Lesson 5 - Geological History of the Oceans Flashcards
What did the Earth’s geography resemble in the Proterozoic era?
600 - 700 Ma
A smattering of small continents arranged roughly in a ring close to the equator
By what year had over 90% of the Earth’s continental crust formed?
540 Ma
Cambrian Period
What are the names of the continents that were beginning to bunch together during the Cambrian period?
- Laurentia
- Siberia
- India
- Baltica
What supercontinent formed in the south during the early Devonian?
400 Ma
Gondwana
What smaller continent formed in the north during the early Devonian?
400 Ma
Laurentia
What was the name of the supercontinent that included Laurentia and Baltica?
Laurentia-Baltica or the Old Red Sandstone continent
By what year had virtually all continental crust joined to form the supercontinent Pangea?
248 Ma
End of the Permian
What was the name of the superocean that covered the Earth’s surface when all continental crust formed Pangea?
Panthalassa
During which period did Pangea begin to break up?
Jurassic Period
Around 200 Ma
What ocean began to form as Pangea split during the Jurassic?
Tethys Ocean
What significant geological event occurred by the early Cretaceous?
100 Ma
Pangea split from north to south
Which two continents split apart to form the South Atlantic Ocean?
- South America
- Africa
What geological feature was formed as a result of the subduction zone along the eastern margin of Panthalassa?
The volcanic belt from the Andes to Alaska
True or False: The continents we see today will remain unchanged for the next 200 million years.
False
What marked effects have the configuration of continents and oceans had?
Effects on climate and changes in sea level throughout geological history
What is likely to happen to the Atlantic Ocean over the next 50-100 million years?
It will probably continue to widen until a major subduction zone develops
What will happen to Africa’s position in relation to Europe?
It will continue its northward journey, crashing into Europe and closing the Mediterranean
What geological change is expected in the Red Sea region?
It will continue to open, pushing Africa and Arabia further apart
What is expected to happen in the Indonesian region in about 30 million years?
It will become a collision zone
What could happen to the Pacific Ocean if subduction rates outpace sea floor spreading?
It will eventually close
What might happen in around 200 million years regarding continental configuration?
There may be a new supercontinent and a new superocean
