• Break-up of the supercontinent Gondwana 130 Million years ago could have lead to a completely different world
  • Would have dramatically altered shape of the African and South American continent
possible ancient africa
© Christian Heine and Sascha BruneHow South America could have ruled the world: New image shows how the Earth MIGHT have looked if Africa had been split in two. The move would have left a huge ocean south of today's Sahara desert, creating a South Atlantic and a Saharan Atlantic Ocean.
Researchers have revealed a fascinating glimpse of how the world could have looked - if a shift in the Earth's tectonic plates had taken a slightly different turn.

Australian researchers say the break-up of the supercontinent Gondwana about 130 Million years ago could have lead to a completely different shape of the African and South American continent.

They say the move would have left a huge ocean south of today's Sahara desert, creating a South Atlantic and a Saharan Atlantic Ocean.

Geoscientists from the University of Sydney and the GFZ German Research Centre for Geosciences used sophisticated plate tectonic and three-dimensional numerical modelling to recreate the shift - but with a different twist.

The researchers say the shift that left Africa it its present location was almost very different.

'Extension along the South Atlantic and West African rift systems was about to split the African-South American part of Gondwana North-South into nearly equal halves, generating a South Atlantic and a Saharan Atlantic Ocean', geoscientist Sascha Brune said.
africa today
© alamy
How the Earth looks today: Researchers say a minor change in the twist of a tectonic plate could have led to a very different Africa
'In a dramatic plate tectonic twist, however, a competing rift along the present-day Equatorial Atlantic margins, won over the West African rift, causing it to become extinct, avoiding the break-up of the African continent and the formation of a Saharan Atlantic ocean.'

The team say their study highlights the importance of rift orientation relative to extension direction as key factor deciding whether an ocean basin opens or an aborted rift basin forms in the continental interior.

For hundreds of millions of years, the southern continents of South America, Africa, Antarctica, Australia, and India were united in the supercontinent Gondwana.

While the causes for Gondwana's fragmentation are still debated, it is clear that the supercontinent first split along along the East African coast in a western and eastern part before separation of South America from Africa took place.

Today's continental margins along the South Atlantic ocean and the subsurface graben structure of the West African Rift system in the African continent, extending from Nigeria northwards to Libya, provide key insights on the processes that shaped present-day Africa and South America.

The South Atlantic part of this giant rift system evolved into an ocean basin, whereas its northern part along the West African Rift became stuck.

The team say their complex numerical models gave a simple explanation: the larger the angle between rift trend and extensional direction, the more force is required to maintain a rift system.

The West African rift featured a nearly orthogonal orientation with respect to westward extension which required distinctly more force than its ultimately successful Equatorial Atlantic opponent.