Test 6 Flashcards
Name two types of weathering and explain then
1.Mechanical weather is freeze thaw action it happens when the the temperature drops below freezing point and the water expands and puts pressure and the rocks and it breaks up into smaller pieces called scree
2.Chemical weathering is where rocks (limestone) are devolved because of a chemical reaction. Carbonation is an example of this. Carbonation + water = a weak Carbonic acid(Co2 + H20=H2Co3). Limestone has 80% calcium carbonate and when it mixes with the weak carbonic acid it dissolves the limestone
What is weathering
It is the breaking down of rocks that are exposed to weather
What is erosion
Erosion is the breaking down of rocks and soil and the transportation of the eroded material
What is hydraulic acid
Hydraulic acid is the force of moving water
Name and explain a surface feature
A swallow hole happens when Rivers flow over a limestone pavement and dissolves the rock. Carbonation and the physical force of moving water called hydraulic acid enlarges the joints and bedding planes. The place where the river disappears is called the swallow hole
Name and explain an underground feature
Caves and caverns: As rivers flow underground through swallow holes they enlarged the passages through which they flow. This occurs by the process of carbonation and hydraulic action. This process can widen the space underground creating these caves and caverns eg. The Aillwee Caves
What is calcite
It is the deposit of pure limestone
How do stalactites form?
As the water seeps in to the rocks it carries dissolved limestone with it some of this water reaches the roof of the cave and the drips slowly evaporate and leave behind small deposits of pure limestone called calcite
How do stalagmites form?
Drops of water may also seep through the rock and fall to the ground. This water evaporates and leave’s deposits of calcite on the floor of the cave directly below the stalactites. The calcite builds up forming up side down icicle shapes called stalagmites
How do pillars form?
After thousands of years stalagmites and stalactites can meet and join resulting in the formation of a pillar or column
How is regolith formed
Wearing and erosion produce loses material called regolith
What are factors that affect mass movement
Human activity
Weather
Water
Animals
Vegetation
Gradient(steepness)
What is a landslide
A landslide is the rapid movement of regolith down a steep slope that has become unstable. Causes of landslides include costal erosion deforestation heavy rain and earthquakes
What is an avalanche
An avalanche is the rapid movement of snow and ice downslope when the weight of the snow is too much for the slope too hold
How do mudflows happen
Mudflows happen when soil becomes saturated with water after periods of heavy rainfall and move down slope in a river of mud.
