Rocks & Minerals — Set 5
Geography · चट्टानें और खनिज · Questions 41–50 of 50
The liquid molten rock that flows out of a volcano is called?
Correct Answer: B. Lava
Lava is molten rock that has been expelled from the interior of a terrestrial planet. It flows on the surface during volcanic eruptions. As it cools, it solidifies into extrusive igneous rock.
Intrusive igneous rocks that form deep underground are also known as?
Correct Answer: D. Plutonic rocks
Intrusive igneous rocks are also called Plutonic rocks, named after Pluto, the Roman god of the underworld. These rocks cool slowly at great depths. Granite is the most common example.
Stratification (layering) is a key characteristic of which rock type?
Correct Answer: C. Sedimentary
Sedimentary rocks are typically deposited in layers known as strata or beds. This stratification occurs as new sediment is deposited on top of older layers over time. It is a distinctive feature separating them from massive igneous rocks.
Petroleum and natural gas are typically found in which type of rock?
Correct Answer: D. Sedimentary
Petroleum and natural gas are found in sedimentary rocks like sandstone and limestone. The porous nature of these rocks allows them to store hydrocarbons. These fuels originate from ancient organic matter trapped in the sediment.
Slate is a metamorphic rock derived from which sedimentary rock?
Correct Answer: D. Shale
Slate forms from the low-grade metamorphism of shale or mudstone. The pressure aligns the microscopic clay minerals, creating distinct cleavage planes. This allows slate to be split into thin, durable roofing tiles.
Granite is the most common example of which major rock category?
Correct Answer: B. Igneous
Granite is the quintessential intrusive igneous rock. It forms from the slow cooling of magma beneath the Earth's surface. It is composed mainly of quartz, feldspar, and mica.
Basalt is the most common example of which major rock category?
Correct Answer: D. Igneous
Basalt is the most common extrusive igneous rock. It makes up most of the ocean floor and large volcanic provinces on land. It forms from the rapid cooling of low-viscosity lava.
Marble is a metamorphic version of which rock?
Correct Answer: C. Limestone
Marble is the metamorphic product of limestone or dolostone. Heat and pressure cause the calcium carbonate to recrystallize. This process destroys any fossils present in the original limestone.
Which of these is a sedimentary rock often used in making cement?
Correct Answer: D. Limestone
Limestone is a sedimentary rock composed largely of calcium carbonate. It is the primary raw material used in the manufacturing of cement. It is also used as a building stone and in road construction.
What are the two main agents responsible for Metamorphism?
Correct Answer: D. Heat and Pressure
Metamorphism is driven primarily by intense heat and high pressure. Heat softens the rock, while pressure realigns minerals or forces recrystallization. Chemically active fluids can also play a role in the changes.