Jean de Heinzelin was both a geologist and an archaeologist. At Ishango,
his goal was twofold: to collect geological data on the evolution of the lake
and archaeological data on the history of the people who lived there.
His team dug two large perpendicular cuts on the shore at the junction between
the lake and the Semliki river. By doing this, he could observe the stratigraphy
of the site, that is to say the different layers of sediment accumulated over time. The trench was cut with care to collect any archaeological objects, which were present by their thousands.
The site extends over a much larger area than the trench. There is a rich
scientific potential for future archaeologists. At the end of his excavations,
in 1959, Jean de Heinzelin took care to protect the stratigraphy. He
placed breeze blocks at the base of the trench and planted shrubs to
prevent erosion.la stratigraphie.