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प्रश्न
How are igneous rocks classified on the basis of their chemical composition?
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उत्तर
On the basis of chemical composition igneous rocks may be classified into two groups i.e. Acid igneous rocks and Basic igneous rocks. Acid rocks have silica content 65-85 percent e.g. granite which is made up of large crystals of quartz, feldspar and mica. Basic rocks contain high percentage oxides of denser material, silica content is between 40-60 percent with a density of 2.8 g/cm3 and 3.0 g/cm3. Acid rocks are lighter than Basic rocks.
संबंधित प्रश्न
Rocks and minerals play a very important role in our lives.
What problems would you face in their absence?
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Granite is an example of intrusive ________ rocks.
The photograph shows you a type of rock that is widely used in the construction industry.
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What is Geology?
Why are the igneous rocks also called the primary rocks?
Give two examples of metamorphic rocks.
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Calcarious and Carbonacious rocks.
What is metamorphism?
In what type of rocks do you find fossils and why?
Classify the following rock: Peat
Classify the following rock: Granite
Give one term for the following statement:
Sheet like body of igneous rock.
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Extrusive rocks generally have small crystals.
Give reasons for the following
Man’s habitat is the biosphere and not the lithosphere in the true sense.
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Statement (2) : Sedimentary rocks are formed by the sediments deposited at different points of time
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| A. | Basalt | 1. | Anthracite |
| B. | Limestone | 2. | Extrusive igneous |
| C. | Coal | 3. | Metamorphic rock |
| D. | Gneiss | 4. | Sedimentary rock |
