GK
WORLD GEOGRAPHY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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the chemical composition of the magma
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temperature of solidification
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the rate of cooling, which influences the crystallisation process
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All of the above
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Detailed explanation-1: -Extrusive, or volcanic, igneous rock is produced when magma exits and cools above (or very near) the Earth’s surface. These are the rocks that form at erupting volcanoes and oozing fissures.
Detailed explanation-2: -Igneous minerals crystallize from a magma to form igneous rocks. Magmas have variable compositions giving rise to many different kinds of rocks containing different minerals. Cooling rate affects crystal size and rock texture. Minerals crystallize in an orderly and predicable way during magma cooling.
Detailed explanation-3: -Igneous rocks form when molten rock (magma or lava) cools and solidifies.
Detailed explanation-4: -Virtually all of the igneous rocks that we see on Earth are derived from magmas that formed from partial melting of existing rock, either in the upper mantle or the crust.