Rivers and Mountains

By Gianna, Garrett, Costel, and Sabrina

Weathering and Erosion

• Weathering and erosion change the shape of mountains over time.

• Weathering is a process by which rock is broken up into smaller pieces.

• Weathering and erosion slowly chisels, polishes, and buffs Earth’s rock into ever evolving works of art.

• Weathering wears down rock by flowing over it.

Mountain Erosion

• Old mountain ranges are eroded flat. However, there are also forces creating new mountains. For example, the Himalayas are still rising.

• Present rates of erosion are particularly high due to more mountain building and higher mountains than usual in earth’s history.

• The reasoning behind this claim directly contradicts the reasoning behind the claim that volcanoes build too much material for an old earth.

Facts About River Erosion

• Rivers usually start out as mountain streams.• Mature rivers flow across wide river valleys

and meander or snakes across the flat plains. These meandering streams create large loop meanders that develop into oxbow lakes and adjacent to the stream.

Can Natural Disasters Affect River Erosion?

• Yes, erosion explains how rivers form. When rain falls, they cut through sediment and even rock to form channels where water can flow more freely. The path eventually becomes more pronounced, making a path, which other raindrops can follow. Over long periods of time, erosion continues to do this to form waterways.

How do Rivers and Mountains Change the Earth’s Surface?

• Rivers erode material from one place, and then it deposits that material in another place.

• Mountains change the earth’s surface because they form when two plate tectonics collide into each other, which is called the convergent boundary.

The Results of Too Much Weathering and Erosion

• If there was too much erosion, rivers would overflow and cause floods. This would disturb and damage people’s homes.

• If there was too much weathering, there wouldn’t be any mountains, and there would be lots of flatlands on earth.

Questions

• Does Weathering and Erosion change the shape of mountains?

• What is the process of Weathering and Erosion?

• What does weathering do?

Answers

• Yes, because Weathering wears down mountains to water level.

• Weathering wears down rocks into small particles over time, and erosion moves the small particles around.

• Weathering buffs Earth’s rock into ever evolving works of art, and wears down rock by flowing over it.

Resources

• http://www.google.com• http://www.easybib.com/cite/view• http://www.wiki.answers.com/