1. John Heinzelin observed that the surface of the water was higher
in the past, which is shown by the grey and blue levels of the diagram.
The orange and black levels were formed by water flow and human activity
and were never immersed underneath the water of the lake which was lowered
before the formation of these layers.
2. It is possible to see events which relate to the Katwe volcanoes: the black layer is volcanic ash spread by recent inhabitants. The orange layers consists of ash brought by the wind.
3. In prehistoric times, people lived there: archaeological remains which are at least 25 000 years old were discovered in the hatched levels!