Question: Why Are Continents So Much Older Than The Ocean Basins?

Why are the most ancient rocks found on the continents not on the ocean floor?

Why are the most ancient rocks on earth found only on the continents, whereas only relatively younger rocks are found on the ocean floor.

The continental crust is less dense so the oceanic crust subducts back to the mantle.

This process explains why the younger rocks are found on the ocean floor..

What do the side slits represent?

The side slits stand for old crust sinking back into the mantle of the Earth. The space under the paper stands for the stands for the mantle itself. 3.) How does the ocean floor as shown by the part of the strip close to the center slit differ from the ocean floor as shown by the part near the side slit?

Why are continents higher than the ocean floor?

Both oceanic crust and continental crust are less dense than the mantle, but oceanic crust is denser than continental crust. This is partly why the continents are at a higher elevation than the ocean floor. … As a result, the rock that forms from that melt is less dense than the original rock.

Which is the oldest continent on earth?

AustralianThe Australian continent, being part of the Indo-Australian Plate (more specifically, the Australian Plate), is the lowest, flattest, and oldest landmass on Earth and it has had a relatively stable geological history.

Where would you look in order to find the oldest rocks on Earth?

The Nuvvuagittuq Belt on the coast of the Hudson Bay in Northern Quebec. Scientists have found the oldest known rocks on Earth. They are 4.28 billion years old, making them 250 million years more ancient than any previously discovered rocks.

What are the most prominent features on the ocean floor?

Terms in this set (60)Continental shelf. … Continental slope. … Continental rise. … Deep ocean basins. … Abyssal plains. … Deep-ocean trenches. … Seamounts. … Oceanic ridges. The most prominent feature on the ocean floor and are composed of igneous rock that has been fractured and uplifted.More items…

Why continental and oceanic rocks are different ages?

Differences in Age Oceanic and continental plates differ radically in age because of tectonic processes. Divergent plate boundaries continually renew oceanic plates while the subduction zones of convergent boundaries continually recycle them. As a result, the oldest oceanic rocks are less than 200 million years old.

How do continents differ from ocean basins?

Continents? Ocean basins grow over time while continent shift closer making the opening of the Atlantic longer and the length of the pacific shorter.

Why do you think that the oldest ocean floor is only about 200 million years old?

The ocean floor is the ultimate recycling center. While the Earth’s continental crust can exist for billions of years, movement of tectonic plates causes subduction, which is when the ocean crust is shoved down into the molten mantle. So the ocean floor rarely lasts longer than 200 million years.