Question

task 3
there are two types of earths crust:
i. oceanic crust
ii. continental crust
using this link, explain the main differences between them both.
complete the table beneath to show the differences between the two plate types.

feature	oceanic crust	continental crust
how thick in km?
age in years
typical rock type
brief explanation of formation

Explanation:

Step1: Surface coverage

Oceanic crust covers a larger portion of the Earth's surface due to the vastness of the oceans. Continental crust covers the remaining land - based areas.

Step2: Thickness

Oceanic crust is much thinner as it is formed by rapid cooling of magma at mid - ocean ridges. Continental crust is thicker due to processes like mountain building and the accumulation of sediments over time.

Step3: Age

Oceanic crust is relatively young because it is constantly being recycled at subduction zones. Continental crust is older as it is more stable and less likely to be subducted.

Step4: Rock type

Oceanic crust is mainly basalt which is a dense, fine - grained igneous rock formed from rapid cooling of magma. Continental crust is mainly granite which is less dense and coarser - grained.

Step5: Formation explanation

Oceanic crust forms at mid - ocean ridges where magma wells up from the mantle and cools quickly. Continental crust forms through a combination of volcanic activity adding material, sedimentation, and tectonic collisions that cause the crust to thicken and grow.

Answer:

Feature	Oceanic Crust	Continental Crust
How thick in km?	5 - 10 km	30 - 70 km
Age in years	Generally younger, up to about 200 million years old	Can be very old, up to 4 billion years old
Typical rock type	Basalt	Granite
Brief explanation of formation	Forms at mid - ocean ridges as magma rises and cools. New crust is constantly being created.	Forms through processes like volcanic activity, sedimentation, and tectonic collisions over long periods of time.