Weathering and Soil Formation

Flashcards covering key concepts from the lecture on weathering and soil formation.

Weathering

The process that breaks down rocks and minerals, necessary for soil formation.

Soil

An interface where the geosphere, biosphere, atmosphere, and hydrosphere interact.

Leaching

The process by which water removes dissolved ions and fine-grained materials from the soil.

Humus

Organic matter in soil produced by the decomposition of plants and animals.

O Horizon

The uppermost soil horizon composed primarily of organic material.

A Horizon

The layer beneath the O horizon, rich in humus and mineral matter.

E Horizon

A layer characterized by leaching and lighter in color due to lack of organic material.

B Horizon

The subsoil layer that accumulates minerals and nutrients leached from above.

C Horizon

Material that has been chemically weathered but not leached or accumulated, acting as a transition to bedrock.

Soil Horizons

Distinct layers in soil profiles that form due to various processes occurring at different depths.

Soil Erosion

The removal of the top layer of soil, often accelerated by human activities.

Dust Bowl

An ecological disaster in the 1930s caused by poor agricultural practices leading to major soil erosion.

Pedogenesis

The process of soil formation that includes weathering, biological activity, and leaching.

Biological Activity

The interactions of organisms like plants, microbes, and animals that contribute to soil formation and health.

Mollisol

A soil type that develops in grasslands, rich in nutrients and organic material.

Alfisol

Soil that develops under deciduous forests, characterized by a clay-rich horizon.

Gelisols

Young, thin soils found in polar regions, often associated with permafrost.

Chemical weathering

The process where rocks are broken down by chemical reactions, essential for soil development.

Physical weathering

The mechanical breakdown of rocks without chemical change, facilitating soil formation.

Microbial Metabolism

Processes by which microbes break down organic matter, releasing nutrients back into the soil.

Substrate

The underlying rock or material from which soil develops.