The Dynamics of Mounds-Clusters in the Mouhoun Bend (Burkina Faso)

Mounds are human made accumulations of settlements debris of varying size and shapes, found in different parts of the world.
In West Africa, they tend to be located in relatively flat lands, at low elevations, in wetlands, marshlands or flood plains..


-4302
KST-3 (20-  Archaeological Project [21,22]. The Mouhoun River flows from the SW to NE, winds its course in a U-shape bend to follow a N-S direction ( Figure 1). The study area located in the Sudano-sahelian zone is delimited in the north and northeast by the meandering river course. It measures 40km

The Study Area
Seventeen settlements with two to seventeen mounds (Tomo in local Marka language) each were recorded in an area measuring 20km east-west and 25km north-south ( Figure 1). Kirikongo and Tora-Sira-Tomo/Gnambakouon-Sira-Tomo (TST/GST) are located at 280 to 284m above sea level (asl). All the remaining settlements are found at elevation ranging from 280 to 260m asl. There is an intriguing concentration of mound-clusters around Douroula in the central part of the surveyed area. The density of settlement is surprisingly low in the river valley if one considers that the region is prone to cyclical droughts. River blindness has plagued the whole Mouhoun River basin during the colonial period, and probably before. This may explain the avoidance of the river shores for direct settlement. There is no single permanent village on the river banks today. Instead, there are seasonal fishing camps set by non-local fishermen.

The Dynamics of TST and KST Mound-clusters
The long-term pattern of growth of inhabited space within a mound cannot be assessed with the field methodology implemented is located at 280m asl. With 17 distinct mounds, it is the largest settlement complex of the study area, spread over 900m westeast and 500m north-south, some 45ha in total surface extent ( Figure 2). TST-3, the largest mound stretched along the north edge measures 260m west-east, and 120m north-south. All 17 mounds were tested after three field seasons (1997, 1999, and 2000). Five, TST-1 (Iron smelting), TST-2 (quarry), TST-4 (cloth weaving and dyeing workshop), TST-9 (cemetery), and TST-17 (oil production workshop), are special purpose sites. The fourteen remaining ones were standard habitation mounds with varying occupation intensity.   At TST, the initial settlement phase (650 BC-800 AD) that started in the mid-1 st millennium BC is documented at TST-1, TST-2, and TST-3-East ( Figure 4, Table 2). The earliest occupations are found at TST-1, an iron-smelting site dated to 650-395 BC ( Figure 5), TST-2, the quarry site that provided raw material for house construction and iron production, and finally, the blacksmith workshop exposed at the bottom of TST-3-East probe.

Peer-village interaction
The study area is relatively flat. The recorded settlement complexes are more or less evenly distributed in the landscape.
In site-catchment analysis terms, each village is surrounded by rings of cultivated fields, fallow zones, and bush [23,24]. At their peak, during the first centuries of the 2 nd millennium AD, each of the recorded settlement complex was a large autonomous and selfsustaining village. Some, like KST and Kirikongo, were compact villages with a few outlying mounds and special purpose sites.
Others, as was the case for TST -GST and Diekono, were spread out with a multiplicity of distinct mounds.
There are no significant wealth differences. Grave-goods and burial offerings are too marginal to be significant. Some individuals, male, female, children, and infants, were nonetheless buried in "restricted access" cemeteries while others were buried in their compounds. This differential treatment points to subtle variations in social status without detectable and/or durable material correlates. The accelerated growth at the beginning of the 2 nd millennium AD initiated a scramble for land, villages rivalry, violence, and wars.

Fire: accidents or wars?
Burnt houses were recorded in some of the excavated mounds.
It is the case at TST-3-West in occupation I and II, dated to 1000-1150 AD. Domestic installations belonging to two successive occupations were totally burnt down. KST complex also present two instances of burnt domestic installations dated to 1050 -1380 AD: one at KST-3 occupation I and the other at KST-4 occupation II.
In the latter case, a whole household complex with its food supply was destroyed by fire ( Figure 9). Similar cases of burnt installations dated to 1300-1450 AD were recorded at Kirikongo, Mound III, level 8 and Mound IV, level 7 [8]. These events took place during a period of accelerated growth that triggered violent confrontations.

War, Violence and surgery
There is no direct one to one correlation but the unrest indicated by burnt houses is partly corroborated by traumatic injuries found  [25][26][27].
The surgery may have taken place after a violent raid. Finally, a 9-11 years old pre-adolescent, individual 18 from phase IV TST-9 cemetery, presents multiple peri-mortem depressed cranial features made by a sharp object, that was very likely the cause of death [26].
The recorded evidence on traumatic injuries is dated to phase III (1000-1200 AD) and IV (1250-1500 AD) when the area witnessed a significant growth acceleration followed by the onset of devolution. There are convincing evidence of conflict and intervillage warfare during the first half of the second millennium AD.
The nature and characteristics of the kind of warfare that may have developed in the area during this phase of accelerated growth are difficult to decipher. The tactics involved may have consisted of surprise raiding and counter-raiding with the aim of seizing supplies and host [27][28][29][30][31][32][33][34][35][36][37].

Conclusion
Each village had its autonomous system of government, with horizontally differentiated groups. These mixed farming communities included a number of craft specialists, potters, ironsmelters and blacksmiths, masons, cloths weavers and dyers, karite-oil producers, as well as part-time warriors, and healers (surgeons). The Mouhoun Bend peer-villages were autonomous and self-sustaining but not autarkic. A general compatibility of "worldviews" is suggested by the strong coherence of mortuary practices. Despite variations, pottery decoration techniques and syntax suggest a shared cultural universe. The mound-dwellers of the Mouhoun Bend developed an original socio-political system that, for approximately two centuries, from 1200 to 1400 AD, existed on the periphery of the powerful expansionist Mali Empire.

Acknowledgments
The Students from the University of Paris X Nanterre, the University of Ouagadougou, and the University of California, San Diego participated with enthusiasm to the field programs.