Geophysical and Archaeological Survey in Igbo Oritaa (Iwo), Southwest Nigeria

  • Martins Olusola Olorunfemi
  • Benjamin Adisa Ogunfolakan
  • Ademakinwa George OniEmail author
Research Report


An integrated geophysical survey was carried out in Igbo Oritaa, a suburb of Iwo town (southwest Nigeria). The study was part of an archaeological investigation initiated by the Iwo community to identify and preserve the town’s ancient sites. The geophysical investigations involved ground magnetic profiling, 1D vertical electrical sounding (VES), and 2D electrical resistivity imaging. The magnetic survey revealed anomalies of dyke-like features (central magnetic low [negative] flanked by low amplitude positive shoulders), linear depressions with prominent negative amplitude magnetic lows, and a moderately high amplitude magnetic anomaly coinciding with an old trench and several anthropogenic mounds. The resistivity survey also indicates the presence of subsurface archaeological features, including ditches and walls. Excavation units were selected based on these geophysical attributes. The excavations uncovered dense deposits of potsherds, animal bones, shells, beads, iron slag fragments, a human premolar, metallic objects, a flute, and an architectural feature, possibly the foundation of a house. The geophysical survey and the test excavations confirm that Igbo Oritaa was an ancient settlement, consistent with the oral traditions. This paper presents the geophysical methods and results, the relationships between geophysical prospecting and test excavations, as well as the implications for community-focused archaeological research design, and site interpretation and preservation.


Igbo Oritaa Iwo (southwest Nigeria) Geophysical investigation Community archaeology 


Une étude géophysique intégrée a été réalisée à Igbo-Oritaa, une banlieue de la ville d’Iwo (sud-ouest du Nigéria). L’étude faisait partie d’une enquête archéologique initiée par la communauté pour identifier et préserver les sites ancestraux de la ville. Les études géophysiques ont porté sur l’établissement de profils magnétiques au sol, le sondage électrique vertical 1D et l’imagerie de résistivité électrique 2D. Les cartes magnétiques ont identifié des anomalies aux caractéristiques archéologiques présumées: des anomalies ressemblant à des dykes (basse magnétique centrale [négative]flanquée d’épaules positives de faible amplitude); dépressions linéaires avec des dépressions magnétiques d’amplitude négative importantes; et une anomalie magnétique d’amplitude modérée qui coïncidait avec une ancienne tranchée et plusieurs monticules anthropiques. Ces caractéristiques ont été corroborées par les cartes de résistivité en tant que zones de résistivité faible ou élevée. Les unités d’excavation ont été sélectionnées en fonction de ces attributs géophysiques. Les fouilles ont mis au jour des dépôts denses de tessons de poterie, d’os d’animaux, de coquillages, de perles, de scories de fer, d’une prémolaire humaine, d’objets métalliques, d’une flûte, et d’un élément architectural, éventuellement la fondation d’une maison. Les levés géophysiques et les fouilles expérimentales confirment qu’Igbo Oritaa était une ancienne colonie, conformant aux traditions orales. Cette articlea examiné les relations entre la prospection géophysique et les fouilles archéologiques, ainsi que les implications pour la conception de la recherche archéologique communautaire, ainsi que pour l’interprétation et la préservation des sites historiques.



The authors are grateful the paramount ruler, His Royal Majesty, Oba Abdulrasheed Adewale Akanbi, the Oluwo of Iwo who, through the Iwo Historical and Cultural Association (IHCA), invited us to carry out archaeological research in Igbo Oritaa. Messrs. T. K. Fadare and E. A. Adewale participated in the geophysical data acquisition. The authors are also grateful to the two anonymous reviewers whose comments have helped us improve the quality of the manuscript.

Funding Information

We thank the Iwo Historical and Cultural Association for financing the geophysical investigation, archaeological excavations, and site preservation effort.

Compliance with Ethical Standards

Conflict of Interest

The authors declare that they have no conflict of interest.


  1. Akinjogbin, I. A. (1992). The cradle of a race: Ife from the beginning to 1980. Port Harcourt: Sunray Publications.Google Scholar
  2. Arthur, J. W., Curtis, M. C., Arthur, K. J. W., Coltorti, M., Pieruccini, P., Lesur, J., Fuller, D., Lucas, L., Conyers, L., Stock, J., Stretton, S., & Tyko, R. H. (2019). The transition from hunting–gathering to food production in the Gamo Highlands of southern Ethiopia. African Archaeological Review, 36(1), 5–65.CrossRefGoogle Scholar
  3. Atkinson, R. J. C. (1952). Methodes electriques de prospection en archéologie. In A. Laming (Ed.), La découẹerte du passé (pp. 59–70). Paris: Picard.Google Scholar
  4. Ekinci, Y. L., Balkaya, C., Seren, A., Kaya, M. A., & Lightfoot, C. S. (2014). Geomagnetic and geoelectrical prospection for buried archaeological remains on the Upper City of Amorium: A Byzantine city in midwestern Turkey. Journal of Geophysical Engineering, 11(1), 1–17.Google Scholar
  5. Eluyemi, A. A., Olorunfemi, M. O., & Ogunfolakan, M. A. (2012). Integrated geophysical investigation of Orile-Oje archaeological site, Ogbomosho, Southwest Nigeria. The Pacific Journal of Science and Technology, 13(1), 615–630.Google Scholar
  6. Fleisher, J., & Sulas, F. (2015). Deciphering public spaces in urban contexts: Geophysical survey, multi-element soil analysis, and artifact distributions at the 15th–16th-century AD Swahili settlement of Songo Mnara, Tanzania. Journal of Archaeological Science, 55, 55–70.CrossRefGoogle Scholar
  7. Gaffney, C. (2008). Detecting trends in the prediction of the buried past: A review of geophysical techniques in archaeology. Archaeometry, 50(2), 313–336.CrossRefGoogle Scholar
  8. Gaffney, C., Hughes, G., & Gater, J. (2005). Geophysical surveys at King Lobengula’s palace KoBulawayo, Zimbabwe. Archaeological Prospection, 12, 31–49.CrossRefGoogle Scholar
  9. Geological Survey of Nigeria (1974). Iwo Sheet 60, 1:25,000 geological map.Google Scholar
  10. Iloeje, N. P. (1981). A new geography of Nigeria (New Revised Edition). Lagos: Longman Nig. Ltd.Google Scholar
  11. Ladipo, O., & Amoo, A. (2017). Iwoland and its untapped tourism potentials. Unpublished manuscript, 4pp.Google Scholar
  12. Leucci, G., & Greco, F. (2012). 3D ERT survey to reconstruct archaeological features in the subsoil of the “Spirito Santo” Church Ruins at the site of Occhiola (Sicily, Italy). Archaeology, 1(1), 1–6.Google Scholar
  13. Magnavita, C. (2016). Contributions of archaeological geophysics to field research in Sub-Saharan Africa: Past, present, future. Azania: Archaeological Research in Africa, 51(1), 115–141.CrossRefGoogle Scholar
  14. Magnavita, S. (2017). First geophysical exploration in the tumuli zone of central Senegal: A multidimensional approach. Azania: Archaeological Research in Africa, 52(1), 100–122.CrossRefGoogle Scholar
  15. Magnavita, C., Breunig, P., Ameje, J., & Posselt, M. (2006). Zilum: A mid-first millennium BC fortified settlement near Lake Chad. Journal of African Archaeology, 4, 153–169.CrossRefGoogle Scholar
  16. Novo, A., Vincent, M. L., & Levy, T. E. (2012). Geophysical surveys at Khirbat Faynan, an ancient mound site in southern Jordan. International Journal of Geophysics, 2012, 1–8. Scholar
  17. Ogundiran, A. (2002). Archaeology and history in Ilare District (Central Yorubaland, Nigeria), 1200-1900. Cambridge monograph in African archaeology no. 55. London: Archaeopress.Google Scholar
  18. Olorunfemi, M. O., Ogunfolakan, B. A., Chouin, G. L., Oni, A. G., Okunubi, M. O., & Akinwumiju, S. A. (2015). Integrated geophysical investigation of Yemoo Groove archaeological site in Ile-Ife, Osun State, southwest Nigeria. IFE Journal of Science, 17(3), 553–563.Google Scholar
  19. Oni, A. G. (2018). Integrated geophysical investigation of Ijoja archaeological site, Oke-Ako, southwestern Nigeria. Ph.D. thesis. Ile-Ife: Obafemi Awolowo University.Google Scholar
  20. Oyeyemi, K. D., Oladunjoye, M. A., Aizebeokhai, A. P., Ajekigbe, P. G., & Ogunfolakan, B. A. (2015). Integrated geophysical investigations for imaging archaeological structure in ancient town of Ile-Ife, Nigeria. Asian Journal of Information Technology, 4(7), 246–252.Google Scholar
  21. Pitt-Rivers, A. (1898). Excavations in Cranborne Chase, near Rushmore, on the borders of Dorset and Wilts (pp. 1880–1896). London: Harrison and Sons.Google Scholar
  22. Rahaman, M. A. (1989). Review of the basement geology of south-western Nigeria. In C. A. Kogbe (Ed.), Geology of Nigeria (2nd Revised ed., pp. 39–56). RockView: Jos.Google Scholar
  23. Vanic, M., & Rajovic, B. (2014). Geophysical survey at the archaeological remains of the Medieval Orthodox Church in Valjevo, western Serbia; student field camp case study. SEG Technical Program Expanded Abstracts, pp. 2114–2118. Society of Exploration Geophysicists Annual Meeting, Denver.
  24. Young, C. T., & Droege, D. R. (1986). Archaeological application of resistivity and magnetic methods at Fort Wilking State Park, Michigan. Geophysics, 51(3), 568–575.CrossRefGoogle Scholar

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Authors and Affiliations

  1. 1.Department of GeologyObafemi Awolowo UniversityIle-IfeNigeria
  2. 2.Natural History MuseumObafemi Awolowo UniversityIle-IfeNigeria

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