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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?

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? Correct Answer 1 only

The correct answer is 1 only.

Key Points​

  •  Igneous Rocks:
    • Igneous rocks are formed by the cooling and solidification of molten rock (magma) from beneath the earth crust.
    • They are normally crystalline in structure. Hence, statement 1 is correct.
    • They do not occur in strata nor do they contain fossils. Hence, statement 2 is NOT correct.
    • Igneous rocks may be sub-divided on the basis of mineral composition.
      • When they contain a high proportion of silica they are said to be acid. Hence, statement 3 is NOT correct.
      • Basic rocks contain a greater proportion of basic oxides, e.g. of iron, aluminium or magnesium, and are thus denser and darker in colour.
    • In terms of origin, there are two main classes of igneous rocks.
      • Plutonic rocks
      • Volcanic rocks.

Related Questions

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 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?
Consider the following statements and choose the correct answer:
1. It is in the sedimentary rocks that fossils are found
2. Sedimentary rocks arise as a result of gradual deposition of silt or silica at the bottom of lakes or seas
3. Igneous rocks are those in which the original structure has been changed by heat or pressure
4. Entire plants or animals or more commonly their parts are found fossilised
Which of the following are true with regard to igneous rocks? I. They are formed inside the earth, under great pressure II. They do not occur in layer III. They are mostly crystalline in nature IV. They contain fossils
Which of the following are true with regard to igneous rocks?
I. They are formed inside the earth, under great pressure
II. They do not occur in layer
III. They are mostly crystalline in nature
IV. They contain fossils
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 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 following statements about the sedimentary rocks: 1. Sedimentary rocks are formed by lithification. 2. Coal deposits occur in river basins of the Damodar, Mahanadi, the Godavari in the Gondwana sedimentary deposits. 3. They hold the most informative geological records due to the marks left behind by various geophysical (weather patterns, wind, and water flow) and biological activities (fossils). 4. Granite, gabbro, basalt, are some of the examples of sedimentary rocks. Which of these statements are correct?
Which of the following rocks have a chance to contain fossils? (A) Sedimentary rocks (B) Metamorphic rocks (C) Igneous rocks
Consider the statements A, B, C on metamorphic rocks and choose the correct answer: A. When igneous and sedimentary rocks are subjected to heat and pressure they change to metamorphic rocks. B. Metamorphic rocks melt to form molten magma when subjected to great heat and pressure. C. Marble is a metamorphic rock.