Abstract
Astronomical forcing associated with Earth’s orbital and inclination parameters (Milankovitch forcing) exerts a major control on climate as recorded in the sedimentary rock record, but its influence in deep time is largely unknown. Banded iron formations, iron-rich marine sediments older than 1.8 billion years, offer unique insight into the early Earth’s environment. Their origin and distinctive layering have been explained by various mechanisms, including hydrothermal plume activity, the redox evolution of the oceans, microbial and diagenetic processes, sea-level fluctuations, and seasonal or tidal forcing. However, their potential link to past climate oscillations remains unexplored. Here we use cyclostratigraphic analysis combined with high-precision uranium–lead dating to investigate the potential influence of Milankovitch forcing on their deposition. Field exposures of the 2.48-billion-year-old Kuruman Banded Iron Formation reveal a well-defined hierarchical cycle pattern in the weathering profile that is laterally continuous over at least 250 km. The isotopic ages constrain the sedimentation rate at 10 m Myr−1 and link the observed cycles to known eccentricity oscillations with periods of 405 thousand and about 1.4 to 1.6 million years. We conclude that long-period, Milankovitch-forced climate cycles exerted a primary control on large-scale compositional variations in banded iron formations.
| Original language | English |
|---|---|
| Pages (from-to) | 369-374 |
| Number of pages | 6 |
| Journal | Nature Geoscience |
| Volume | 12 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - May 2019 |
Funding
We thank C. Albutt and Murphy for providing us with access to sections Woodstock and Daniëlskuil; S. Hilgen for help with the logging; H. Tsikos for arranging access to drill core Gasesa-1; N. Beukes for help with organizing the drilling and lutite sampling of drill core UUBH-1, which was drilled by OB Mining & Drilling Pty Ltd; and S. Meyers for advice on the spectral analysis. This study was supported by the Dutch National Science Foundation (grant NWO ALWOP.192), the Swiss National Science Foundation (grant 200021_169086) and the Dr. Schurmannfonds (grant 126-2017).
UN SDGs
This output contributes to the following UN Sustainable Development Goals (SDGs)
-
SDG 13 Climate Action
-
SDG 14 Life Below Water
Fingerprint
Dive into the research topics of 'Climate control on banded iron formations linked to orbital eccentricity'. Together they form a unique fingerprint.Cite this
- APA
- Author
- BIBTEX
- Harvard
- Standard
- RIS
- Vancouver