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Which of the following topics are necessary to be covered BEFORE introducing the topic 'extrusive igneous rocks'? i) Lava ii) Interior of the Earth iii) Sediments iv) Basalt

Which of the following topics are necessary to be covered BEFORE introducing the topic 'extrusive igneous rocks'? i) Lava ii) Interior of the Earth iii) Sediments iv) Basalt Correct Answer i, ii

Before introducing the topic 'extrusive igneous rocks' the following topics are necessary to be covered:

i) Lava

ii) Interior of the Earth

Important Points

  • Interior of the Earth:
    • The earth is made up of several concentric layers with one inside another.
    • The interior of the earth can be divided into 3 different layers – crust, mantle, and core.
    • The uppermost layer over the earth’s surface is called the crust. The earth’s crust is made up of various types of rocks. 
    • Just beneath the crust is the mantle which extends up to a depth of 2900 km. below the crust. 
    • The innermost layer is the core with a radius of about 3500 km. It is mainly made up of nickel and iron.
  • Lava:

    • Lava is actually fiery red molten magma coming out from the interior of the earth on its surface. 

  • Once the students are clear about the interior of the Earth and meaning of lava, then it will be easy for them to understand about the topic 'extrusive igneous rocks'.

  • There are three major types of rocks: igneous rocks, sedimentary rocks and metamorphic rocks. 
  • When the molten magma cools, it becomes solid. Rocks thus formed are called igneous rocks. They are also called primary rocks.
  • There are two types of igneous rocks: intrusive rocks and extrusive rocks.
  • Extrusive  igneous rocks:
    • ​When the molten lava comes on the earth’s surface, it rapidly cools down and becomes solid.
    • Rocks formed in such a way on the crust are called extrusive igneous rocks.
    • They have a very fine grained structure.

    • For example, basalt. The Deccan plateau is made up of basalt rocks.

Hence, we can conclude that the following topics are necessary to be covered BEFORE introducing the topic 'extrusive igneous rocks'

i) Lava

ii) Interior of the Earth

Related Questions

Which of the following statements is/are correct regarding Igneous rocks? 1. Intrusive igneous rocks are formed by the cooling of lava on the earth’s surface. 2. Extrusive igneous rocks are formed when magma solidifies below the earth’s surface.
Consider the statement A, B, C on igneous rocks and choose the correct answer. Statement (A): Sedimentary rocks, when subjected to heat and pressure turn into igneous rocks. Statement (B): These rocks are found both on the earth's crust and deep inside the earth's crust. Statement (C): Granite and Basalt are examples of igneous rocks. 
Consider the following: Type of Rocks Process of formation 1.Igneous Rocks Formed out of existing rocks undergoing recrystallization 2.Sedimentary Rocks The result of the deposition of fragments of rocks by exogenous processes. 3.Metamorphic Rocks Solidified from magma and lava   Which of the above pair/s is/are correctly matched?
Which of the statements is/are correct?
1. Igneous rocks are classified into Extrusive and Intrusive rocks.
2. Sedimentary rocks are also called as Primary rocks
3. Marble is an example of Metamorphic rocks
4. Coal is a sedimentary rock
According to geological classification, rocks are divided into three different categories i.e. Igneous rocks, Sedimentary rocks and Metamorphic rocks. In which category Granite, Basalt and Dolerite etc types of rocks fall?
Consider the following statements:
1. The acid lava usually melts at a relatively higher temperature as compared to basic (basaltic) lava.
2. The acid lava solidifies into glass-like sheets and the basaltic lava solidifies into rough surfaces.
Which of the statements given above is/are correct?
In the question below are given four statements followed by two conclusions numbered I and II. You have to take the given statements to be true even if they seem to be at variance with commonly known facts. Read all the conclusions and then decide which of the given conclusions logically follows from the given statements disregarding commonly known facts. Statements: Some Adidas are Lava. Some Lava are Iron. Some Iron are Samsung. Some Samsung are Rod. Conclusions: I. Some Lava are Adidas. II. Some Samsung are Lava.
Consider the following regarding the Igneous rocks:  I. There are no layers in these rocks.  II. Fossils are not found in these rocks.  III. The formation of these rocks takes place only beneath the surface of the earth.  Which among the above is/are correct?
Which of the following topics are necessary to be covered BEFORE introducing the topic of earthquakes? i) Magma ii) Exogenic forces iii) Lithosphere iv) Epicentre
Consider the following statements about the igneous rocks; 1. Igneous rocks are normally crystalline in structure. 2. They occur in strata and contains fossils. 3. These rocks have no silica. Which of the statements given above is\are correct?