weathering

• freeze/thaw: mechanical weathering, occurs in snow covered mountain ranges such as the Alps, it’s the break up of rock by frost action
• freeze/thaw: water seeps into joints of rock, overnight temperature reaches below freezing, water freezes and expands by 10%, makes cracks bigger and puts strain on rock. this is repeated over many years and rock splits into sharp, jagged pieces called scree. these roll down mountainside and collect at the bottom in piles
• carbonation is an example of chemical weathering
• carbonation: rain falls, taking in carbon dioxide while passing through air. carbon dioxide mixes with water to form weak carbonic acid. limestone contains calcium carbonate, this reacts with weak carbonic acid rain and slowly dissolves. then washes it away in solution. best seen in karst landscapes (burren, county clare)