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Cluster analysis reveals increasing plume-like magmatism during progressive rifting in Afar (Ethiopia)
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  • Published: 31 January 2026

Cluster analysis reveals increasing plume-like magmatism during progressive rifting in Afar (Ethiopia)

  • Gianmaria Tortelli  ORCID: orcid.org/0000-0003-4845-34821,
  • Pierluigi Crescenzi2,
  • Carolina Pagli3,
  • Anna Gioncada3,
  • Derek Keir1,4 &
  • …
  • Linda Pagli5 

Scientific Reports , Article number:  (2026) Cite this article

We are providing an unedited version of this manuscript to give early access to its findings. Before final publication, the manuscript will undergo further editing. Please note there may be errors present which affect the content, and all legal disclaimers apply.

Subjects

  • Planetary science
  • Solid Earth sciences

Abstract

Reconstructing chemical variations of magma during rifting is challenging due to the heterogeneous mantle sources of the melt and different evolution pathways that magma potentially takes. Therefore, how and when the magma generation process evolves to that typical of an oceanic ridge (MORB-like composition) is still unclear. The Afar depression is an ideal place for studying magma changes during rift evolution, with North Afar close to breakup and older rift products preserved across the region. To investigate magma sources, we applied clustering analyses to a vast geochemical dataset of more than 1000 samples from the Afar rift. Combinations of different clustering methods (K-means and hierarchical) and assessment of correlation between features (Pearson coefficient) show that both trace element and isotope clustering group the North Afar samples, identifying a mantle source containing residual MREE-bearing minerals and an enriched mantle component. This suggests that North Afar, where the rift is closest to breakup, has a stronger influence of the Afar plume and more extensive partial melting of metasomatized lithosphere than the rest of Afar. We show that geochemical variations during rifting do not always follow a progressive transition toward a MORB-like composition but, instead, plume-like magmatism can increase until the most advanced stages of rifting (i.e., North Afar), potentially because the mantle plume is focused towards regions of thinnest lithosphere.

Data availability

The complete dataset used in this work and all cluster analysis results are presented in the paper and/or in the Supplementary material.

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Acknowledgements

We thanks Laurent Geoffroy for handling the manuscript, and the three anonymous reviewers for their constructive comments, which substantially improved the paper’s quality.

Funding

The research is part of the PhD of G. Tortelli, funded by the 2017 PRIN project-protocol MIUR: 2017P9AT72 PE10. G. Tortelli acknowledges support by the Tuscany Regional PhD Course in Earth Sciences. D.K. is partially supported through NERC grant UKRI1277. This study was carried out within the Space It Up project funded by the Italian Space Agency, ASI, and the Ministry of University and Research, MUR, under contract n. 2024-5-E.0 - CUP n. I53D24000060005.

Author information

Authors and Affiliations

  1. Department of Earth Science, University of Florence, Florence, Italy

    Gianmaria Tortelli & Derek Keir

  2. Gran Sasso Science Institute, L’Aquila, Italy

    Pierluigi Crescenzi

  3. Department of Earth Science, University of Pisa, Pisa, Italy

    Carolina Pagli & Anna Gioncada

  4. School of Ocean and Earth Science, University of Southampton, Southampton, UK

    Derek Keir

  5. Department of Computer Science, University of Pisa, Pisa, Italy

    Linda Pagli

Authors
  1. Gianmaria Tortelli
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  2. Pierluigi Crescenzi
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  3. Carolina Pagli
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  4. Anna Gioncada
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  5. Derek Keir
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  6. Linda Pagli
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Contributions

G.T. Conceptualization, Data curation, Formal analysis, Investigation, Visualization, Writing - original draft; P.C. Methodology, Software, Writing - review and editing; C.P. Conceptualization, Data curation, Funding acquisition, Supervision, Writing - review and editing; A.G. Investigation, Supervision, Writing - review and editing; D.K. Conceptualization, Funding acquisition, Supervision, Writing - review and editing; L.P. Methodology, Writing - review and editing.

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Correspondence to Gianmaria Tortelli.

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Tortelli, G., Crescenzi, P., Pagli, C. et al. Cluster analysis reveals increasing plume-like magmatism during progressive rifting in Afar (Ethiopia). Sci Rep (2026). https://doi.org/10.1038/s41598-026-35961-0

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  • Received: 25 September 2025

  • Accepted: 09 January 2026

  • Published: 31 January 2026

  • DOI: https://doi.org/10.1038/s41598-026-35961-0

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