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प्रश्न
How are igneous rocks formed?
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उत्तर
Igneous rocks are formed by the cooling and solidification of molten rock called magma, which lies beneath the earth’s crust. These rocks are crystalline and compact. They do not occur in layers or strata, nor do they contain fossils. The cooling and solidification may take place at some depth within the earth or at the surface. The molten magma that reaches the surface of the earth is called lava. Thus, there are two types of igneous rocks classified on the basis of their place of origin – intrusive rocks, which form at some depth in the earth’s crust and extrusive rocks which form at or near the surface of the earth.
संबंधित प्रश्न
Rocks and minerals play a very important role in our lives.
What problems would you face in their absence?
Write True or False. Rewrite the false statement correctly :
Minerals are organic substances.
Why are the igneous rocks also called the primary rocks?
Give two examples of metamorphic rocks.
Explain this term associated with rocks: Lithification of Rocks.
Distinguish between Regional and Contact metamorphism.
Classify the following rock: Clay
Classify the following rock: Rock salt
Classify the following rock: Limestone
Classify the following rock: Gneiss
Classify the following rock: Schist
Give one word for the following.
The lower part of ocean floor, comprising mainly of silica.
Give one word for the following.
Rocks formed by the cooling and solidification of molten rock from beneath the earth crust.
Give one example of an area of: Sedimentary rocks in India
Why are Sedimentary rocks called the Secondary rocks?
State the properties of metamorphic rocks.
Give one term for the following statement:
Sheet like body of igneous rock.
How is Plutonic rock formed?
Give an example of a Plutonic rock.
Which of the following monuments are built-in igneous rock?
- The Taj Mahal
- Fort Raigad
- The Red Fort
- Ellora Sculpture
______ is the kind of metamorphic rock using which Taj Mahal was built.
How are igneous rocks formed?
An aggregate of minerals on the Earth’s Crust is called ______.
Match the following.
| A. | Basalt | 1. | Anthracite |
| B. | Limestone | 2. | Extrusive igneous |
| C. | Coal | 3. | Metamorphic rock |
| D. | Gneiss | 4. | Sedimentary rock |
Match the following.
| Group A | Group B | ||
| A. | Basalt | 1. | Anthracite |
| B. | Limestone | 2. | Extrusive igneous |
| C. | Coal | 3. | Metamorphic rock |
| D. | Gneiss | 4. | Sedimentary rock |
Match the following:
| A. | Basalt | 1. | Anthracite |
| B. | Limestone | 2. | Extrusive igneous |
| C. | Coal | 3. | Metamorphic rock |
| D. | Gneiss | 4. | Sedimentary rock |
