October 2, 2012Warm Up:

Finish coloring and homework comics.

Turn in Homework to the bin.

Today:

• We will explain the changes on Earth’s surface and be able to determine how rocks provide valuable information about Earth’s crust.

• You will work with a partner to describe, explain and identify various examples of how Earth’s surface changes through natural and chemical processes.

The Basics…• WEATHERING: The breakdown of rocks

• MECHANICAL weathering = the natural and physical breakdown of rock

• CHEMICAL weathering = the breakdown of rock by chemical reactions – Acid precipitation

MECHANICAL WEATHERING• Erosion: Movement of sediment by wind, water, glaciers and gravity

• WATER! Major agent of erosion– Rivers– Oceans

• Freeze/Thaw: water freezes and expands, thaws and rocks break apart

• Plants: roots may grow into tiny cracks in rocks and exert force, breaking the rock

Test It…• You will see a series of pictures. • One partner will look at the picture and describe it to

his/her partner. • The partner will write down what Earth process they

believe is represented by the picture. *NOT giving answers here!– IE: erosion by water; chemical weathering; etc…

• Then, partners switch positions. Repeat!• I will reward the partnership with the most correct

answers!

PARTNERS SWITCH!

Were You Right?!

EROSION BY WATER

CHEMICAL WEATHERING

EROSION BY WATER

MECHANICAL BY FREEZE-THAW

MECHANICAL BY PLANTS

EROSION BY WIND

EROSION BY WIND

EROSION BY WATER

EROSION BY WATER

MEHCANICAL BY PLANTS

CHEMICAL WEATHERING

MEHCANICAL BY FREEZE-THAW

Game• 3 teams of 7• You will relay breaking down the landform

(weathering), carry it across crab-style (erosion), deposit to make another landform (deposition)

• First team finished wins!!

Be prepared for a quiz on rocks and Weathering tomorrow!!