As with anything new related to geology, looking forward requires scrutinizing the almost unimaginable past. The dominant hypothesis is that Earth's first supercontinent, Rodinia, formed 1.1 billion years ago. Plates shifted, more stuff happened, a land called Gondwana united, more stuff happened again, and then a mere 250 million years ago, Pangea came together.
Over time, rifting tore this giant supercontinent apart and the puzzle pieces scattered across the globe looking more like the continents we know. Keep in mind this is all dramatically happening at speeds about as fast as your fingernails grow.
Since the 1990s, several well-known models for a future supercontinent have been introduced. Harvard University geologist Paul Hoffman was the first to dub one version "Amasia." Until now there had been two dominant models of how and where Amasia will form. Both predicted the landmasses to converge along the equator, but differed on whether it would happen in the same place as Pangea was before or on the other side of the world.
Yale University geology and geophysics professor David Evans, along with graduate students Taylor Kilian and Ross N. Mitchell, studied the magnetism in ancient rocks to figure out where they were positioned and measured how the material under continents are moving the masses.
"The Americas will remain in the Pacific ‘ring of fire’ girdle of post-Pangaean subduction, closing the Arctic Ocean and Caribbean Sea," the Yale geophysicists wrote in a Nature journal article published today. In other words, they think Amasia will form over the Arctic, 90 degrees away from the original Pangea.
To geologists, the Yale group's idea makes sense. After all, previous supercontinents appear to have formed successively at 90 degrees to each other.
Read more at Discovery News
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