Earth Science - Exogenic Processes

Exogenic Processes

• Includes geological phenomena and processes that originate externally/outside to Earth’s surface

• In includes weathering, erosion, and deposition

Weathering

Breaks down of rocks into smaller particles though Physical and Chemical weathering

• Mechanical Weathering

• Chemical Weathering

Weathering:

Mechanical Weathering

The breakdown of rocks into pieces without any change in its composition

• Pressure

• Temperature

• Frost Wedging

• Abrasion

• Root Wedging

• Human Activities

• Burrowing Animals

Mechanical Weathering Factors:

Pressure

When the _______ diminishes, the rock expands, cools, and became brittle and fractured

Temperature

Rocks expand and are fractured when expose to high ___________

Frost Wedging

Generally, rocks have fracture in its surface and when water accumulates in the crack and at that point freezes, he ice expands and breaks the rock apart

Abrasion

The breakdown of rocks is caused by impact and friction

Root Wedging

The roots grow causing penetration into the crack, expand, and in the long run, break the rock

Human Activities

Activities such as digging, quarrying, denuding forests and cultivating land contribute to physical weathering

Burrowing Animals

Animals like rats, rabbits, and squirrels excavate into the ground to create a space for habiation

Chemical Weathering

It is the breakdown of rocks through chemical reactions that change their mineral composition

• Dissolution

• Hydrolysis

• Oxidation

Chemical Reactions:

Dissolution

When water comes into contact with rocks and dissolves the minerals that make up that rock into individual elements

Hydrolysis

Water reacts with minerals in a rock to form new minerals, such as clay

Oxidation

It is the response of oxygen with minerals, iron-rich rocks a rusty-colored weathered surface