Processes of chemical weathering typical of glacial environments

Question 1

Describe the process of oxidation?

Answer 1

Some minerals in rocks react with oxygen, either in the air or in water, iron is especially susceptible to this process. It become soluble under extremely acidic conditions and the original structure is destroyed. It often attacks the iron-rich cements that bind sand grains together in sandstone.

Question 2

Describe the process of carbonation?

Answer 2

Rainwater combines with dissolved carbon dioxide from the atmosphere to produce a weak-carbonic acid. This reacts with calcium carbonate in rocks such as limestone to produce calcium bicarbonate, which is soluble. This process is reversable and precipitation of calcite happens during evaporation of calcium-rich water in caves to form stalactites and stalagmites.

Question 3

Describe the process of solution?

Answer 3

Some salts are soluble in water. Other minerals, such as iron, are only soluble in very acidic water, with a PH of about 3. Any process by which a mineral dissolves in water is known as solution, although mineral-specific processes, such as carbonation, can be identified.

Question 4

Describe the process of hydrolysis?

Answer 4

There is a chemical reaction between rock minerals and water. Silicates combine with water, producing secondary minerals such as clays. Feldspar in granite reacts with hydrogen in water to produce kaolin (china clay).

Question 5

Describe the process of hydration?

Answer 5

Water molecules added to rock minerals create new minerals of a larger volume. This happens to anhydrite, forming gypsum. Hydration causes surface flaking in many rocks, partly because some minerals also expand by about 0.5% during the chemical change as well because they absorb water.