Weathering and Erosion

I. Weathering

A. Disintegration is physical weathering; basically making little rocks from big rocks

B. Decomposition is chemical weathering; forming new substances from earth and rock

II. Climate on weathering

A. Decomposition is most rapid when moisture and warmth is present

1. Humic Acid, an acid present in soil with vegetation, speeds decomposition

2. This is common in tropical zones

B. Disintegration is slower and common to temperate zones

1. Freezing and thawing action cracks and breaks rocks

III. Products of weathering

A. Include rock fragments and chemically altered sediments

1. Sediments include;

· clay

· lime

· quartz

IV. Erosion

A. Redeposting of weathered products

1. “scouring” the earth’s surface with agents that are always in motion