Sangoan

Abstract

The Sangoan is a stone tool industry associated with the transition from the Early Stone Age (ESA) to the Middle Stone Age (MSA) in sub-Saharan Africa. The Sangoan overlies the Acheulean at sites including Nsongezi (Uganda) and Kalambo Falls (Zambia), and across much of Africa is the earliest technological marker for the shift from iconic Acheulean handaxes to the hafted points, blades, and smaller bifaces that characterize the MSA. Given its chronological position and status as an immediate post-Acheulean technology, the industry is pertinent to evolutionary questions about the origins of Homo sapiens in the late Middle Pleistocene. The Sangoan was named after the site of Sango Bay on the western shore of Lake Victoria in Uganda and was first described based on an assemblage of rugged tools dominated by thick, heavy-duty bifaces, choppers, and core scrapers. It was historically observed to cluster in and around the central African forest belt, but recent claims of Sangoan tools in North, West, and Southern Africa indicate that it may have a far wider distribution. These findings, along with the recovery of Sangoan artefacts in an open paleohabitat at Simbi (Kenya), have queried the long-standing association of the industry with woodland and rain forest ecosystems. Identifying and correlating Sangoan occurrences is made harder by the fact it has rarely been recovered from undisturbed archaeological contexts and it thus remains loosely defined and poorly dated. The few sites that have been dated are widely dispersed and broadly coalesce on a time frame of 250,000 to 300,000 years ago (ka BP), but these are likely to be significant underestimates. The paucity of well-stratified intact sequences that sample the Sangoan means that critical questions remain about its technological content, variability, and behavioral significance. The absence of any significant small tool component within many Sangoan assemblages has led to questions over whether this often bulky technology is suitable for hafting and whether, therefore, it may be better understood as a functional variant of the late Acheulean than as an MSA technocomplex. Recent use-wear analysis on Sangoan core axes at Sai Island (Sudan), however, has confirmed that many of the industry’s bifaces did serve as composite implements. At Kalambo Falls (Zambia), the presence of a small tool component, some with typical MSA characteristics, reinforces the Sangoan’s characterization as a mosaic technology that falls comfortably into neither the ESA nor the MSA.