Weathering Flashcards
(22 cards)
Explain the term weathering
Weathering is the breakdown of rock soils and materials through the exposure to weather rain frost ice snow, wind and organisms
Three categories of weathering
Mechanical (physical)
Chemical
Biological
Types of mechanical weathering
Freeze thaw action (frost action)
Exfoliation (onion peeling)
Explain one type of mechanical weathering
Freeze thaw action
- Occurs in areas where temperature regularly changes between freezing and thawing. It occurs in areas of high altitude and high latitude. Freeze thaw action occurs in Ireland during the winter and for much of the years in mountain ranges.
During the day , water seeps into joints (cracks) in the rock.
By night, the temperature drops below freezing point (0°C) the water freezes and expands the water expands by up to 9% when frozen. This makes the crack bigger and put strain on the rock.
After repeated freezing and thawing of water , after many years, the rock splits.
Sharp, jagged pieces (screen) break off, they roll down the mountain side and collect pieces at the bottom of the slope.
Explain onion peeling
Exfoliation (onion peeling)
Occurs where rock layers peel off due to repeated heating and cooling causing expansion contraction and eventually cracking
It happens in areas where temperatures are extremely high during daytime and very low at night
Chemical weathering
Chemical weathering happens when rock is broken down by chemical reactions
Carbonation
Oxidation
Carbonation
Carbonation occurs in carbon dioxide (CO2) weather is rocks like a limestone and chalk
Rainwater mixes with CO2 to create carbonic acid , which dissolves calcium carbonate. Limestone can contain up to 95% of calcium carbonate.
The carbonic acid changes calcium carbonate into soluble calcium bicarbonate. This process is slower but more effective in cold water which holds more CO2.
Formula for carbonation
CO2 + HO2 = H2CO3 (carbon dioxide + water = carbonic acid
Biological weathering
Lichen - is an organism made of fungus and alga. It causes biological weathering, growing on rocks and producing chemicals that break down the rock surface
The Burren in Co. Claire -Coast landscape.
Coast land landscape is an area of exposed limestone formed by glaciation. Its features are formed by carbonation
Features of a karst landscape
Surface features
Limestone pavement
Clint’s
Grikes
Swallow hole
Sub surface features
Caves
Stalactites
Stalagmites
Pillar (columns)
One surface feature of a karst landscape
Limestone pavement - is created when glacier strip away soil, exposing limestone. Rainwater dissolves the rock, forming grooves called Grikes and flat slabs called Clint’s
Example the burning Co. Claire formed by carbonation
Explain how stalactites are formed 
Static tight 
Biological weathering
Mission is an organism made of fungus and another guy causes biological weathering growing on rocks and producing chemicals that breakdown (dissolve) the rock surface
What is a karst landscape?
A karst landscape is an area of exposed limestone, formed by glaciation. Its features are formed by carbonation
Surface features of a karst landscape
Limestone pavement
Clint’s
Grikes
Swallow holes
Sub surface features of a karst landscape
Caves
Stalactite
Stalagmite
Pillar
How was limestone pavement formed?
Limestone pavement is formed during glacier strip away soil, exposing limestone. Rainwater dissolve the rock, forming graves called Grikes and flat slabs called Clint’s.
Example -the Burren in Co. Clare
Explain how features of a cave are formed
Stalactite,stalagmite, pillar formation - when rainwater H2O mixes with carbon dioxide CO2 to phone carbonic acid H2C03. The carbonic acid reacts with the calcium carbonate in the limestone which contains up to 95% of calcium carbonate. The carbonate acid dissolves the calcium carbonate forming calcium bicarbonate which is soluble in water. The water then seep through limestone into a cave. The water evaporates on the cave ceiling and floor. Stalactite forms on a cave ceiling and a stalagmite forms on a cave floor. When stalactites and stalagmites meet a pillar/column is formed.
Advantages of tourism in the Burren
Social - outmigration for locals is reduced as spinoff jobs are created in arts, crafts and wellness industries
Economic - many direct and indirect jobs are created in hotels, cafés and eco-tourism. With 800,000+ visitors visiting the Burren in 2024
Environmental - strict planning laws within the Geo park prevent overdevelopment and protect the natural beauty in the area
Disadvantages of tourism
Economic - some jobs are seasonal running from April to September with most tourist visits
Social - house prices have increased as wealthy people by holiday homes
Environmental - traffic congestion from cars and buses and popular attractions (the cliffs of Moher) is a big issue with many CO2 emissions being released lowering air quality
Managing tourism in the Burren
Visitor management - limits are placed on visitor numbers in sensitive areas to prevent environmental damage 
