Weathering

The weathering is the process of disintegration and separation of rocks that happens when they contact with the atmosphere. 

• Mechanical or physical weathering: The fragmentation of rocks in smaller pieces, that still have the characteristics of the original material. They are held in extremely climates (very cold or very warm). 

• Gelifraction: Is the break of a rock because of the action of water. The water is deposited in the cracks, and when it's frozen, the water freezes. The volume increase, and there is no enough space. The water makes strength, and breaks the rock.

• Pedrizas: 

• Scree:
  

• Haloclasty: Is the breaking of rocks by the action of the salt. In some places there is salt, and then the rain wash the ground, taking the salt. The salt get inside of the rocks, and then it recrystallization and increase the volume. That break the rock in very angular and smaller rocks. 
  

• Thermoclasty: Is the break of a rock because of temperature changes. In the morning, when heated, the rock expanded. At night, when it cooled, it contracts. After a while, they break. 
  

• Biological: The rock split because of natural elements. For example, if a tree sprout in the crack of a rock, when it grow up, it will break the rock. It can happen because of the action of living organisms when they build their burrows.
  

• Chemical weathering: There's a process that change the composition of the rock, and not only the appearance. It usually happen in wetlands. The more humidity there is, bigger is the intensity of the weathering.
  

• Melting: It happen when there's a rainfall, the water falls down the slopes and ridges are created. 

• Limestone pavement: 
  

• Carbonation: The carbonic acid combined with minerals form bicarbonate: one is insoluble in water but the second is not, so is driven by it. The opposite process is the decarbonation: water takes calcium bicarbonate that become solidified in calcium carbonate. 
  

• Silvina: Easy dilution.
  

• Halite: Common salt. 
  

• Hydration: The water is incorporated into the structure of some rocks and increase the volume. When the water disappear, the rock contract creating cracks. It usually happen in the clays. 
  

• Oxidation: It happen when the materials react with the oxygen, and change the composition of the materials. In this process, the colour changes to ochre.  
  

• Biological: The cause of the weathering are the animals, plants or humans. Lichens are an example. They just grow with the this that are in the atmosphere. They expel a chemical substance that dissolve the rock. There are four horizons of the soil:

• It is form by leaves and organic waste and partially decomposed waste. The colour is darker than other places because of the materials. 

• Precipitation of substances washed. 

• Fragments and remains of weathering of bedrock. 

• The bedrock.