Sturts Trail – Pond 5
Pond 5 – spotting a kettle-hole
The depression ahead is a shallow kettle-hole (Ice Age pond). This is where an iceberg would have been grounded on the bed of the glacial lake. Depending on the time of year that you visit this could be a pond or the vegetation might be more green than the surrounding vegetation.
How to spot a kettle-hole
Kettle-holes can be very difficult to spot, especially in summer when they are dry. As you walk round this route you will see lots of these features. Hopefully by the time you walk back this way, you will be an expert at spotting the signs. The following gives the four characteristic identifying features of kettle-holes.
1 Glacial deposits
They only appear in areas which were covered by a glacier, from which the sediment was deposited as the ice melted. You cannot always tell this from looking at the landscape, but the geological map should identify areas of galcial deposits. This area is marked on the geology map as lake sediments surrounded by glacial deposits which gives us a clue as to how these depressions formed.
2 Clearly defined edge
Does the pond/depression have a clear outline? It does not have to be round but a kettle-hole should always have a clearly defined edge and should not sit on top of another similar depression.
3 No links to ditches or streams
Unless it has been altered by people, it should not have any links to ditches, streams or rivers and will not have any islands in the middle.
4 Similar depressions nearby
Are there lots of other similar depressions within the area? Kettle-holes tend to be created in clusters so it is very unusual to find one on its own.
If your pond/hollow meets these four criteria, it could be a kettle-hole. The next stage would be to see if there are peat deposits in the centre – these could contain material that can be used to date the age of the hollow. It is also possible to use geophysics to see the structure of the ground beneath to help confirm that this is how they formed. The photo shows an auger, which is used to bore down into deposits.