silicon
The mantle has less aluminum and less silicon than the crust does.
The mantle has less aluminum and silicon than the crust does.
The mantle is denser than the crust because it contains more iron and magnesium-rich minerals. These minerals have a higher density compared to the minerals found in the crust, such as silica and aluminum.
Crustal rock is normally less dense than mantle rock.
The crust lies on top of the mantle because it is composed of less dense materials than the mantle is. The crust is essentially floating on the mantle.
the crust(~2.7g/cm3) is less dense than the mantle(~3.3 g/cm3)
If continental crust were thinner than its average thickness of 40km, it would depress the mantle less than it does now. This is because less mass in the thinner crust would exert less pressure on the mantle, resulting in less depression.
the crust is lighter and less dense than the mantle...thus it floats on top.
Continental crust is less dense than oceanic crust, so it floats higher on the mantle. This means that the same thickness of continental crust will displace less mantle compared to oceanic crust. Additionally, continental crust is composed of lighter rocks like granites, while oceanic crust is made of denser rocks like basalt.
Ocean crust is typically denser than continental crust because it contains more basalt (rich in iron and magnesium), whereas continental crust is composed of less dense granite (richer in aluminum and silicon).
less dense than the material of the Earth's mantle
The outer core is composed of molten iron and nickel, which is much denser than the material that composes the mantle. So, in a sense, the mantle floats on top of the core just as the crust floats on top of the mantle.