Smooth, oval shaped hills
found in lowland locations on
valley floors where the ice has
emerged from the highlands
Can be as long as 1.5km (most
smaller) and up to 60m in height
Poorly sorted glacial till
Steep end (stoss) and gently sloping end (leeside)
Elongated in direction of ice advance
Often found in-groups known as
swarms 'basket of eggs
topography'
Eden Valley, Cumbria
Debate over exact formation of drumlins as formed sub glacially and only revealed once ice has disappeared
Lodgement of subglacial debris as melts out of basal ice
Reshaping of previously deposited material during subsequent re-advance
Accumulation of material around a bedrock obstruction (rock-cored drumlins)
Thinning of ice as spreads over lowland area reducing ability to carry
debris, continued forward movement streamlines feature
Erratics
Individual pieces of rock with
distinctive geology different
from the area in which they
were found
May vary in size from
small pebbles to large
boulders
Norber Erratics - Yorkshire Dales
Pieces of rock which have been
transported by a glacier from one
area and deposited in an area of
different rock type
Likely they were eroded by plucking and
entrained in the glacier or were
frost-shattered from the valley sides,
becoming supra-glacial debris by rockfall