Glaciated Landscapes SG2a Flashcards
Define Geomorphic Processes
Natural mechanisms of weathering, mass movement, erosion, transportation and deposition which all influence the glaciated landscape system
Define Weathering
The in situ breakdown of rocks exposed at, or near, the land surface by physical, chemical or biological processes
Define Erosion
The wearing away or removal of rock and other material by a moving force
What are the five types of chemical weathering?
Oxidation, Solution, Hydration, Carbonation, Hydrolysis
What are the three types of physical weathering?
Freeze-thaw, Frost shattering, Pressure release
What are the two types of biological weathering?
Tree roots, Organic acids
Define Mass Movement
The downslope transportation of material under gravity
What are the three main types of mass movement?
Slump, Slide, Rock falls
Define Slides
Occur when an entire mass of material moves downwards along a straight line slip plane
Define Slumps
Occur where material slips down a curved slip plane with a rotational movement, leaving a series of back tilted steps or terraces
Define Rock Falls
Occur on a steep slope (over 70 degrees) where bare rock becomes detached from the slope by physical weathering and falls to the foot of the slope under gravity to form scree
What are the two types of erosion associated with glaciers?
Abrasion, Plucking
Define Nivation
A glacial process thought to include a combination of freeze-thaw, solifluction, transportation by water and possibly chemical weathering responsible for the initial enlargement of a hillside hollow
What are the three types of glacial debris during transportation?
Subglacial, Englacial, Supraglacial
Define Subglacial Debris
Transported at the base of the glacier, Mainly comes from plucking and abrasion
Define Englacial Debris
Carried within the glacier, Comes from surface debris which has fallen down a crevasse, sunken into the glacier or be buried by snowfall
Define Supraglacial Debris
Carried on the surface of the glacier, Comes from weathering and mass movement
Define Glacial Till
Material deposited directly by the ice
Define Glacio-Fluvial Material
Deposited by meltwater
What are the two types of drift?
Glacial till and Glacio-fluvial material
Define Lodgement Till
Material deposited at the base of advancing glaciers due to basal melting, The material is smeared onto the underlying rock due to the pressure of the ice as it continues to move
Define Ablation Till
Material deposited as the ice melts away from retreating/stagnant glaciers
What are the four distinctive characteristics of glacial till?
Angular, Unsorted, Unstratified, No orientation
Define Corrie
An arm-chair shaped hollow found on upland hills or mountain sides with a steep back wall, over deepened basin and a rock lip
