Features formed by glaciation

drumlin

is a stream-lined, longitudinal hill of moraine with tail pointing in the direction of ice advance.

Moraine

unsorted rock debris transported by ice and deposited by the melting of glaciers.

Esker

long snake-like formations consisting of sands and gravels left by glacial streams; serve as road building materials

Finger lake

a long, narrow lake in a glacial trough

The feature labelled X in the diagram above is a(n)

pyramidal peak

Pyramidal peak

forms as the three cirques in the picture erode the sides of the top of the mountain leaving behind the pinnacle of rock at the top

Cirque 

located along the side of the mountain where a glacier is eroding the landscape to eventually create a deep, steep-sided hollow

tarn

cirque filled with meltwater becoming a lake

arête

knife edged ridge between two cirques.

Medial moraine

two glaciers merge together into one main valley and their lateral moraines combine to form a strip of erosional debris down the middle of the newly formed combined glacier.

abrasion

erosion caused by rock particles embedded in the glacier wearing down the surfaces that they come in contact with

What feature contains sands and gravel that are useful for highway construction?

Esker

Loess

windblown silt from glacial outwash plains.

terminal moraines

moraine deposited at the front of glaciers.

Crag and tail

hard rock “crag” that resists erosion and a gently sloping “tail” of softer material deposited behind it by glacial movement

Truncated spur

smooth valley edge from when the glacier went through the former V shaped valley, truncating its interlocking spurs, to form a U shaped valley

Névé

compacted snow; transitional stage between snow and ice

plucking

rock loosened by freeze thaw action broken away as a glacier moves along it

striations

scratches made as ice with rocks on the bottom moves over rock surface

ribbon lakes

long parallel lakes formed on gouges left by glaciers and filled with meltwater

roch moutonnée

an outcrop of hard rock is smoothed on the side facing the ice and plucked by freeze thaw action on the side facing away

erratic

rock eroded and deposited somewhere amongst a different kind of rock

outwash plain

as an ice sheet melts, water pours from it carrying debris and depositing it at the edge of the ice forming thick layers of sand and rock beyond the terminal moraine

crevasses

cracks in the surfaces of glaciers produced by differential movement in the ice such as going around a corner in a valley or downhill which means a change of slope.

U-shaped valley

a wider, deeper and straighter formerly V-shaped valley

recessional morained

debris left by a glacier that maintained a constant position for a long time

interlobate moraine

debris left between the space of two glaciers which closely approached each other

spillway

valley formed by a river of meltwater carving into the landscape

misfit streams

occupy spillways; small in comparison to the size of the valley they are flowing in; the original river which formed the spillway would have been much bigger

What features are shared by both alpine and continental glaciers?

till, striations, terminal moraine, erratics, crevasses

Glacial ponding

body of water formed as a result of meltwater not being able to flow away.

lateral moraine

moraine / till at the sides of a glacier

ground moraine

moraine at the bottom of a glacier

fjord

long, narrow, deep sea inlet with steep sides, formed by the glacial erosion of a valley that was then flooded by the sea

Kame

a steep-sided mound of sand and gravel deposited by a melting glacier

Kame Terrace

a meltwater stream deposits its sediments between the ice mass and the valley wall

Kame terraces can also…

flatten out existing lateral moraine at the side of a valley

What lakes are formed from alpine glaciation?

ribbon, finger, tarn, proglacial

What lakes can not be formed by continental glaciation?

finger, tarn

What lake type does alpine glaciation NOT produce?

kettle lake

Where are ribbon lakes usually found?

glacial troughs (aka U-shaped valleys)

What is a rock basin

a hollow created by abrasion that will become a ribbon lake

rock bars

stronger, less eroded rock on either side of a rock basin. acts as dams where rainwater can accumulate to create a ribbon lake

What’s a canadian example of ribbon lakes? What type of glaciation is this?

Canadian shield in Ontario; continental glaciation

In Canada, where are finger lakes found

At the bottom of a valley

How is a kettle lake formed?

an isolated block of ice typically trapped underneath glacial meltwater melts, leaves a small depression and forms a lake in that depression.

How is a proglacial lake formed?

meltwater from a retreating glacier collects in a depression or behind a natural dam such as ice or moraines at the glacier’s front.

What is a pre-requisite for proglacial lakes?

something damming the meltwater like a glacier

What lake type is shown here?

Kettle lakes

What lake is shown in this image?

Tarn

What causes Lake Louise in Banff, Alberta to have a turquoise colour?

glacial flour suspended in glacial meltwater

Glacial flour

powder of silt and clay-sized rock particles created when glaciers grind against bedrock 

Glacial flour is rich in ________

nutrient

Aeolian transport

transported by wind

Fluvian transport

movement of materials by water in rivers and streams, involving erosion, transport, and deposition of sediment and solutes

What factors influence the shade of colour of a glacial lake containing glacial flour?

mineral composition, particle size, concentration and sunlight conditions. 

Nunatuks

first nations term for mountains peaking up above snow during ice age