Key Area 1.2 - Physical Landscapes Flashcards
How are limestone pavements formed
Glaciers passed over the top of upland limestone areas removing the top soil leaving an area of exposed rock, through abrasion
Water seeps through cracks in the limestone and the chemical weathering continues to widen the cracks forming grykes
The blocks left form blocks called clints and grykes
How are pot holes and swallow holes formed
Formed by the persistent weathering of a major joint such as a stream disappearing under ground.
Water seeps through joints and the stream will disappear and flow along underground channels
How are underground caverns formed
The process of dissolving the limestone continues underground and so sections of the rock can collapse creating underground caves
Where the surface water meets impermeable rock underground lakes and streams can be formed
How are stalagmites and stalactites formed
Water is loaded with dissolved limestone
When this drips from ceilings it deposits solid calcite which build down from the roof to form stalagtites
When the water splashes onto the floor it deposits solid calcite which build up from the ground to form stalagmites
If they meet they form a rock pillar
What is intermittent drainage
Occurs when streams carry onto a limestone area and disappear through the limestone. It then emerges at a lower level, this water is called a spring
What is limestone
Limestone is a sedimentary soft rock consisting of 80% calcium carbonate formed millions of years ago
What is a Tributary
A river which joins to a larger river
What is a Catchment
The area from which water drains into a particular drainage basin
What is a Confluence
The point at which 2 rivers join
What is a Watershed
The boundary dividing one drainage basin from another
What is a Mouth
Where the river flows into a sea or other large body of water
Name some of the features of a river in the upper course
V shaped Valleys
Waterfalls
Plunge Pools
Name some of the features of a river in the middle course
Meanders
Interlocking Spurs
Name some of the features of a river in the lower course
Oxbow lakes
Levees
Flood plains
Deltas
What are the processes of erosion
Hydraulic action
Corrasion
Corrosion
Attrition
What is hydraulic action
A process of erosion
Breaking away of the river bed and banks by the sheer force of the water getting into small cracks
What is Corrasion
Process of erosion
The wearing away if the river bed and banks by the weight of the load hitting against them
What is corrosion
Process of erosion
When the water dissolves mind earls from the rocks and washes them away
What is attrition
Process of erosion
The wearing away if the load as rocks and pebbles hit each other and the river bed breaking into smaller and more rounded pieces
