submergent features
- Created by: Libby Easden
- Created on: 25-02-13 19:27
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- Submergent features
- Rias: rising sea-levels drown river valleys, middle and upper course of valley= filled with water> high land =dry
- Cornwall: sea level rose drowning valleys of the rivers flowing off Dartmoor and uplands of Cornwall.
- Devon: knights bridge estury in south Devon
- long section ans cross profile of typical river valley, and usually the dendritic system of drainage
- Fjords: drowned glacial valleys: coasts of Norway, New Zealand, Canada, Chile and Greenland.
- western Scotland: has some but they are not well developed as ice was not as thick or did not last as long.
- Steep valley sides, straight and narrow, U shaped cross section and hanging valleys on either side
- unlike Rias the are not deepest at mouth but consist of a glacial rock basin - shallow section at the end = threshold
- threshold= reduces glacial erosion as the glacila comes in contact with sea, thinning the ice
- formed when sea drown lower part of glacial valley
- Rias: rising sea-levels drown river valleys, middle and upper course of valley= filled with water> high land =dry
- Emergent features
- Raised beaches: area of former wave-cut platforms + beach above present sea-level.
- behind beach may find old cliff line with wave-cut notches, sea caves, arches ans stacks
- common on coast of western Scotland
- 3 levels has been recognized 8m, 15m and 30m
- West of the Isle of Arran = well developed raised beach
- relict cliff, arches, stacks and caves
- around 4-5 m above sea-level
- suggests sea has fallen to current level
- however sea level has risen since last iceage
- beach has reaches its raised position by isostatic rising of the land
- Raised beaches: area of former wave-cut platforms + beach above present sea-level.
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