Earth's Geological Cycles Flashcards

Which geological process causes rocks to break down into smaller particles at Earth's surface?

Answer: Weathering

Weathering is the physical and chemical breakdown of rocks at or near Earth's surface into smaller fragments and minerals.

In the nitrogen cycle, which process converts atmospheric nitrogen gas into a form usable by plants?

Answer: Nitrogen fixation

Nitrogen fixation converts N₂ gas into ammonia or nitrates, primarily through bacteria in soil and plant root nodules.

What term describes the process by which sediments are compacted and cemented together to form sedimentary rock?

Answer: Lithification

Lithification is the process by which loose sediments are compacted by pressure and cemented by minerals to form solid sedimentary rock.

Which part of the rock cycle occurs when rocks are exposed to high heat and pressure without melting?

Answer: Metamorphism

Metamorphism transforms existing rocks through heat and pressure into metamorphic rocks without the rock melting completely.

What is the term for water that flows over Earth's surface and eventually enters rivers and streams?

Answer: Runoff

Runoff is precipitation that flows over land into rivers, lakes, and eventually the ocean rather than soaking into the ground.

Which type of volcano typically forms at hot spots unrelated to tectonic plate boundaries?

Answer: Shield volcano

Shield volcanoes, like those in Hawaii, form over hot spots and are characterized by low-viscosity lava flows that build broad, gently sloping structures.

In the carbon cycle, which natural process releases CO₂ back into the atmosphere?

Answer: Cellular respiration

Cellular respiration in living organisms breaks down organic compounds and releases carbon dioxide back into the atmosphere.