extensively - produces landscapes that are unique to glaciation 1) Glacial Erosion 2) Glacial Transportation 3) Glacial Deposition 26 Page 27 WORK DONE BY GLACIERS 1) Glacial Erosion Plucking - breaking, lifting and removal of fragments of bedrock and sediments by ice (frost action) Abrasion - the scouring, smoothing or polishing action of materials embedded in the ice against the bedrock floor (sandpaper action)&#9;&#9; 27 Page 28 WORK DONE BY GLACIERS Controls on glacial erosion 1) the rate of glacial movement 2) the thickness of the ice 3) the shape, size, abundance, and hardness of the rock materials in the ice 4) the erodibility of the surface beneath the ice 25 Page 29 WORK DONE BY GLACIERS Erosional Features (Valley or Alpine Glaciers) 1) &quot;U&quot;-shaped glacial troughs as contrasted to &quot;V&quot;-shaped stream valleys (glaciers widens, deepens and straightens stream valleys) - type of valleys - main glacial trough and hanging valleys 29 Page 30 WORK DONE BY GLACIERS Erosional Features (Valley or Alpine Glaciers) 2) Truncated spur - irregular shaped cliff caused by removal of meanders 3) Cirque - a steep-sided, rounded bowl-shaped depression carved into a mountain wall at the head of a valley glacier 30 Page 31 WORK DONE BY GLACIERS Erosional Features (Valley or Alpine Glaciers) 4) Arete - a knife-edge peak formed by sideways erosion of two cirque glaciers 5) Horn - a pyramid-like peak at summits formed by headwards erosion of several coalescing cirques 6) Col - passage or gap formed by back-to-back erosion of cirques
(a steep-sided, rounded bowl-shaped depression; carved; into a mountain wall at the head of a valley) (Col - passage or gap; formed; by back-to-back erosion of cirques) (landscapes; are; unique to glaciation 1) (spur - irregular shaped cliff; caused; by removal of meanders 3) (the scouring; smoothing; ) (summits; formed; by headwards erosion of several coalescing cirques) (materials; embedded; in the ice against the bedrock floor)
a steep-sided, rounded bowl-shaped depression Col - passage or gap landscapes spur - irregular shaped cliff the scouring summits materials
carved formed are caused smoothing formed embedded
into a mountain wall at the head of a valley
by back-to-back erosion of cirques
unique to glaciation 1
by removal of meanders 3
by headwards erosion of several coalescing cirques
in the ice against the bedrock floor