G - Fluvioglacial processes Flashcards
What are they ways meltwater travels?
On the glaciers surface (supraglacial channels)
Within the ice (englacial channels)
Under the ice (subglaically)
Name the erosion processes by meltwater
Hydraulic action, corrasion, corrosion, attrition
What is hydraulic action?
Where the sheer force of the moving water is bale to dislodge loose particles of rock from the riverbed and banks eroding the stones, bed and banks of the river
What is corrasion?
Where stones in transport are thrown into the bed and the banks eroding them
What is corrosion?
Where weak acids within the water react with the rocks and bed and bank of the river
What is attrition?
Involved the bashing together of rock particles as they are carried downstream by the river - over time the constant collisions cause individual rocks to become similar and more rounded.
Name the ways rivers transport material
Solution, suspension, saltation, traction
What is solution? (transportation wise?)
Substances are dissolved in the water and carried along in solution in the water
What is suspension? (transportation wise?)
Fine light material is (whipped up by turbulance (erratic swirling of water) &) carried in the water
What is saltation?
Small pebbles and stones are bounced along the river bed (they are too heavy to be suspended)
What is traction?
Very large particles are pushed and rolled along the river bed by the force of the water
Name the differences between a fluvioglacial deposit and a glacial deposit?
F - Stratified (vertical layering due to seasonal variations)
G - No beds/layers
F - Sorted - larger rocks and boulders are deposited first as the melt water loses energy.
G - Unsorted (random sorting as ice melts and deposits material regardless of size)
F - Material is smooth and rounded (due to attrition), it is sorted and graded
G - Material is angular, from physical weathering and erosion (unaffected by water) and various shapes and sizes (boulders - rock flour)
