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Published June 18, 2024 | Version Published
Journal Article Open

BASE (Barberton Archean Surface Environments) – drilling Paleoarchean coastal strata of the Barberton Greenstone Belt

Creators

  • 1. ROR icon Friedrich Schiller University Jena
  • 2. ROR icon University of Johannesburg
  • 3. ROR icon University College London
  • 4. ROR icon California Institute of Technology
  • 5. Bât. B22 Early Life Traces & Evolution-Astrobiology, Quartier Vallée 1, Chemin de la Vallée 4, 4000 Liège, Belgium
  • 6. ROR icon Tohoku University
  • 7. ROR icon European Institute for Marine Studies
  • 8. ROR icon Utrecht University
  • 9. ROR icon University of the Witwatersrand
  • 10. The MSA Group, Henley House, Greenacres Office Park, Victory Road, Victoria Park, Randburg, Johannesburg 2195, South Africa
  • 11. Amethys Street, Mbombela 1200, South Africa
  • 12. ROR icon Texas A&M University
  • 13. Wildlife Estate, 367 Kierrieklapper Street, Hoedspruit 1380, Limpopo, South Africa
  • 14. Barberton Mines (Pty.) Ltd., Kaapmuiden Road, Barberton 1300, South Africa
  • 15. Barberton Community Tourism, Market Square, Barberton 1300, South Africa
  • 16. ROR icon Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences

Abstract

The BASE (Barberton Archean Surface Environments) scientific drilling project aimed at recovering an unweathered continuous core from the Paleoarchean Moodies Group (ca. 3.2 Ga), central Barberton Greenstone Belt (BGB), South Africa. These strata comprise some of the oldest well-preserved sedimentary strata on Earth, deposited within only a few million years in alluvial, fluvial, coastal-deltaic, tidal, and prodeltaic settings. They represent a very-high-resolution record of Paleoarchean surface conditions and processes. Moodies Group strata consist of polymict conglomerates, widespread quartzose, lithic and arkosic sandstones, siltstones, shales, and rare banded-iron formations (BIFs) and jaspilites, interbedded with tuffs and several thin lavas. This report describes objectives, drilling, and data sets; it supplements the operational report.

Eight inclined boreholes between 280 and 495 m length, drilled from November 2021 through July 2022, obtained a total of 2903 m of curated core of variable quality through steeply to subvertically dipping, in part overturned stratigraphic sections. All drilling objectives were reached. Boreholes encountered a variety of conglomerates, diverse and abundant, mostly tuffaceous sandstones, rhythmically laminated shale-siltstone and banded-iron formations, and several horizons of early-diagenetic silicified sulfate concretions. Oxidative weathering reached far deeper than expected. Fracturing was more intense, and BIFs and jaspilites were thicker than anticipated. Two ca. 1 km long mine adits and a water tunnel, traversing four thick stratigraphic sections within the upper Moodies Group in the central BGB, were also sampled. All boreholes were logged by downhole wireline geophysical instruments. The core was processed (oriented, slabbed, photographed, described, and archived) in a large, publicly accessible hall in downtown Barberton. A geological exhibition provided background explanations for visitors and related the drilling objectives to the recently established Barberton Makhonjwa Mountains World Heritage Site. A substantial education, outreach, and publicity program addressed the information needs of the local population and of local and regional stakeholders.

Copyright and License

© Author(s) 2024. This work is distributed under the Creative Commons Attribution 4.0 License.

Published by Copernicus Publications on behalf of the IODP and the ICDP.

Acknowledgement

We enthusiastically thank the ICDP Operations Support Group for continued help and advice through speedy advice, software and infrastructure over many years. The project would have been impossible to run without the legal, administrative, and financial guidance and activities of CIMERA (South Africa’s consortium for research drilling) and its staff, led by its former chair, the late Nic Beukes. We thank the University of Johannesburg for logistic support. The Council for Geoscience, South Africa, provided in-kind support by hyperspectral imaging. The goodwill and permits by the authorities of Barberton, Mbombela Municipality, Mpumalanga Province, the WHS administration, and the local development company BATOBIC are gratefully acknowledged. Landowners, including the Mountainland Trust, SAPPI, Barberton Mines, and the Vos Brothers are thanked for allowing access to and drilling on their private land. Many members of the Barberton community, including schools, businesses, and private citizens, provided excellent and timely services, volunteered their services, and were gracious and interested hosts. We thank the drilling contractor and its team for its dedication in the face of adversity. The BIAS Hall, owned by the Mpumalanga Province Department of Arts, Sports, and Culture and administered by the Barberton Regional Museum, was a perfect location to combine core processing with outreach activities. Staff of the Barberton Community Tourism office helped and advised in many day-to-day questions. Astrid Christianson provided professional community hospitality and made sure that all of us found in Barberton a “home from home”. A full list of the BASE staff is available in the operational report (Heubeck et al., 2024a).

Funding

This research was financially supported by the ICDP (03_2019 BASE), the NASA Exobiology program (grant no. 80NSSC21K0443 to Mike M. Tice), the Deutsche Forschungsgemeinschaft (He2418/25-1 to Christoph Heubeck), the National Research Foundation of South Africa to Nic Beukes, the Japan Society for the Promotion of Science (KAKENHI grant no. 20H00184 to Tsubasa Otake and co-PIs), the Fonds National de la Recherche Scientifique (FNRS) de la Fédération Wallonie-Bruxelles, Belgium (FNRS PDR T.0137.20 to Emmanuelle Javaux), the Dutch Research Council NOW (Open Competition Domain Science – XS to Paul Mason), by Desiree Roerdink through the University of Bergen, Norway (SPIRE 2020), funding from Roger Fu through the Harvard University Origins of Life Initiative, and from Johanna Marin-Carbonne through a Université de Lausanne starting grant. A detailed listing of funding sources and amounts can be found in the Operational Report (Heubeck et al., 2024a).

Data Availability

The DALL-E generative AI software, incorporated into Microsoft's Bing Internet browser (https://www.bing.com/images/create, Microsoft Inc, 2023a) or accessible through https://openai.com/index/dall-e-2/ (Microsoft Inc, 2023b), was used to generate the images of Fig. 1. This Scientific Report refers to Heubeck et al. (2024a, b, c). The data set is available at https://doi.org/10.5880/ICDP.5069.001 (Heubeck et al., 2024b).

Additional Information

This paper was edited by Nadine Hallmann and reviewed by Gary Byerly and Brian Pratt.

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Additional details

Related works

Is supplemented by
Dataset: 10.5880/ICDP.5069.001 (DOI)

Funding

National Aeronautics and Space Administration
80NSSC21K0443
Deutsche Forschungsgemeinschaft
He2418/25-1
National Research Foundation
Japan Society for the Promotion of Science
20H00184
Fund for Scientific Research
FNRS PDR T.0137.20
Dutch Research Council
University of Bergen
Harvard University
University of Lausanne

Dates

Accepted
2024-04-15

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Published