The Long-Term Conservation of the Australopithecus-bearing Member 4 Excavation Walls at the Sterkfontein Caves, South Africa

Abstract

ABSTRACTThe Sterkfontein Caves UNESCO World Heritage site represents one of South Africa’s most valuable cultural heritage resources and is one of the world’s most prolific palaeoanthropological sites with its fossiliferous deposits spanning the last 3.5 million years. One of the most famous fossil-bearing deposits at Sterkfontein is the 2.5 million-year-old Member 4. This is the world’s richest Australopithecus-bearing deposit and has yielded iconic fossils like StS 5 – Mrs Ples, StW 53, two partial skeletons, and two species of Australopithecus. After 80 years of research, Member 4 continues to provide crucial evidence for human origins research. Over the last 35 years, since excavation of the Member 4 started exposing the walls of the deposit, their deterioration has been accelerating. The implications of this deterioration and impending collapse are severe, not only from a palaeoanthropological perspective but also a heritage management point of view. This article focuses on our efforts to conserve the deteriorating areas of the Member 4 excavation site. The project required the development of a comprehensive set of strategies that had to be adapted to the specific requirements of the national and local heritage management agencies and remain sensitive to ongoing research programmes. The strategy developed included: multiscale integrative documentation of the exposed deposits; comprehensive, independent but cohesive stabilization of the different components of the deposit while maintaining visibility for ongoing and future research; and installation of stabilization infrastructure that could be adapted to the long-term conservation excavation plan while maintaining deposit integrity and site safety.