At the Teufelstisch near Bischofsmais, you´ll find two towers out of stone, built by nature. This process is called spherical weathering or woolsack weathering as the rounded rocks just look like sacks filled with wool.
But how did they get that form? Well, they were formed by several processes of weathering and erosion.
First, a massive rock, lying underneath the surface was split into cubes by physical means. Quite often, two of this means are water and frost = physical weathering.
In the next step, there´s an intrusion of rainwater enriched with oxygen, carbon dioxide and other aggressive substances. First of all, the cubes will be corroded at the corners and angles. The rounded shape is now formed ( = chemical weathering) - underneath the surface - that's important to know!.
In the next step, the soil erodes, especially by means of water and wind. What rests are the rounded rocks which stay layered one upon another as in the case of the Teufelstisch.
The following picture should give you an impression of these processes
And this are the questions to be answered, to log this cache:
Go to the aforementioned coordinates which mark the southern "tower".
1) what is the name of the native rock at the Teufelstisch
2) guess how high is the Teufelstisch
3) pls have a look at the contact area of the tower. What´s remarkable
regarding the contact area versus the rest of the tower?
4) take a picture of you and/or your GPSr at the rock and post it with your log
Please send your solution to question 1) to 3) at:
or to my account at geocaching.com
Please don´t write the answers into your internet-log at GC!