These are different parts of a question. I just need their brief answers in two

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These are different parts of a question. I just need their brief answers in two or three lines in proper way. Thanks

Question a. The classification (naming) of igneous rocks is based largely on two criteria Name these criteria. b. How are specimens of granite and rhyolite different? In what way are they similar? List the minerals present in granite. (specify the feldspar types) List the minerals present in basalt. Why is granite light in color while basalt is dark? Why is granite coarse grained while basalt is fine grained? Explain how (the manner in which; the mechanism) SiO2 content influences c. d. e. f. g. the viscosity of a magma. h. Why are andesitic volcanic eruptions more violent than basaltic eruptions?

Explanation / Answer

A. Classification of igneous rock is generally classified on the basis of texture and chemical composition of the rocks.

B. Rhyolite and granite are similar in their composition of minerals but Rhyolite is volcanic rock where as granite is plutonic rock.

C. Major minerals present in granite are quartz and feldspars. Both plagioclase and alkali feldspars (orthoclase) are present.

D. Basalt is mostly composed of calcic plagioclase feldspars and pyroxenes among which feldspars dominate. Olivine also present in significant amount.

E. Granite contains felsic minerals like quartz, feldspars which are lighter in color but Basalt contains mafic minerals like pyroxenes and Olivine which are darker in color.

F. Granite is coarse grained as it plutonic rock and texture varies due to different type of cooling than the sudden cooling of Basalt as it is volcanic rock.

G. As SiO2 composition increases the degree of polymerization viscosity of Magma is increased.

H. Andesitic mama's generally have lower densities but higher viscosities than basaltic magma causing violent andesitic eruptions.

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