Ancient Innovation in the Andes : Wetland Irrigation and Mining in the Bolivian Altiplano

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New research from the southern Bolivian Altiplano reveals how pre-Hispanic communities adapted to harsh climatic conditions in the 14th and 15th centuries CE. Sediment cores taken from the Saitoco wetland (3,650 m above sea level) show clear evidence of landscape transformation through irrigation and mining, despite a period of regional drought.

The findings highlight the construction of a network of channels that directed water from surrounding mountains into the wetland. This artificial irrigation led to increased plant growth, recorded in the sediments as a shift in organic matter composition and elevated levels of elements like selenium, bromine, and mercury. These geochemical changes are linked to biomass accumulation and point to intentional landscape management.

Advanced X-ray spectroscopy also revealed that bromine in the sediments was mostly preserved in organic forms, offering a new tool for reconstructing past environments. In parallel, rises in copper, lead, and antimony concentrations correspond to evidence of local mining and metallurgy, particularly during the Inca and Colonial periods.


The study combines environmental science and archaeology to document how ancient societies engineered their environment to support agriculture and resource extraction. It also opens new avenues for using chemical signatures in sediments to trace both climate and human history.

The full study is published in Quaternary Science Reviews (2024).

References :

  • Guédron et al., 2023, Proceedings of the National Academy of Sciences 120, e2215882120.
  • Leri & Ravel, 2015, Environ. Sci. Technol. 49, 13350-13359.
  • Thompson et al., 2013, Science 340, 945-950.

Authors and proposals :

Pre-hispanic wetland irrigation and metallurgy in the South Andean Altiplano (Intersalar Region, Bolivia, XIVth and XVth century CE), Stéphane Guédron (a,b), Clément Roy (a),, Géraldine Sarret (a),, Julie Tolu (c), Marie-Pierre Ledru (d), Sylvain Campillo (a),, Sarah Bureau (a),, Anne-Lise Develle (e),, Charline Guiguet-Covex (e), Eduardo Queiroz Alves (f), Mathieu Boudin (f), Richard Joffre (g), Pablo Cruz (h), Quaternary Science Reviews 338 (2024) 108826

  • (a) Univ. Grenoble Alpes, Univ. Savoie Mont Blanc, CNRS, IRD, Univ. G. Eiffel, ISTerre, 38000, Grenoble
  • (b) Universidad Mayor de San Andres, Instituto de Ecologia, LCA, La Paz (Bolivia)
  • (c) Eawag, 8600 Dübendorf, Switzerland and ETH Zürich, 8092, Zürich (Switzerland)
  • (d) ISEM (Institut des Sciences de l’évolution de Montpellier), IRD, Université de Montpellier, CNRS, EPHE, CIRAD (Centre de Coopération Internationale en Recherche Agronomique pour le Développement), INRAP (Institut National de Recherches Archéologiques Préventives), Montpellier
  • (e) Environnement, Dynamique et Territoires de Montagne (EDYTEM), Université Savoie Mont Blanc, CNRS, 73373, Le Bourget du Lac
  • (f) Royal Belgian Institute of Natural Sciences, Bruxelles, 1000 (Belgium)
  • (g) CEFE (Centre d’Ecologie Fonctionnelle et Evolutive), Univ. Montpellier, CNRS, EPHE, IRD, Montpellier
  • (h) National Scientific and Technical Research Council, UE CISOR CONICET UNJu, Jujuy (Argentina)