Developing a Geographic Information System (GIS) for mapping and analysing fossil deposits at Swartkrans, Gauteng Province, South Africa

The accumulation of fossil remains, bone tools, and stone tools at the Plio-Pleistocene site of Swartkrans has been attributed to a variety of depositional agents. These agents include hominin activity, carnivore activity, alluvial deposition, and gravitation. Based on recent studies, it is highly probable that the accumulations found at Swartkrans and other Plio-Pleistocene cave sites in South Africa have resulted from a combination of these processes. In order to explore further the taphonomic nature of Swartkrans, a Geographic Information System (GIS) was developed combining all existing information produced from the final seven-year period of C. K. Brain's excavations and a recent survey of the site. The amalgamation of this information into a GIS has resulted in a digital archive of Swartkrans information that allows the user to simultaneously visualize and analyse fossil, artifact, and geological materials within their original spatial contexts allowing a more comprehensive investigation of the site post-excavation. Three-dimensional reconstruction and GIS development for sites such as Swartkrans present many obstacles when using traditional GIS approaches. Due to the presence of overhanging features, certain limitations of conventional GIS software yield erroneous results. These limitations are based on the fact that conventional GIS packages interpret Z values as attributes rather than as true spatial coordinates. A brief overview of GIS and the challenges involved in the mapping and three-dimensional reconstruction of sites such as Swartkrans using traditional GIS approaches are discussed, as well as potential applications of the system. (C) 2002 Elsevier Science Ltd. All rights reserved.