Preserving Tunisia’s Geological Heritage: A Collaborative Effort in Speleology and Karst Studies

The presence of abandoned mines represents an important historical heritage of Tunisia, which is yet only poorly recognised. Besides its patrimonial significance, detailed documentation of past mines is fundamental to 1) better understand the geometry of ore deposits; 2) assess natural hazards, e.g. associated with the collapse of voids; and 3) evaluate the impact of mineral deposits on groundwater quality.

We document this unique patrimony by integrating historical information with modern 3D topographic surveys using lightweight lidar technology at Djebel Serdj, where several old mines are documented next to Tunisia’s most extensive speleological networks. Our results support the spatial analysis of geomorphological features and contribute to a better understanding of lead-zinc ore deposits with respect to karst processes. Overall, the 3D visualisation of these complex networks supports scientific mediation efforts to protect a unique geological patrimony.

Collaboration with the Tunisian Geological Survey (ONM) started as early as 2012 to study the paleoenvironmental record in Tunisia. This research led to a trustworthy relationship, paving the way for fruitful scientific exchanges. Several field expeditions were organised to study the caves of Djebel Serdj. Besides its scientific contribution, ONM provided continuous logistical support to complete fieldwork in Tunisia’s most extensive cave networks. SISKA, on the other hand, supports with specialised expertise in karstology and palaeoclimatology. This transfer of knowledge is embodied by specialised workshops focusing on cave surveying techniques and the 3D modelling of karst systems. A Tunisian MSc student currently visiting SISKA is working specifically on the geomorphological analysis of the lidar data acquired in autumn 2022.

The leading house has offered general support to keep an existing and fruitful scientific partnership alive. As such, the grant acts as a strong incentive to tighten our network with Tunisian colleagues and envisage the submission of ambitious follow-up research proposals. The funding of this proposal provided access to state-of-the-art scientific instruments to our Tunisian partners. The November 2022 lidar survey of Grotte de la Mine represents a unique dataset which will be fundamental for the sustainable management of one of the largest cave networks in Tunisia.

Besides an immediate transfer of knowledge to ONM in the form of specialist training in advanced cave surveying techniques, this research grant also provides a unique opportunity for an MSc student from the University of Tunis to visit SISKA and get trained in 3D modelling techniques and quantitative geomorphological analysis. During her stay (July-August 2023), Marjem will, in particular, get familiar with karst processes to better assess the potential link with mineral deposits. Meanwhile, SISKA benefits from Tunisian mining expertise to interpret complex speleogenetic processes in Pb-Zn depositing environments.

As part of an international research initiative, I have been conducting fieldwork in Tunisia for more than a decade. Together with ONM, our local project partner, we have developed a strong collaborative framework to set up a preliminary collection of paleoclimate data at the highest scientific standards. For this endeavour, we have obtained full logistical support from ONM, without whom the research would not have been feasible. The project granted by the leading house permits us to pursue this collaboration to the benefit of our long-term goal which aims at a better understanding of the Tunisian karst record.

Besides the scientific results associated with such a project, the benefit on the human scale is immense. Although collaboration is not always straightforward when considering the contrasting scientific backgrounds, both parties benefit a lot by learning from each other. Setting up such a trustful partnership is not easy and requires many years. Ensuring funding for pursuing this research is thus fundamental to consolidating the efforts invested so far.