Chapter 1.2 Physical Environments - Upland Limestone Flashcards
A limestone pavement is formed in three steps:
- When glaciers passed over the top of an upland limestone area they removed the top soil leaving exposed rock.
- The rainwater then dissolved the limestone. The joints inbetween the rocks widened and deepend creating large blocks
- The cracks or fissues between the blocks are called grykes and the blocks called clints
Potholes/Swallow holes are formed when
widening of a major joint has occured, ususally when a stream dissapears underground.
Underground caverns occurs when
the process of dissolving limestone has continued underground.
Underground caverns are created when
sections of rock may have collapsed onto the bedrock creatinf underground caves.
Underground lakes and streams occur when
Surface water has met the impermeable underground rock.
Stalactites and stalagmites form in
underground caverns
What are the four steps to the formation of a stalactite?
- Through chemical weathering, particles of limestone are dissolved in solution by rainwater
- This water percolates through the rock and drops are deposited on the ceiling and floor of the cavern
- Gradually the moisture evaporates and the deposits of limestone are left.
- The deposits of limestone left hanging down from the ceiling of the caves are called stalactites.
What are the four steps to the formation of a stalagmite?
- Through chemical weathering, particles of limestone are dissolved in solution by rainwater.
- This water percolates through the rock and drops are deposited on the ceiling and floor of caverns
- Gradually the moisture evaporates and the deposits of limestone are left
- The deposits that build up from the ground are called stalagmites.
Intermittent drainage occurs when
streams that drain areas of impermeable rock carry on into a limestone area and disappear through the permeable limestone.
The stream flows along the bedding planes until it reaches the underlying permeable rock. Eventually as the stream flows along the water table, it emerges at the surface at a lower level. This water is called a spring.
This is an example of what feature?
Intermittent Drainage