Which of the following statements is are correct The density of oceanic crust is less than the densi...........

Geography and Environment (RAS) World Physical Aspects

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Which of the following statements is/are correct?

The density of oceanic crust is less than the density of continental crust.
Asthenosphere is the main source of magma.
Oceanic crust is made up of Basalt while continental crust is made up of Granite.

Select the correct answer using the code given below:

1 and 2 only

2 and 3 only

1 and 3 only

1, 2 and 3

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Explanation:

S1 is incorrect because continental crust is less dense than oceanic crust.
Oceanic crust is generally composed of dark-colored rocks called basalt and gabbro. It is thinner and denser than continental crust, which is made of light-colored rocks called andesite and granite. The low density of continental crust causes it to “float” high atop the viscous mantle, forming dry land.

The continental crust is composed of granitic rocks, which have even more silicon and aluminum than the basaltic oceanic crust and are less dense than basalt.

Asthenosphere, zone of Earth’s mantle lying beneath the lithosphere and believed to be much hotter and more fluid than the lithosphere. Convection currents generated within the asthenosphere push magma upward through volcanic vents and spreading centres to create new crust.