Diss Mere, Crater Lake or extinct Volcano?
The Domesday Book of the 11th century records the name Dice or Disce as the Saxon word for a pool of standing water – the modern spelling has descended from this. It is no exaggeration to say “The Mere is Diss ; Diss is the Mere”.
Diss Mere is an old lake in strange geological surroundings when you consider how it is meant to have been formed. Geology suggests it was formed by glacier retreat back in the last Ice Age. The problem with this theory is that the immediate landscape around it, that you can see with your own eyes, does not match this idea. One side of Diss Mere is very flat and there is a cricket pitch nearby. The other sides have either a steep but small hill or rolling hills. How were the hills, lake of flat land all created by the same process in such a short area?
How was Diss Mere formed/created?
The origin of the Mere has been a subject of considerable speculation. It was once considered to be bottomless, and to have been formed in the crater of any extinct volcano. Like crater lakes in others parts of the world it is certainly circular, but there the similarity ends. No records exist of volcanic action in East Anglia, nor are there any rock deposits to suggest it, in this most stable part of the country. Less than 30m below the surface at Diss is an extensive layer of chalk some hundreds of feet thick, it is likely that the Mere occupies a clay-filled depression in this chalk.
After surveys in 1980 it was said to be the second deepest natural lake in Britain.
To claim this cache you will need to visit two waypoint locations (as shown below) to enable you to message the answers to the following questions to the Cache Owner:
1. At the given co-ordinates you will find a large rock beside the path, describe this and explain how you think this got here.
2. Please state when the lake was formed and explain what caused it to be formed.
3. Estimate the volume of water in the Mere, ignoring the 23m of mud.
4. Upload an image of the lake with your log. It will be interesting to see how it changes from season to season. This is optional.