Answers