Weathering, Erosion, and Deposition

Weathering Weathering is the process that breaks down and changes rocks. It can be caused by air, ice, water, chemicals, and living things.

Two Types of Weathering Physical Weathering: When rocks are broken apart, but it doesn’t change what the rocks are made of. Size and shape may change but it’s still the same type of rock/material.

An Example of Physical Weathering of Rock

Two Types of Weathering Chemical Weathering: When a chemical change is made in the material of the rock. Example: iron in rock may change to iron oxide (rust) as a chemical change. Water and air pollution can cause chemical weathering.

An Example of Chemical Weathering of Rock: Water Dissolves Limestone

Erosion The process of moving weathered rock and soil by the wind, water, and ice is called erosion. Water is the main cause of erosion. Fast-flowing water can erode soil and small rocks from the banks of streams and rivers.

Erosion on Shorelines: Waves crash against the beach, and they carry away large quantities of sand and small rocks quickly. Wind can carry sand and soil away, as well.

Erosion on a Shoreline

Deposition The dropping of materials moved by erosion is called deposition.

Deposition and Sand Dunes When wind carrying sand from a beach is slowed down by an obstacle, it deposits the sand. Over time, the process is repeated, resulting in a mound of sand. The mound slows the wind further, eventually depositing a large dune.

Sand Dune formed by deposition

Deposition and Beaches Waves can make new land by eroding sand and rock and then carrying sand toward land until it reaches the shores of a bay where the waves move more slowly. The sand is deposited, forming new beaches.

Let’s Compare! Contrast the effects of deposition and erosion on shorelines. What’s different?

Let’s Compare! Deposition of sand by waves creates or increases the size of beaches along shorelines. Erosion of sand by waves destroys or reduces the sizes of beaches along shorelines.

Can You Answer the Following Questions Correctly?

Chemical weatheringErosion DepositionDune ErosionMoving water Physical weatheringWeathering

Chemical weatheringErosion DepositionDune ErosionMoving water Physical weatheringWeathering

Chemical weatheringErosion DepositionDune ErosionMoving water Physical weatheringWeathering

Chemical weatheringErosion DepositionDune ErosionMoving water Physical weatheringWeathering

Chemical weatheringErosion DepositionDune ErosionMoving water Physical weatheringWeathering

Chemical weatheringErosion DepositionDune ErosionMoving water Physical weatheringWeathering

Chemical weatheringErosion DepositionDune ErosionMoving water Physical weatheringWeathering

Chemical weatheringErosion DepositionDune ErosionMoving water Physical weatheringWeathering