Earth Systems and Resources: Soil Formation and Composition

This set of flashcards covers vocabulary related to soil formation, types of rocks, weathering, erosion, and properties that affect soil productivity.

Igneous Rock

A type of rock formed directly from molten magma.

Sedimentary Rock

Rocks formed from compressed sediments over time.

Metamorphic Rock

Rocks formed when sedimentary, igneous, or other metamorphic rocks undergo high temperatures and pressures.

Magma

The original source of all rock, molten material from which igneous rocks are formed.

Weathering

The process of breaking down rocks by exposure to air, water, chemical compounds, or biological agents.

Erosion

The physical removal of rock fragments from a landscape or ecosystem.

Physical Weathering

The mechanical breakdown of rocks and minerals due to factors like water, wind, or temperature changes.

Chemical Weathering

The breakdown of rocks and minerals by chemical reactions.

Soil Horizons

Distinct horizontal layers in fully formed soils, each with unique physical features.

O Horizon

The organic layer at the surface of the soil, containing decomposed organic matter.

A Horizon

The topsoil layer, comprised of organic material mixed with minerals.

B Horizon

The subsoil layer, primarily made up of mineral material with little organic matter.

C Horizon

The least weathered layer of soil, similar to the parent material.

Detritus

Accumulated organic materials resulting from the decomposition of plants and animals.

Cation Exchange Capacity (CEC)

The ability of soil to adsorb and release positively charged mineral ions.

Base Saturation

The proportion of soil bases to soil acids, affecting plant nutrition.

Soil Productivity

The capability of soil to support plant growth, influenced by physical, chemical, and biological properties.