Weathering and Mass movements quiz

Weathering

The chemical and physical breakdown of rocks on or at the Earth’s surface into smaller fragments.

Erosion

The movement of weathered material from one place to another.

Weathering agents

Factors that change the physical and/or chemical characteristics of the rocks.

Physical weathering

Occurs when a rock is cracked, split, or broken into smaller pieces called sediments, with no change in rock composition.

Sediments

Classified by size as boulders, cobbles, pebbles, sand, silt, clays, and dissolved particles.

Frost action

The breakup of rocks caused by alternate freezing and thawing of water.

Abrasion

The physical wearing down of rocks as they rub or bounce against each other.

Exfoliation

Peeling away large sheets of loosened material at the surface of a rock.

Root wedging

Occurs when large shrubs grow through cracks in boulders, potentially breaking the rock apart.

Chemical weathering

Occurs when a rock is broken down by chemical action, resulting in a change in the composition of the rock.

Oxidation

Occurs when oxygen chemically unites with minerals, often forming rust (iron oxide).

Hydration

When water unites chemically with minerals, causing certain minerals to crumble into small particles of clay.

Carbonation

When carbon dioxide unites chemically with minerals, forming weak carbonic acid that dissolves limestone.

Acid Precipitation

Comes from acids mixed with rain or snow, often resulting from the burning of fossil fuels.

Groundwater

Contains weak acids which help to dissolve some kinds of rocks.

Sinkholes

Saucer-shaped holes in the land surface formed when carbonic acid dissolves limestone.

Karst topography

A limestone area characterized by pitted terrain and sinkholes.

Stalactites

Icicle-shaped limestone deposits that hang from the ceiling of caves.

Stalagmites

Deposits that grow up from the ground in a cave.

Organic decay

Occurs when acids formed from decaying plants and animals dissolve in water.

Soil

The part of weathered regolith in which rooted plants grow, composed of rock particles, minerals, and organic matter.

Particle size

Refers to how the weathering rate of rock material varies inversely with particle size.

Mineral Composition

Indicates that rock particles weather at different rates based on their mineral composition.

Transported sediment

Rock material that has been moved from its place of origin to another location.

Residual sediment

Rock material that has weathered and remained in its place of origin.

Transporting agents

Forces that move sediments from one place to another.

Mass movement

When Earth materials move downslope under the influence of gravity.

Gravity

The primary driving force behind all transporting (erosional) systems.

Soil Profile

The series of layers developed in soil as it matures, each with different textures and colors.

Topsoil

The top layer of soil, rich in organic matter and ideal for plant growth.

Subsoil

The layer of soil located under the topsoil, rich in clay-sized particles.