Teaching · geological supply

Rocks, dust, and vents move iron. The explorer still reports carbon and nitrogen.

Geology is the external supply story: desert dust, continental-margin sediments, and hydrothermal vents. Those pathways change how much iron biology can use. They are drivers, not headline tonnes. Flux Explorer reports tonnes of carbon and tonnes of nitrogen.

Three geological iron pathways

Each line is a published claim. The link is the paper. None of these is an Ocean Flux credit or a dosing rate.

PathwayWhat the literature saysLabel
Desert dust Desert dust is a major pathway delivering iron from land to the ocean. Jickells et al. 2005. The soluble fraction of that aerosol iron varies widely. Mahowald et al. 2005. Fact
Margin sediments Along a North Atlantic section, Saharan dust dominated dissolved iron, with additional contributions from margin sediments and Mid-Atlantic Ridge hydrothermal venting. Conway & John 2014. Fact
Hydrothermal vents Hydrothermal vents contribute dissolved iron to the oceanic inventory. Tagliabue et al. 2010. Dissolved hydrothermal metals can travel across the South Pacific at basin scale. Resing et al. 2015. Fact

How this sits with the explorer

  • Dust, sediments, and vents are complementary. A dust-only story is incomplete. Conway & John 2014.
  • Geological iron supply is a driver for biology. It does not become a tonne-of-iron headline, and it does not unlock a dose.
  • Reported outputs stay tonnes of carbon and tonnes of nitrogen, pathway by pathway. Air–sea carbon is transfer into the ocean, not burial.

Sources

  1. Jickells, T. D., et al. (2005). Global iron connections between desert dust, ocean biogeochemistry, and climate. Science. doi.org/10.1126/science.1105959
  2. Mahowald, N. M., et al. (2005). Atmospheric global dust cycle and iron inputs to the ocean. Global Biogeochemical Cycles. doi.org/10.1029/2004GB002402
  3. Conway, T. M., & John, S. G. (2014). Quantification of dissolved iron sources to the North Atlantic Ocean. Nature. doi.org/10.1038/nature13482
  4. Tagliabue, A., et al. (2010). Hydrothermal contribution to the oceanic dissolved iron inventory. Nature Geoscience. doi.org/10.1038/ngeo818
  5. Resing, J. A., et al. (2015). Basin-scale transport of hydrothermal dissolved metals across the South Pacific Ocean. Nature. doi.org/10.1038/nature14577

Disclaimer

Teaching page. Not verified carbon credits. Not commercial ocean iron fertilisation. Not a dosing playbook. See Disclaimer and Support.