Pingoruins in Broekhuizen
Broekhuizen is a hamlet near the scenic and fairy-like city of
Koekange. And not only is it an excelent shortcut for the
inhabitants of Koekange to reach the city Meppel and the highway
A28! It has a lot more to offer!
In Broekhuizen you can find a lace of Pingoruins! Four Pingo’s in
one line, very nice to see, and because of that we have made this
short walk for you! All four lakes are formed by winning peat from
the original bog they were about 150 years ago. This bog was formed
in so called pingo-ruines during many thousands of years.
This cache will teach you a little bit about a pingoruin, so read
the text below and go see all four pingoruins. The total distance
is approximately 4 kilometers.
In the second last ice-age, named the Saalien, Drenthe was covered
with an thick layer of ice. That ice came from Scandinavië. The
forests disappeared, and the wind blow over the empty landscape. At
that time Drenthe looked much like an artic landscape. The wind and
land-ice transported sand, clay and grit into the whole area. Mixed
together this three materials formed boulder clay that you can find
almost everywhere in Drenthe’s ground. The glacial ice also
transported big boulders to Drenthe, which where later used by
farmers to build there graves, better known as dolmens.
During the last ice-age, the Weichselien, the pingo’s where formed.
Pingo is Inuit for hill, A pingo is a small round hill with inside
of it a frozen lens shaped ice core, that can arise in areas where
the subsurface is permanently frozen (permafrost). Groundwater
underneath this frozen subsurface is standing under enormous
pressure and when a crack appears in the frozen subsurface, the
water is being pushed up. The water is unable to go trough the
frozen upper ground, thus freezes and expands. Underneath this ice,
the water remains under high pressure and keeps pushing the ice and
upper ground up; a pingo is born.
In the Netherlands there was a tundra climate during the
Weichsel-glacial, a period within the Pleistocene epoch about
116.000-11.500 years ago. In area’s where the groundwater was close
to the subsurface pingo’s could arise. At the end of the
Weichsel-glacial though, the temperature was slowly rising. At
first the top of the pingo would melt and some time later also the
ice core inside. The pingo collapses and sediment rolls from the
sides of the hill down to the ground. What remains is a depression
in the landscape surrounded by a small rampart of sediment; known
as a pingoruin. In the depression arises a lake that over a period
of thousands of years is being filled up with bog. The bog contains
valuable information about the vegetation, which can be used to
reconstruct the climate during the upholstering of the
Pingoruins are the best documented geological climate archives in
the Netherlands and precious study objects for quaternary
Park your car at: N52 41.397 E6 18.121
Park along the road so you don’t bother any persons living over
In order to complete this Earthcache you have to visit all four
Pingo ruins, do that by cycling or walking, don’t go by car!
To prove that you've visited al four Pingo's you have to answer the
Task for Pingo 1:
Standing at the coordinates, how many stables can you see when
Task for pingo 2:
How many Pollard Willows do you count next to the Pingo ruin, at
the right side of the house?
Task for pingo 3:
Take a photograph of one of your teammembers or yourselve while
holding your GPS. With the pingo in the background, upload that
photo with your log.
Task for Pingo 4:
At this point you have an excellent view at the Pingo, during the
summer it may be invisible because of the corn. When looking east
from this point you san see a big tree. What kind of tree is
Now that you've visted al four Pingo Ruins there is only one
What, if any, evidence can you see here that suggests these are
pingo's and not just lakes?
Add the picture with your log and mail us the answer from all