Drumlins are elongated whale-shaped hills created by glacial
action. The name is derived from the Gaelic word druim meaning
“rounded hill” or “mound”. The long axis of the drumlin is parallel
to the movement of the glacial ice. This long gentle slope is known
as the Lee Slope. The blunter end, known as the Stoss end, faced
into the glacial movement. Drumlins may be more than 45m (150 ft)
high and more than 0.8 km (½ mile) long. Drumlins usually have
layers indicating that the material was repeatedly added to a core,
which may be rock or glacial till.
Approximately between c. 95,000 and c. 20,000 years before the
present day, the prairies were covered by a glacier, the Laurentide
ice sheet. The last major advance of the Laurentide ice sheet was
the Wisconsin Glacial Episode, which was between 70,000 and 30,000
years ago. It is likely that the Crown Hill Drumlin was created
during this time. There is some debate as to how exactly drumlins
are formed. According to Wikipedia: “There are many theories as
to the exact mode of origin and plenty of controversy among
geologists interested in geomorphology. Some consider them a direct
formation of the ice, while a theory proposed since the 1980s by
John Shaw and others postulates creation by a catastrophic flooding
release of highly pressurized water flowing underneath the glacial
ice. Either way, they are thought to be a waveform (similar to
ripples of sand at the bottom of a stream). It is also poorly
understood why drumlins form in some glaciated areas and not in
others. They are often associated with ribbed moraines.”
We aren't sure why this drumlin is named Crown Hill. We found it
called that on a local map. None of the locals we talked to seem to
know where the name came from. If anyone has information as to how
this drumlin came to be named please share it.
To log this earthcache:
1.Which direction does the Stoss side of the drumlin face?
2.Which direction was the glacier moving?
3.From the posted coordinates, take a photo of you or your GPS with
the drumlin in the background. Post the photo with your online
log.