Describe how three processes act together to wear down and build up Earths surface

Chapter 3 Lesson 1 Rocks and Weathering

Benchmarks: SC.6.N.3.4- Identify the role of models in the context of the benchmarks. SC.6.E.6.1- Describe and give examples of ways in which Earth’s surface is built up and torn down by weathering, erosion, and deposition.

Vocabulary Weathering Erosion Sediment Deposition Physical weathering Chemical weathering Abrasion Frost wedging Oxidation Permeable

Processes that Wear down and Build up Earth’s Surface Natural processes break down rocks and carry pieces away. Weathering- the process that breaks down rock and other substances. Once rock is broken down, the smaller pieces can be carried away by wind, water, ice, or gravity.

Weathering and Erosion Study Jams Erosion- the process by which bits of broken rock are carried away. Erosion moves sediment- small pieces of rock , soil, remains of plant or remains of animals. Deposition- occurs where the sediment is laid down, or deposited. Final place where sediment is moved. Weathering and Erosion Study Jams

Weathering and Erosion Cycle

Weathering, Erosion, & Deposition WEATHERING, EROSION, AND DEPOSITION act together in a cycle that wears down and builds up Earth’s surface. Weathering- breaks down the Earth and Erosion and Deposition build up the Earth’s surface. The cycle is never ending.

Two types of Weathering: Physical and Chemical Physical Weathering- rock is physically broken into smaller pieces. Animal Actions Freezing and Thawing Plant Growth Release Pressure Abrasion Chemical Weathering- process that breaks down rock through chemical changes. 1- Water 2- oxygen 3- carbon dioxide 4-living organisms 5- acid rain

5 agents of Physical Weathering

5 Agents of Chemical Weathering Water: can weather rocks by dissolving & changing the make up. O2: mixes with water to make rust. This gives some rocks a rust colored look. CO2: with water makes an acid that eats away at limestone. Can cause sinkholes!!! Living organisms: plants’ roots produce a weak acid. Acid rain: from pollution in atm mixes in water cycle & produces a strong acid.

How fast does weathering occur? 2 factors determine how fast weathering occurs… 1. Type of Rock- if rocks are made of materials that dissolve easily will weather faster. If rocks are permeable, full of tiny holes where water can seep into it, they will also weather faster. 2. Climate- Physical and chemical weathering occur faster in wet and hot climates.

Chapter 3 Lesson 1 Review

Chapter 3 Lesson 3 Mass Movement What are the different types of mass movements? Weathering, Erosion and Deposition- tear down and build up the Earth. Once cracks in rock from, the rock has a tendency to fall apart… What makes the land/rock fall apart? GRAVITY

What is Gravity? Gravity is the force that pulls everything toward the center of the Earth. It pulls rock down slopes, it can cause sections of rock to fall off cliffs, it can also cause movement of large amounts of sediment.

Mass Movement Is any one of several processes that move large amounts of sediment downhill. There are 4 types of mass movements: 1- Landslides 2-Mudflows 3- Slumps 4- Creep

Landslides: Landslides occur when rock and soil slide quickly down a steep slope. They contain a small amount of rock or soil.

Mudflows Mudflows- is the rapid downhill movement of a mixture of water, rock, and soil. They often occur after heavy rains in normally dry areas.

Slumps Slumps are masses of rock and soil that suddenly slips down a slope. The mass moves down in one whole piece. They occur in soil high in clay.

Creep Creep- a very slow downhill movement of rock and soil. It can occur on gently slopes as well. Creep are usually caused be freezing and thawing.

Match the diagram with the mass movement 1- Landslides 2-Mudflows 3- Slumps 4- Creep

Mass Movement Review

Weathering, erosion, and deposition are processes that act together to wear down and build up the Earth's surface.  These processes have occurred over billions of years.

Weathering is any process that breaks down rocks and creates sediments.  There are two forces of weathering, chemical and mechanical (physical).

• Chemical weathering is decomposition of rock caused by chemical reactions resulting in formation of new compound.
• Mechanical (physical) weathering is the breakdown of rock into smaller pieces.  

Erosion is the process by which natural forces move weathered rock and soil from one place to another.  Gravity, running water, glaciers, waves, and wind all cause erosion.  The material moved by erosion is sediment.

Deposition occurs when the agents (wind or water) of erosion lay down sediment.  Deposition changes the shape of the land.

Erosion, weathering, and deposition are at work everywhere on Earth.  Gravity pulls everything toward the center of Earth causing rock and other materials to move downhill.  Water's movements (both on land and underground) cause weathering and erosion, which change the land's surface features and create underground formations.  

The effects of these processes are as follows:

• Changes in shape, size, and texture of land-forms (i.e. mountains, riverbeds, and beaches)
• Landslides
• Buildings, statues, and roads wearing away
• Soil formation
• Washes soil, pollutants, harmful sediments into waterways
• Causes metals to rust
• Reduces beaches, shorelines
• Delta formation
• Formation of various new landforms