Eskers

Question 1

How are eskers formed?

Answer 1

Believed to be deposits made by subglacial streams. The channel of the stream will be restricted by ice walls, so there is considerable hydrostatic pressure which enables a large load to be carried and also allows the stream to flow uphill for short distances.
The bed of the channel builds up above the surrounding ground and a ridge is left when the glacier retreats during deglaciation.

Question 2

What is a beaded esker?

Answer 2

In some areas, the ridge of an esker is combined with mounds of material, possibly kames. This is a beaded esker.

Question 3

What features do eskers have?

Answer 3

Long ridges of material running in the direction of ice advance;
Sinuous form;
5-10m high;
Course sands and gravels;
Often stratified.