EROSION

WATER EROSION WATER FLOW-wearing down of rocks in a river

ABRASION- wearing down the banks of a river

DELTAS are formed where the sediment from a river reaches its mouth

DISSOLVING- wearing down the chemical elements in the rock

WAVE ACTION- reducing or increasing beaches

WIND EROSION WIND-BLOWN SILT AND CLAY IS CALLED LOESS. IT IS VERY FERTILE.

A LOESS HILL IN IOWA LOESS PLAINS IN CHINA

GLACIAL EROSION Glaciers move as rivers of ice, carrying soil and crushing rocks. They change the landscape, forming ridges and hollowing out lakes.

MORAINE- rocks left behind by a glacier

Weathering and Erosion Review xk

Weathering What is weathering? It produces: 1.SEDIMENT 2.MUD 3.SAND 4.SILT

OF WEATHERING Mechanical weathering- changes only the size of rock WHAT ARE SOME EXAMPLES?

CHEMICAL WEATHERING Changes rock into a new substance by interacting with air or water Examples? Acid Rain, stalagmites and stalactites in a cave

BUILDING SOIL WEATHERING AND EROSION FORM SOIL BY BREAKING UP ROCK.

Soil: One of our most precious resources What happens when we lose our soil?

HUMUS- the amount of organic material in soil The more humus, the more fertile the soil.

SOIL FACTORS PARENT MATERIAL- the composition of the original rock RELIEF- steeper slopes do not produce soil as quickly ORGANISMS- amount of nutrients from small plants and animals in the soil CLIMATE- soils from wet, dry, cold, and hot regions are different TIME- It takes 100 years to produce 2.5 CUBIC CENTIMETERS of soil (about the size of your fingertip)

Lessons from the Dust Bowl The Ogalalla Aquifer