Continental Drift and Seafloor Spreading

Front

What is Continental Drift?

Back

The theory that continents have moved over geological time and were once joined together.

Front

Who proposed the hypothesis of Continental Drift?

Back

Alfred Wegener.

Front

What evidence did Wegener use to support his hypothesis?

Back

Fossil records, geological similarities, and the fit of continental coastlines.

Front

What is Seafloor Spreading?

Back

The process by which new oceanic crust is formed at mid-ocean ridges and older crust moves away.

Front

What role do magma and convection play in seafloor spreading?

Back

Magma rises from the mantle, creating new crust, while convection currents in the mantle drive the movement of tectonic plates.

Front

Where is the youngest seafloor found in the Atlantic Ocean?

Back

Along the Mid-Ocean Ridge.

Front

What geological features are commonly associated with seafloor spreading?

Back

Mid-ocean ridges, rift valleys, and volcanic islands.

Front

What was one reason early observers believed continents were once joined?

Back

The similarity of coastlines, such as the fit between South America and Africa.

Front

What technology did Wegener lack to support his hypothesis?

Back

He did not have the technology to measure the movement of continents.

Front

What is the significance of the Mid-Ocean Ridge?

Back

It is the longest mountain range in the world and the site of seafloor spreading.