Weathering Flashcards
Denudation
The Earth’s surface being worn down by weathering + erosion
Weathering
The process that physically breaks down rocks into sediment
Erosion
The process that breaks down + moves the sediment
Mechanical weathering
The physical breaking down of rock
Chemical weathering
when the rock decays/dissolves
Freeze-thaw action
Water collects in the cracks in the rock
At night the water freezes + expands
Repeated freeze-thaw action makes the rock shatter + fall to the bottom of the slope as scree
Carbonation
Carbon dioxide mixes with rainwater to form a weak carbonic acid
Limestone contains calcium carbonate. When the carbonic acid in the rainwater falls into the limestone, a chemical reaction takes place.
The calcium carbonate in the limestone starts to dissolve. This is carbonation
Limestone is a permeable rock, so water can easily pass through
Vertical cracks in limestone are known as…
Joints
Horizontal cracks in limestone are known as…
Bedding planes
Karst landscapes
Landscapes made of exposed limestone
Karst landscape - clints
Slabs of rock on the surface that separate the grikes
Karst landscape - grikes
Deep grooves in the pavement. They are weathered, widened + deepened by carbonation
Limestone cave
Seeping rainwater + rivers flow underground + dissolve the limestone due to carbonation
Gradually, large open areas called passages + caves are formed
When the water with carbonic acid seeps into the cave roof, it starts dripping + some droplets hang from the roof. As they hang, water evaporates + leaves a deposit of calcite. These deposits build up + form stalactites
If droplets fall to the floor, they leave calcite deposits, that build up + form stalagmites
If a stalactite + stalagmite join, they form a pillar
