Origins of Plate Tectonic Theory | Earth Science | Quiz

The contraction theory implied that Earth's features formed through the process of

continental drift.

magma upwelling.

cooling and contracting.

seafloor spreading.
What data did Wegener use to prove that the continents had once been joined together?

paleoclimate data

magnetic stripes

seafloor topography

magma
Although Wegener proposed his continental drift theory in 1915, it was not widely accepted until the 1960s. Why not?

Continental drift still did not explain the presence of marine fossils in the Himalayas.

Wegener's book was not read outside of Germany.

Wegener had not proposed a driving force for the movement of the continents.

Wegener had looked only at South America and Africa.
Who proposed the theory of seafloor spreading based on maps of the ocean floor?

Vine and Matthews

Alfred Wegener

a British geologist

Harry Hess
Why was the mapping of the ocean floor such an important step in the development of plate tectonic theory?

The features mapped on the ocean floor disproved continental drift.

Most plate boundaries are under the ocean.

The ocean floor had tracks from the continents

Nobody had known how deep the oceans were.
Earth's magnetic field is constant.

true

false
Which feature on the ocean floor caused Hess to suggest the presence of subduction zones?

flat plains

magnetic stripes

mid-ocean ridges

deep trenches
When did the Pangaean supercontinent begin to break up?

billions of years ago

200 million years ago

1915

in the 1960s
Vine and Matthews are considered to have discovered the final proof for seafloor spreading. What were they able to show based on magnetic bands?

Mid-ocean ridges and subduction zones are plate boundaries.

Seafloor rocks contain magnetite.

Earth's magnetic field had reversed in the past.

New crust is being generated at mid-ocean ridges.
Plate tectonic theory fundamentally altered how geologists view the earth. The biggest difference in the new theory was that Earth

is contracting.

is dynamic, constantly changing.

has numerous features on the ocean floor.

has a magnetic field that fluctuates.