Processes of glacial transport, erosion and deposition

Question 1

Moraine

Answer 1

any unsorted glacial debris ranging in size from large angular boulders to fine rock flour

Question 2

Supraglacial

Answer 2

transported on the ice surface in lateral or medial stripes

Question 3

englacial

Answer 3

transported within the ice if it falls down crevasses or is covered by subsequent snowfall

Question 4

subglacial

Answer 4

transported at the base of the ice and so particularly important as an agent of erosion

Question 5

abrasion

Answer 5

‘SAND PAPER EFFECT’ of sharp angular material embedded in the glaciers side/base. Needs a continuous supply of debris and produces smooth landforms scratched by parallel striations. indicate direction of ice flow

Question 6

plucking

Answer 6

caused by ice freezing around rocks protruding from valley or bed sides which are plucked away as glacier moves on. effective on well-jointed rocks

Question 7

attrition

Answer 7

caused by load being ground down to rock flour. rock flour carried in suspension gives glacial meltwater a milky appearance e.g. sour milk gill (easdale tarn

Question 8

pressure release

Answer 8

rock is replaced by ice that is of lower density. also occurs after weight of ice has been removed on melting

Question 9

unstratified-lodgement till

Answer 9

glacier base is plastered onto ground as too heavy (BOULDER CLAY) deposited in sheets

Question 10

unstratified-ablation till

Answer 10

combination of supraglacial, englacial and sub glacial moraine released by a stagnant glacier as it decays on melting. most water percolates down.