[will also be presented at GEO1 for 5mins]

In South Africa, air photographs were frequently used in the 1960s and 1970s to map the distribution of stone walled pre-colonial structures. The principal objective was to classify different ruin types, and to explain the diversity of types by associating each with a different historically known cultural or linguistic group, ultimately in order to reconstruct the peopling of this landscape. New and readily accessible technologies such as satellite imagery (especially through the software Google Earth) and Geographic Information Systems (GIS) justify revisiting the regional distributions of these stone-walled structures. These new tools can be usefully deployed to re-examine stone-walled settlements in the high plains (Highveld ) of South Africa to gain a more complete understanding of the pre-colonial sequence of change in social, political and economic organization.

To this end, a long term project is investigating the spatial archaeology of pre-colonial stone-walled structures (SWS) in an area of more than 7000 square km between Johannesburg and the Vaal River, in the southern part of Gauteng Province, South Africa. The survey area covers the entire basin of a major tributary of the Vaal River, the Klip, and two adjacent drainage basins. To facilitate the survey, these basins were subdivided in fifteen polygons, each bounded by major roads. Each polygon is being systematically surveyed on satellite imagery in Google Earth. In all survey polygons the initial step of tagging the site clusters has been accomplished by various research assistants at the School of Geography, Archaeology and Environmental Studies at Wits University. The subsequent steps of the survey include tagging each individual site, digitizing its outline for area calculation, classifying each SWS according to existing and modified typologies, and finally carrying out a range of spatial analyses using GIS software. In one of the polygons, Pam 1 in the center of the study area, the survey has progressed to the last stage. This poster describes the analysis and interpretation of the spatial patterns in the distribution of SWS in Pam 1. The results show significant changes in settlement patterns through time from dispersed homesteads to nucleated towns during the last two centuries before colonial times. These echo similar patterns reported in the neighboring North West Province, where they have been interpreted as a sequence of evolution in social, political and economic complexity.