 Weathering is the process by which rocks break down and change  Mechanical  Chemical

 Mechanical(Physical) Weathering is the process where rocks break into smaller pieces with no change in their composition  Caused by:  Cold temperatures  Tectonic Processes  Biological Activity

 Frost Wedging-The repeated thawing and freezing of water in the cracks of rocks  Water expands when frozen, chips away parts of the rock

 Unloading occurs when igneous rock becomes exposed through uplift and erosion  Exfoliation-Occurs when pieces of the uplifted rock are weathered and chipped away

 Organisms can cause Mechanical Weathering  Plant roots growing into cracks in rocks  Burrowing animals moving rocks  Decayed animals can produce acids (Chemical Weathering)

 Chemical Weathering- Rocks undergo changes in their composition  Caused by:  Water  Oxygen  Carbon Dioxide  Acids

 Hydrolysis-The reaction of water with other substances  Oxidation-The reaction of oxygen with other substances

 Water causes Chemical Weathering by absorbing gases from the atmosphere and ground  CO 2 +Water  Carbonic Acid ▪ Dissolves Rocks/Minerals ▪ Stalactites/Stalagmites

 Differential weathering is when rocks weather at different rates  Caused by different mineral compositions  Sedimentary rocks weather more easily than igneous rocks

 The statue of liberty is made of copper which is generally a brownish color  Has been affected by chemical weathering  Water reacting with the copper  Sulfuric acid formed by pollution (debatable)