Which one of the following is a minor tectonic plate?
- A.Nazca plate
- B.Indo-Australian plate
- C.Antarctic plate
- D.African plate
Correct answer
Explanation
The correct answer is A, the Nazca plate. It lies between South America and the Pacific plate and is one of the well known minor plates, along with the Cocos, Arabian, Philippine, Caribbean, Juan de Fuca, Scotia, Caroline and Fuji plates. The seven major plates are the Pacific, North American, South American, Eurasian, African, Indo-Australian and Antarctic plates. Option B, the Indo-Australian plate, is a major plate and carries India, Australia and New Zealand, which is why it is sometimes counted as two. Option C, the Antarctic plate, is a major plate and is almost entirely surrounded by divergent boundaries. Option D, the African plate, is a major plate that is being split along the East African Rift Valley. The subduction of the Nazca plate under South America has raised the Andes.
Read the full article: Continental Drift and Plate Tectonics: Exam Notes
Practice Questions
View allThe theory of continental drift was propounded by:
- A.Alfred Wegener
- B.Harry Hess
- C.Arthur Holmes
- D.Charles Lyell
Show answer
Wegener, a German meteorologist and climatologist, put forward the continental drift theory in 1912 and developed it in his book The Origin of Continents and Oceans; he argued that all the continents once formed a single landmass, Pangaea, which broke up about two hundred million years ago.
Read the full explanation →In Wegener's theory, the single great ocean that surrounded the supercontinent Pangaea was called:
- A.Tethys
- B.Panthalassa
- C.Laurasia
- D.Gondwana
Show answer
Wegener held that about two hundred and fifty million years ago all the land of the earth lay together as one mass, Pangaea, and that one enormous ocean, Panthalassa, surrounded it.
Read the full explanation →Which pair of forces did Wegener suggest as the cause of continental drift?
- A.Ridge push and slab pull
- B.Pole-fleeing force and tidal force
- C.Isostasy and gravity
- D.Convection currents and radioactivity
Show answer
Wegener attributed the horizontal movement of the continents to the pole-fleeing force, which arises from the rotation of the earth and the bulge of the equator, and to the tidal force, which arises from the attraction of the moon and the sun.
Read the full explanation →The Tethys Sea separated which two landmasses after the break-up of Pangaea?
- A.Laurasia and Gondwanaland
- B.Africa and South America
- C.India and Australia
- D.Antarctica and Australia
Show answer
When Pangaea began to break about two hundred million years ago, it parted into a northern mass called Laurasia or Angaraland and a southern mass called Gondwanaland, and the long narrow Tethys Sea lay between the two.
Read the full explanation →The concept of sea floor spreading was given by:
- A.Alfred Wegener
- B.Harry Hess
- C.Alfred Lothar Nazca
- D.Edward Suess
Show answer
After the detailed mapping of the ocean floor during and after the Second World War revealed mid-oceanic ridges, deep trenches and a surprisingly thin cover of sediment, Hess proposed in 1961 that molten material rises along the ridge, forms new ocean floor and pushes the older floor away on both…
Read the full explanation →