The name orthoquartzite is used for a sedimentary rock of similar composition but having different origin, in which quartz grains are cemented toger by siliceous cement.

Rocks situated near plate boundaries or within geosynclinal belts are especially prone to directed pressure and often show severest degree of metamorphic changes.

The sedimentary rocks under chemically formed deposits are Siliceous deposits, carbonate deposits, ferruginous, phosphatic and evaporites.

The correct answer is Granite.

Key Points

• Igneous rocks are most basic type of rocks. They are formed when magma (molten rock, typically derived from earth's mantle) solidifies.
• This can happen beneath or above surface, resulting in 2 subtypes:
  • Plutonic rocks
  • Volcanic rocks
• Plutonic rocks: 
  • When magma never reaches surface and cools to form intrusions (dykes, sills, etc) resulting rocks are called plutonic.
  • Granite is an example of Plutonic rock.
• Volcanic rocks: 
  • When magma does reach surface during a volcanic eruption, rocks that form re are called lavas or volcanic rocks.
• Sedimentary rocks: 
  • Rocks that are formed by consolidation of sediments of Pre-existing rocks under mechanical, chemical, or organic activities of wind, running water, etc are sedimentary rocks.
• Metamorphic rocks: 
  • Rocks that are formed under influence of heat, pressure or both from pre-existing rocks are called Metamorphic rocks.

Maculose structure is characterized by a spotted appearance of rock that may be caused due to formation of large-sized crystals called porphyroblasts within an orwise fine grained rock.

Slate is an extremely fine-grained metamorphic rock characterized by a slaty cleavage by virtue of which it can be readily split into thin sheets having parallel smooth surfaces.

Shale is a finely-grained sedimentary rock of argillaceous composition. Shales are generally characterized with a distinct fissility (parting) parallel to bedding planes.

Pneumatolytic is process of metasomatism where fluids are in form of gases or vapours.

High grade schists are formed under conditions of regional metamorphism and atoms rich in minerals that are stable at high temperatures such as garnet.

Limestones are most common sedimentary rocks from non-clastic group and are composed chiefly of carbonate of calcium with subordinate proportions of carbonate of magnesium.