The quartzite is a _______ type of rock.

Question

Question

This question was previously asked in

NTPC CBT-I (Held On: 7 Jan 2021 Shift 2)

Answer 1

The correct answer is Metamorphic.

Key Points

Metamorphic Rocks
- These rocks form under the action of volume, pressure, and temperature (PVT) changes.
- Metamorphism happens when rocks are forced down to lower levels by tectonic processes or when molten magma rising through the crust comes in contact with the crustal rocks or the underlying rocks are exposed to great amounts of pressure by overlying rocks.
- The materials of rocks chemically modify and recrystallize due to thermal metamorphism.
- There are two types of thermal metamorphism: Contact metamorphism and Regional metamorphism.
- Contact metamorphism: The rocks come in contact with hot intruding magma and lava and the rock materials recrystallize under high temperatures.
- Regional metamorphism: The rocks experience recrystallization due to deformation caused by tectonic shearing together with high temperature or pressure or both.
- Quartzite is a metamorphic rock. Hence, Option 4 is correct.
  - The original form of Quartzite is pure quartz sandstone.
  - It is formed when quartz-rich sandstone is exposed to high temperatures and pressures.
  - Quartzite is mainly formed through two types of metamorphism namely Contact and Barrovian.

Additional Information

Rocks	Facts
Igneous rocks	Formed due to the cooling, solidification, and crystallization of magma. The common examples of igneous rocks are basalt, gabbro, etc.
Sedimentary rocks	Formed due to the accumulation or deposition of sediments derived from the older rocks, plants, and animals. The common examples of sedimentary rocks are sandstone, conglomerate, etc.
Metamorphic rock	They are formed when existing rocks are changed by heat, pressure, or reactive fluids, such as hot, mineral-laden water. For example, Marble, Quartzite, Schist, etc.

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