Geomorphic Processes

The word 'sedimentary' is derived from the Latin word 'sedimentum', which means 'settle down'. This refers to how loose particles settle at the bottom of water bodies or land surfaces to eventually form rock layers.

Mechanical (or physical) weathering is the process of breaking big rocks into smaller pieces through physical forces like wind, water, or ice, without changing the chemical composition of the rock.

Erosion is the process by which weathered rock and soil particles are moved from one place to another. Ocean waves carrying sand away from the coastline is a clear example of this transport process.

Weathering is the physical or chemical breakdown of rocks into smaller fragments at Earth's surface. A river current wearing down and breaking apart rock in a canyon represents weathering, whereas carrying those pieces away would be erosion.

Limestone is composed of calcium carbonate, which dissolves when it reacts with acidic groundwater. This dissolution is a form of chemical weathering that creates large underground cavities over time. Mechanical weathering, by contrast, only breaks rocks physically without changing their chemical composition.

Soil is primarily composed of tiny rock particles, organic matter, water, and air. Weathering breaks down larger rocks into smaller fragments and sediment, which serves as the foundational mineral component of soil. Without this breakdown of rock, soil cannot develop.

Mechanical weathering physically breaks rocks into smaller pieces without altering their mineral composition. In contrast, chemical weathering involves chemical reactions that transform the minerals within the rock into new substances.

The structure 'caused [something] to' must be followed by the base form of a verb. 'Erode' is the correct verb form here. 'Erosion' and 'evaporation' are nouns, and 'evaporate' does not make sense in the context of a valley and a glacier.

Coastal cliffs collapse primarily because waves erode the base of the cliff, creating a wave-cut notch. Over time, the lack of support causes the overhanging cliff to collapse under gravity.

Erosion is the geological process in which earthen materials are worn away and transported by natural forces such as wind or water. Option D provides the standard scientific definition of this process.

Desertification is the process by which fertile land becomes desert, typically as a result of drought, deforestation, or inappropriate agriculture. Defertilization is not a standard term for this process, and barren land is a state rather than a process.

Erosion is the geological process in which earth materials are worn away and transported by natural forces such as wind, water, ice, or gravity. In contrast, weathering is the static breaking down of rocks, while oxidation is a specific chemical reaction. Because the question specifies the removal and transport of particles, erosion is the correct term.

Acid rain is a classic example of chemical weathering because it involves a chemical reaction between acidic water and minerals in rocks, causing them to dissolve or alter. Freezing, thawing, and pressure are physical processes that mechanically break rocks apart without changing their chemical composition. Therefore, acid rain is the only chemical process listed.

Freezing and thawing (frost wedging) physically breaks rocks apart without changing their chemical composition, making it a mechanical weathering agent. Carbon dioxide, acid rain, and oxygen cause chemical weathering by reacting with minerals in the rock.

Liquefaction occurs when saturated soil loses its strength and stiffness in response to earthquake shaking, causing it to behave like a liquid.