Communicate with archaeologists of the future

As part of its "Memory for future generations" program, Andra is studying how the Cigéo project could leave traces of its existence. Objective: to indicate to future generations the presence of a radioactive waste storage site. How to achieve it? "At Andra, several experiments are being conducted to identify and define a panel of appropriate means to preserve and transmit the site's memory," explains Frédéric Ego, a geological engineer at the Agency. Works of art, permanent papers and inking, semiotics (study of the signs), linguistics (study of the language) and now "archeology of the landscape" and durable media materials. It is in this context that Dominique Harmand, professor of geography and Vincent Ollive, lecturer and geomorphologist at the University of Lorraine, are currently testing the implementation of markers, in order to test this device for the future Cigéo.

The method, through an in situ experiment, aims at detecting and interpreting the trace of the human in the landscape. "Archeology and the study of the old sites of human occupation allow us to understand that after some time (hundreds of thousands of years), the disposal site - including its access ramps and shafts, backfilled after the closure of the site - will be masked by nature and future occupations, explains Vincent Ollive. It is therefore the landscape that will bear the memory of this construction. Our goal is to ensure that future cvilizations, with a technological level at least equivalent to ours, can correctly detect and interpret the nature of the site. "

For this, Vincent Ollive and Dominique Harmand Loterr laboratory of the University of Lorraine have reflected on the various traces that could reveal the presence of the site. "Commonly, archeology, sites are discovered through coins, tiles ... found in fields or forests, says Vincent Ollive. So we have deposited on the site artifacts of different shapes: cylinders, cubes, half-spheres ..., especially in shades of blue, pink, yellow ... that contrast with the shapes and colors of nature. In this way, the archaeologist of the future can deduce that there must have been a human presence on this site. "

For the design of these artifacts, ceramics (more precisely geopolymers) have the most advantages. It resists in the harshest environments, the vestiges of the History show that it is one of the materials which one finds most often and which sometimes retains traces of writing. A considerable advantage since the detection alone is not enough. It is then necessary to be able to correctly interpret the meaning of these objects and what they say about the life of the site. In two years, the researchers will return to the field to analyze how the artifacts will have moved with the erosion phenomenon. Finally, to analyze also how these will be detected and understood by individuals, a group of people, without prior information on this experiment, will be conducted in the field. We will then observe if it stops for questions in the presence of ceramics and if he questions their significance.