WEATHERING What breaks down rocks 1 Erosion process

WEATHERING

What breaks down rocks? 1. Erosion: process of wearing down and carrying away rocks 2. Weathering: breakdown of rock material by physical and chemical processes Erosion works continuously to weather and carry away rocks at Earth’s surface.

Physical Weathering Process by which rock is broken down into smaller pieces by physical changes. Agents of Physical Weathering: 1. Temperature Change 2. Pressure Change 3. Plant and Animal Actions 4. Water 5. Wind 6. Gravity

Temperature Change Frost Wedging: 1. Water seeps into cracks 2. Water freezes into ice 3. The ice expands 4. Ice forces rocks apart Warming and Cooling: Warm/hotter rocks expand, cool rocks contract. Repeating of this causes weak structure and crumbling.

Pressure Change Release of Pressure: erosion removes material from mass of rocks and reduces pressure causing surface of rock to crack and flake ● Exfoliation: process by which outer layers of rock slowly peel away due to pressure changes

Plant and Animal Actions Animal actions: animals burrowing can loosen and break apart rocks in the soil, burrowing exposes more rock Plant growth: 1. Plant roots enter cracks in rocks 2. Roots continue to grow, putting pressure on rock 3. Roots force cracks apart

Wind, Water, and Gravity Abrasion: breaking down and wearing away of rock material by other rock ● Wind: small particles carried and hit against other rock surfaces ● Water: in moving water rocks become rounded and smooth ● Gravity: rocks fall from higher slope and break rocks below

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