Weathering and Erosion Unit: Earth and Space Science

The physical breakdown (disintegration) and the chemical alteration (decomposition) of rock due to combined action of all processes.

Weathering

What are the two forms of weathering?

Physical and Chemical

The breakdown of rocks and minerals through chemical reactions, often involving water, gases, and biological activity. The changes in the mineral composition sometimes form new minerals.

Chemical Weathering

What are the 4 key agents in Chemical Weathering?

Water, Oxygen, Carbon Dioxide, Organic Acids

The transformation of minerals by chemically breaking them down with water, altering their structure and creating new, often more stable, substances like clay.

Hydrolysis

What does hydrolysis do to minerals?

dissolve ions and break them down

A reaction process that weakens the rock structure, alters mineral composition, and forms new minerals like iron oxides, which contribute to rust-like colors and soil development.

Oxidation

The process where water reacts with carbon dioxide to form carbonic acid which then reacts rocks and minerals and breaks them down.

Carbonation

True or False: Carbonic Acid and Hydrolysis are the same thing

False

True or False: Hydrolysis breaks compounds by reacting them directly with water, while carbonation involves the chemical reaction of water with carbon dioxide to form carbonic acid, which then reacts with other substances

True

The process where roots, lichens, and microbes release weak acids that enhance chemical weathering.

Biological Activities

Which mineral is extremely resistant to chemical weathering?

Quartz

Which mineral is most commonly found in sand?

Quartz

The process where rocks break down into fragments that are smaller, but atomically the same as the parent rock.

Mechanical (Physical) Weathering

What are the 6 key agents of mechanical weathering?

Ice, plants, animals, gravity, running water wind

A process where water fills in cracks within an object, freezes and expands, and splits the object further.

Ice Wedging

A process where overlying material is removed due to erosion. The rock gets weak points, expands, and the outer layer of rock peels of in sheets.

Exfoliation

A process where rocks grind against each other (by wind, glaciers, water, or gravity) and and cause rounding and smoothing of rock surfaces.

Abrasion

What process is animals burrowing and plant roots growing an example of?

Biological Activities

The process where weathered rock is transported.

Erosion

Wearing away of the fertile topsoil

Soil Erosion

4 agents of Soil Erosion

Water, Wind, Ice, and Human Activities

Consequences of Soil Erosion

Loss of fertile soil, desertification, loss of biodiversity

Weathered rock and mineral particles with a granular size of 0.0645 mm to 2 mm and are primarily composed of quartz.

Sand

How is sand formed?

Weathering and Erosion

A combination of mineral matter, organic matter, water, and air

Soil

What are the four types of soil?

Clay, Sand, Silt, Loam

Rocks weather and are mixed with layers of organic matter over time. 

How is soil formed?

What holds soil?

Plant Roots

What create air passages and lift minerals up in soil?

Worms

What adds nutrients to soil?

Plants

What is the uppermost layer of soil? It is a dark soil made of mostly loose and partly decayed organic matter and mineral matter mixed with humus. (O-A Horizon)

Top Soil

What is the second uppermost layer of soil? It is light soil made of mostly weathered materials from the above layer and an accumulation of clay transported from above. (E and B Horizon)

Subsoil

What is the third layer of the soil? It is partially altered parent material, and is also the C horizon.

Gradational boundary

What is the deepest layer in soil?

Bedrock (Parent Rock)

What control the soil formation? (5)

Parent Rock, Time, Climate, Topography, Vegetation

White sandy beaches are often made of:

1.) Basalt Fragments

2.) Volcanic Glass
3.) Quartz and Feldspar

4.) Shells and Coral Pieces (Calcium Carbonate)

(This one is important as I got it wrong on the quiz)

Shells and Corals (Calcium Carbonate)

Which of these is NOT an agent of erosion?

1.) Water

2.) Plants

3.) Wind

4.) Ice

Plants

A delta forms where:

1.) Wind deposits sand

2.) A glacier melts

3.) A mountain erodes

4.) A river meets the ocean or lake and slows down

A river meets the ocean or lake and slows down

Black sand beaches as shown in the picture usually form from:

1.) Volcanic lava (basalt)

2.) Weathered granite

3.) Shells and coral

4.) Desert dunes

Volcanic Lava (basalt)

What formed the Grand Canyon?

The Colorado River

What forms Fjords?

Receded Glaciers