Learning From Negative Evidence
by Philip de Barros

Archaeological Research in the Oti River Valley

Kintampo sites are found in all major ecological zones; bone harpoons and fishhooks are found at some riverine sites, such as Ntereso along the Volta River (the Oti River is a major tributary of the Volta). I found a rasp (see drawing below) in the Bassar region of northern Togo. The Kintampo complex is characterized by the intensification of subsistence strategies (including oil palm and possibly yam and the appearance of domesticated goat or sheep), food processing, settlement, communication networks, exchange, personal ornamentation, and art (including shell ornaments and beads, polished stone armrings or bracelets and beads, polished stone axes of imported greenstone, and pottery with imported mica temper). Many scholars have argued for connections between the Kintampo cultural assemblage and earlier Saharan populations. It seemed therefore highly plausible that Kintampo sites were present along the Oti River, which would have served as a natural corridor for populations moving south from the ever-desiccating Saharan desert.

Stone rasp (1) and decorated potsherd (2) from Kintampo sites

The study area was a 60 km stretch of the Oti River between the district capitals of Mango and Mandouri. Several research strategies were used to select a zone where a set of systematic unaligned 500 x 500 m quadrats would be intensively surveyed. Data on current pottery types in the area was collected, including information on form, decoration, method of construction, temper types, and centers of production, data that would help interpret prehistoric ceramic patterns. Local geology was investigated for material useful for the production of stone tools (schist, flint, greenstone) and for possible iron ore deposits. Local farmers were interviewed for information about the location of oyster shell middens, smelting furnaces, slag mounds, and diagnostic artifacts associated with the Kintampo complex, especially the “rasps,” examples of which were shown to the farmers.

The results of the initial studies revealed a number of promising shell midden sites for test excavations to obtain charcoal for radiocarbon dating, including two stratified sites exposed in the Oti River bank and two others near riverine villages. They also helped choose a zone for the intensive survey to provide a representative sample of the variety of archaeological site types in the Oti River Valley. The intensive survey, led by Roland Sawatsky, focused on eight 500 x 500 m quadrats along the eastern side of the Oti River about 30 to 40 km northeast of Mango. The survey discovered twenty-five new archaeological sites, including a number of ceramic and aceramic Late Stone Age sites, a possible Middle Stone Age site, and numerous ceramic Iron Age village sites associated with semicircular rings of ancient baobab trees, oxbow lakes, and earthen mounds as well as areas with considerable smithing slag. A single smelting furnace site was also found. A study of ceramics in the field indicated a long tradition of using sherd temper and the presence of some imported types. However, local farmers did not recognize any of the Kintampo diagnostic artifacts and no trace of Kintampo sites were found. Apparently, those responsible for the Kintampo complex did not descend from the Sahara via the Oti River Valley in Togo.

The results of the study were disappointing in that no Kintampo sites were found, most of the freshwater oyster middens had been destroyed by colonial exploitation, and the middens that remain appear to be relatively recent. Nonetheless, the expedition answered an important question about the origins of the Kintampo culture. It did not, in fact, have links with the Oti River Valley in Togo and appears to be restricted largely to Ghana, although Kintampo sites may still be found in the rock shelters and hills of the Dapango region in the far north of Togo. The failure to find ancient oyster-shell middens suggests that this pattern of exploitation is relatively recent and associated with migrations of the Ngam Ngam into the valley only a few centuries ago. Archaeologists interested in the Late Stone Age and early Iron Age smithing sites will find considerable potential for future research there. The lithic material used at the Late Stone Age sites is a microcrystalline (flint-like) rock of relatively good quality that is easy to work and leaves easily identifiable wear patterns. The village sites associated with earthen mounds also merit special study.