An elusive record exposed: radiocarbon chronology of late Holocene human settlement in the northern Congo Basin, southern Central African Republic

ABSTRACT

Archaeological surveys and excavations in the NGotto Forest Reserve, Central African Republic, discovered 98 artefact concentrations or cultural features that included ceramic scatters, iron-ore mines and iron smelting features. These investigations provide, for the first time, a series of radiocarbon dates that chronicle the timing and context of prehistoric occupation along the northern margin of the Congo Basin rain forest in the Central African Republic. Thirty-three age estimates from 19 sites are distributed throughout the late Holocene and together document 2500 years of occupations. A number of the dates are from iron extraction and processing features that reflect extensive pre-colonial use of the area between about AD 1750 and 1840, while a radiocarbon date of 2179 ± 37 BP in direct association with pottery signals settlement by ceramic-bearing peoples perhaps as early as 350 cal. BC. Three radiocarbon dates from two sites reflect occupations during the purported hiatus and reduction in regional forest populations c. 1400-800 BP and five dates from four additional sites in southern Central African Republic rain forests also fall during this interval. In concert with scrutiny of summed probability distributions and potential artefacts embedded within the radiocarbon calibration curve, the number of these dates question the reality of this occupational hiatus, at least in the north-central Congo Basin.

RESUMÉ

Des prospections et fouilles archéologiques effectuées dans la réserve forestière de NGotto, en République centrafricaine, ont permis de découvrir 98 concentrations d'artefacts ou restes d’activité, y compris des dispersions de céramiques, des sites d’extraction de minerai de fer et des fourneaux pour la fonte de ce métal. Ces études fournissent, pour la première fois, une série de datations radiocarbone qui retracent la chronologie et le contexte de l'occupation préhistorique le long de la bordure nord de la forêt tropicale du bassin du Congo en République centrafricaine. Trente-trois estimations d'âge provenant de 19 sites s’échelonnent tout au cours de l'Holocène tardif, et dans leur ensemble documentent 2500 années d'occupation. Un certain nombre de datations proviennent de contextes d'extraction et de traitement du fer qui reflètent une utilisation pré-coloniale intensive de la région entre 1750 et 1840 environ ap. J.-C. Par ailleurs, une datation au radiocarbone de 2179 ± 37 BP, directement associée à des céramiques, indique une occupation par des communautés utilisant la poterie, peut-être dès 350 cal. av. J.-C. Trois dates provenant de deux sites indiquent une occupation pendant c. 1400-800 BP, période qui avait été proposée comme un hiatus avec une réduction dans les populations de la forêt. Enfin, cinq dates provenant de quatre sites supplémentaires dans les forêts tropicales du sud de la République centrafricaine tombent également dans cet intervalle. De concert avec l'examen des distributions de probabilité sommées et des artefacts potentiels incorporés dans la courbe de calibration des datations radiocarbone, le nombre de ces dates remet en question la réalité de ce hiatus dans l’occupation, du moins pour ce qui est du nord-centre du bassin du Congo.

KEYWORDS:

• Central Africa
• chronology
• Iron Age
• pre-colonial
• radiocarbon
• rain forest

Acknowledgements

Thanks go to Guy Amaye, Mark Caudell, Alain Kolet Guy, Eduard Mboula, Kristin Safi and Timothee Tikouzou for logistical support and/or technical assistance. Comments from two anonymous reviewers helped us to clarify and expand portions of our discussions that were admittedly in need; any shortcomings, however, are our own. Special thanks to the foragers and farmers in Boua, Baboundji, Poutem, Bagbaya and Ndele who welcomed us into their villages with open arms and provided friendship and support.

Notes on contributors

Karen D. Lupo is a professor and current Chair at the Department of Anthropology at Southern Methodist University in Dallas, Texas. Utilising evolutionary theory, ethnographic records and ethnoarchaeological observations, her research examines human-animal interactions, vertebrate taphonomy and human ecology in both modern and prehistoric contexts.

Christopher A. Kiahtipes is a post-doctoral researcher with the Universität zu Köln's Institut für Ur- und Frühgeschichte - Forschungsstelle Afrika. He specialises in palynological analysis and Holocene human-environment dynamics in the Congo Basin and the Great Basin of western North America.

Dave N. Schmitt is an archaeological consultant and Research Associate with the Department of Anthropology at Southern Methodist University. His research includes late Quaternary archaeology and mammalian biogeography in the Great Basin of western North America and ethnoarchaeological studies among Central African farmers and foragers.

Jean-Paul Ndanga is an instructor and research archaeologist with the Centre Universitaire de Recherche et de Documentation en Histoire et Archeologie Centraficaines, Université de Bangui, Central African Republic. His research interests include lithic technology, prehistoric hunter-gatherers and Central African metallurgy.

D. Craig Young is a geoarchaeologist and Principal with the Far Western Anthropological Group in Carson City, Nevada. His research focuses on environmental influences and geomorphological processes affecting archaeological site formation and human interactions with changing late Quaternary landscapes.

Bernard Simiti is an African historian and has served as a professor and Director at the Centre Universitaire de Recherche et de Documentation en Histoire et Archeologie Centraficaines, Université de Bangui. He is currently a Director at the Ministère l'Enseignement Supérieur, de la Recherche, de la Science et de la Technologie in Bangui, Central African Republic.

Additional information

Funding

Research in the NGotto Forest was supported by funding from Washington State University and a grant from the National Science Foundation (No. 0924242). Excavations at the site of Limbumba were supported by the National Geographic Society (grant: 38136-06). This research was permitted by the Central African Republic Office of Scientific and Technological Research.