AI Insight
This study uses zinc isotope analysis of carbonatites (carbonate-rich igneous rocks) from both Phanerozoic and Precambrian periods to investigate when deep carbon cycling began on Earth. The researchers present isotopic evidence suggesting that the process of subducting carbon into Earth's mantle and recycling it back to the surface was already operational during the Archean eon, over 2.5 billion years ago. This finding pushes back the timeline for when Earth's deep carbon cycle became active.
Why it matters
Understanding when deep carbon cycling initiated helps scientists reconstruct how Earth's atmosphere, climate, and conditions for life evolved over geological time. This research provides constraints on when plate tectonics became sufficiently developed to drive carbon between Earth's surface and interior, which is fundamental to long-term planetary habitability.
Understand the Science
Proceedings of the National Academy of Sciences, Volume 123, Issue 38, September 2026. <br/>SignificanceUnderstanding when Earth’s deep carbon cycle began is critical for reconstructing planetary evolution and habitability. We add to this debate by integrating new zinc (Zn) isotopic data for Phanerozoic and Precambrian carbonatites plus …
Source: Zinc isotopic evidence for an Archean initiation of deep carbon cycling