Overview - Timescale, Physical Landscapes

Phanerozoic eon

• Cretacious Period
  
  
  • Lower
    
    • Berriasian
      
    • Valanginian
      
    • Hauterivian
      
    • Barremian
      
    • Aptian
      
    • Albian
      
    
    
    
  
  
  • Upper
    
    • Cenomanian
      
    • Turonian
      
    • Coniacian
      
    • Santonian
      
    • Campanian
      
    • Maastrichtian
      
    
    
    
  
  
  
  

The Cretaceous period began with two separate continents, Laurasia in the north and Gondwana in the south. These two continents were almost completely separated by the equatorial Tethys Strait, and the continents of Laurasia and Gondwana had already begun to break apart. During the Jurassic, North America began to separate from Eurasia, South America separated from Africa, and from there India, Australia and Antarctica separated. By the end of the Cretaceous, most of the present-day continents were separated by the North and South Atlantic Oceans. At the end of the Cretaceous, India drifted into the Indian Ocean and Australia was still connected to Antarctica.

So the Cretaceous was a period of major changes in the position of Earth's land masses over a long period of time. During the Cretaceous, there were two supercontinents, Gondwana in the south and Laurasia in the north. South America, Africa, Antarctica, Australia, India, Madagascar and several smaller continents joined Gondwana in the south, while North America, Greenland and Eurasia formed Laurasia. Africa separated from South America, with Brazil and Nigeria being the last landlocked regions. As a result, the South Atlantic joined the expanding North Atlantic. In the Indian Ocean, Africa and Madagascar separated from India, Australia and Antarctica during the Late Jurassic and Early Cretaceous. After separation from Australia and Antarctica, India started moving northward and collided with Asia during the Cenozoic. In the Late Cretaceous, Madagascar separated from Africa and Greenland separated from North America. Australia was still attached to Antarctica. They barely came together at the junction of modern North and South America.