Teacher resources and professional development across the curriculum

Teacher professional development and classroom resources across the curriculum

 Choose One Interactives Home Math Interactives -Geometry 3D Shapes Language Interactives -Elements of a Story -Historical and Cultural -Spelling Bee Arts History Interactives -Middle Ages -Renaissance -U.S. History Map Science Interactives -Amusement Park Physics -Dynamic Earth -Ecology Lab -Periodic Table -Rock Cycle -Volcanoes

# How Rocks Change

## Weathering & Erosion

What do dandelions rely on to separate their seeds, carry them, and deposit them elsewhere? The wind.

All objects on the earth's surface are exposed to the wind, along with many other elements — water, the sun, temperature changes. Over time, these factors wear objects down and break them apart. The resulting bits and pieces of material are called sediment. Sediment is then transported by wind and water, often ending up far from where it started. These processes of breakdown and transport due to exposure to the environment are called weathering and erosion. Weathering and erosion affect all rocks on the earth's surface.

## Compacting & Cementing

What happens to a loose pile of garbage when it's put into a compactor? The squeezing of the machine produces a solid cube of compacted garbage.

The same thing happens to sediment formed from the weathering and erosion of rock. Over time, sediment accumulates in oceans, lakes, and valleys, eventually building up in layers and weighing down the material underneath. This weight presses the sediment particles together, compacting them. Water passing through the spaces in between the particles helps to cement them together even more. This process of compacting and cementing sediment forms sedimentary rock.

 Transform the RockTransform the RockSee if you can identify the processes that can change rocks from type to another.