Question

3. Answer the following
PA) What are the two parts of the crust?
What is the basis of classification?
please answer me guys I love you really​

Answer 1

Earth's crust is divided into two types: oceanic crust and continental crust. The transition zone between these two types of crust is sometimes called the Conrad discontinuity. Silicates (mostly compounds made of silicon and oxygen) are the most abundant rocks and minerals in both oceanic and continental crust. I hope its help you. Thank you

Answer 2

$\sf{ \green{What \: are \: the \: two \: parts \: of \: the \: crust?}}$

$\sf{ \green{What \: is \: the \: basis \: of \: classification?}}$

$\large{ \rm{ \orange{Answer:}}}$

On the basis of composition, the crust is generally divided into two parts:

① Sial

② Sima

Sial:

❥ The upper part of the crust is the 'sail' zone.

❥ Silicon and aluminium are the two most important constituent elements of this outer part of the crust.

❥ Upper part of crust is called 'sial' layer because of the presence of these two minerals i.e., silicon and aluminium.

❥ It is lighter than the rocks forming the sima zone.

Sima:

❥ The lower part of the crust is the 'sima' zone.

❥ It is made up of silicon and magnesium type of material.

❥ Lower part of the crust is called 'sima' because of presence of these two minerals i.e., silicon and magnesium.

❥ They are heavier than the rocks forming the sial zone.

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$\sf{ \green{Two \: types \: of \: crust \: can \: be \: indentified \: as:}}$

① Oceanic crust

② Continental crust

Oceanic crust:

✪ Itis thin and measures between 5 to 10 kilometres thick.

✪ It is composed of the salt.

✪ It has density of about 3.0 grams per cubic centimetre.

Continental crust:

✪ The continental crust is 22 to 70 kilometres thick.

✪ It is composed mainly of lighter granite.

✪ The density of continental crust is about 2.7 grams per cubic centimetre.

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♖ $\blue{ \bold{Crust:}}$

◍ The topmost part of the lithosphere consists of crust.

◍ Solid rocks forms the crust.

◍ Silicon, aluminium and magnesium are the major minerals that make up the crust.

◍ The thickness of crust varies from 6 to 48 kilometre.

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