CaltechAUTHORS
Published March 2025 | Published
Journal Article Open

Sill Stacking in Subseafloor Unconsolidated Sediments and Control on Sustained Hydrothermal Systems: Evidence From IODP Drilling in the Guaymas Basin, Gulf of California

Galerne, Christophe1 ORCID icon
Cheviet, Alban1, 2 ORCID icon
Kahl, Wolf‐Achim1 ORCID icon
Wiggers, Christin1 ORCID icon
Bach, Wolfgang1
Neumann, Florian3
Buatier, Martine2
Höfig, Tobias W.4, 5
Lizarralde, Daniel6 ORCID icon
Teske, Andreas7 ORCID icon
Peña‐Salinas, Manet8 ORCID icon
Karstens, Jens9 ORCID icon
Böttner, Christoph10 ORCID icon
Berndt, Christian9 ORCID icon
Aiello, Ivano W.11 ORCID icon
Marsaglia, Kathleen M.12
Gontharet, Swanne13
Kuhnert, Henning1 ORCID icon
Stock, Joann M.14 ORCID icon
Negrete‐Aranda, Raquel15 ORCID icon
Zhang, Junli1 ORCID icon
Kopf, Achim1
  • 1. ROR icon University of Bremen
  • 2. Laboratoire Chrono‐Environment, UMR 6249, Université Franche‐Comté, Besançon, France
  • 3. ROR icon Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences
  • 4. ROR icon Texas A&M University
  • 5. ROR icon Forschungszentrum Jülich
  • 6. ROR icon Woods Hole Oceanographic Institution
  • 7. ROR icon University of North Carolina System
  • 8. ROR icon Autonomous University of Baja California
  • 9. ROR icon GEOMAR Helmholtz Centre for Ocean Research Kiel
  • 10. ROR icon Aarhus University
  • 11. ROR icon San Jose State University
  • 12. ROR icon California State University, Northridge
  • 13. ROR icon Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques
  • 14. ROR icon California Institute of Technology
  • 15. ROR icon Center for Scientific Research and Higher Education at Ensenada

Abstract

Magma emplacement in the top unconsolidated sediments of rift basins is poorly understood. We compare two shallow sills from the Guaymas Basin (Gulf of California) using core data and analyses from IODP Expedition 385, and high-resolution 2D seismic data. We show that magma stalling in the top uncemented sediment layer is controlled by the transition from siliceous claystone to uncemented silica-rich sediment, favoring flat sill formation. Space is created through a combination of viscous indentation, magma-sediment mingling and fluidization processes. We show that sills emplace above the opal-A/CT diagenetic barrier. Our model suggests that in low magma input regions sills emplace at constant depth from the seafloor, while high magma input leads to upward stacking of sills, culminating in a funnel-shaped intrusions. Our petrophysical, petrographic, and textural analyses show that magma-sediment mingling creates significant porosity (up to 20%) through thermal cracking of the assimilated sediment. Stable isotope data suggest carbonate formation at 70–90°C, consistent with background geothermal gradient at 250–325 m depth. The unconsolidated, water-rich host sediments produce little thermogenic gas through contact metamorphism, but deep diagenetically formed gas bypasses the low-permeability top sediments via hydrothermal fluids flowing through the magma plumbing system. This hydrothermal system provides a steady supply of hydrocarbons at temperatures amendable for microbial life, serving as an incubator that may be abundant in magma-rich young rift basins and play a key role in sustaining subseafloor ecosystems.

Copyright and License

© 2025. The Author(s).

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Acknowledgement

This research used samples and data provided by the International Ocean Discovery Program (IODP). Funding for this research was provided by the Deutsche Forschungsgemeinschaft (DFG, German Research Fundation) funding priority program SPP 527. Project number 447431016 (#GA 1939/6-1 and #GA 1939/6-2) is led by Christophe Galerne at the University of Bremen. The Bundesanstalt für Geowissenschaften und Rohstoffe (BGR) and European Consortium for Ocean Research Drilling (ECORD) provided funds for sailing. Shipboard data presented here is accessible online (https://web.iodp.tamu.edu/LORE/). We sincerely thank the IODP technical staff and the R/V JOIDES Resolution crew for their invaluable assistance. We thank members of the science party of IODP X385 that are not directly involved with this research for their invaluable shipboard contributions. We also thank the entire staff of the R/V JOIDES Resolution for their flawless technical support, and our outstanding outreach officer and science journalist Rodrigo Pérez Ortega. The authors thank the two reviewers, Joe Cartwright and an anonymous reviewer, for their constructive comments. We also thank the editor, Douglas Schmitt, for his additional comments and advice. Open Access funding enabled and organized by Projekt DEAL.

Contributions

Conceptualization: Christophe Galerne.
Data curation: Christophe Galerne, Wolf‐Achim Kahl, Christian Berndt.
Formal analysis: Christophe Galerne, Alban Cheviet, Wolf‐Achim Kahl, Christin Wiggers, Florian Neumann, Henning Kuhnert, Junli Zhang.
Funding acquisition: Christophe Galerne.
Investigation: Christophe Galerne, Alban Cheviet, Wolf‐Achim Kahl, Christin Wiggers, Wolfgang Bach, Florian Neumann.
Methodology: Christophe Galerne, Wolf‐ Achim Kahl.

Project administration: Christophe Galerne.
Resources: Christophe Galerne.
Supervision: Christophe Galerne, Wolfgang Bach, Martine Buatier, Junli Zhang, Achim Kopf.
Validation: Christophe Galerne.
Visualization: Christophe Galerne, Alban Cheviet, Jens Karstens, Christoph Böttner.
Writing – original draft: Christophe Galerne.
Writing – review & editing: Christophe Galerne, Alban Cheviet, Wolf‐Achim Kahl, Wolfgang Bach,
Florian Neumann, Martine Buatier, Tobias W. Höfig, Daniel Lizarralde, Andreas Teske, Christian Berndt, Kathleen M. Marsaglia, Henning Kuhnert, Joann Stock.

Data Availability

Supporting Information S1, includes eight text sections, that are supplied with a total of 13 Figures, four Tables, and three equations. The IODP X385 data presented in SI-1 are available from https://web.iodp.tamu.edu/LORE/ and are described in Teske et al. (2021a). SO241 seismic data presented in SI-2 are available from PANGAEA (Berndt et al., 2022): https://doi.pangaea.de/10.1594/PANGAEA.944765. Alpha Helix AH1605 seismic data are published in the IODP Proceeding volume of the X385 and available at IODP Site Survey Data Bank (https://ssdb.iodp.org/SSDBquery/SSDBquery.php; select P833 for proposal number, Site Names: GUAYM-01B, GUAYM-02B, GUAYM-03B, and GUAYM-12A, see Teske et al., 2018 and reference therein). The bathymetry map of the Ringvent system (Sites U1547 and U1548) is from AUV Sentry dive 410 (Teske et al., 2019). Thermal state data presented in SI-5 are reported in the X385 Proceeding volume https://doi.org/10.14379/iodp.proc.385.2021, and are accessible at the open access repository database of IODP: https://web.iodp.tamu.edu/LORE/. Other data presented (i.e., SI-4 and SI-8 in Supporting Information S1) are directly generated out of the present study and reported in form of quantitative table. Micro-Texture Imaging data presented in the main text and in Supporting Information SI-7 are available from PANGAEA (Kahl & Galerne, 2025a, 2025b, see Table 3).

Supplemental Material

Supporting Information S1

Supporting Information S2

Supporting Information S3

Supporting Information S4

Supporting Information S5

Supporting Information S6

Supporting Information S7

Table S1

Files

JGR Solid Earth - 2025 - Galerne - Sill Stacking in Subseafloor Unconsolidated Sediments and Control on Sustained.pdf

Additional details

Related works Funding Dates Caltech Custom Metadata
Created:
March 25, 2025
Modified:
March 25, 2025