The Canfield Ocean model was proposed by geochemist Donald Canfield to explain the composition of the ocean in the middle to late Proterozoic. His theory has been coined the 'Canfield Ocean' and remains one of the cornerstone theories of ocean oxygen composition during that time.
In a seminal paper published in 1998 in Nature, Canfield argued that the ocean was anoxic and sulfidic during the time of the Boring Billion, and that those conditions affected the mineral deposition of iron-rich Banded iron formations (BIF). Prior to the Canfield Ocean theory, it was believed that the ocean became oxygenated during the Great Oxygenation Event. The presence of oxygen in the deep ocean made the formation of BIF impossible, which is seen in ocean sediment records. Conversely, the Canfield Ocean theory postulates that deep ocean water remained anoxic long after the Great Oxidation Event, and he argued that the euxinic conditions in the deep ocean ceased the deposition of BIF in ocean sediments.
Euxinic describes anoxic conditions in the presence of H
2S hydrogen sulfide. Euxinic ocean conditions, a term describing restricted hydrologic circulation that lead to stagnant or anaerobic conditions, are the likely factor leading to sulfidic oceans.
- Anoxic event – Intervals in the Earth's past where parts of oceans were depleted of oxygen at depth over a large geographic area
- Hypoxia – Low environmental oxygen levels
- Boring Billion – Between 1.8 and 0.8 billion years ago
- Mass extinction – Widespread and rapid decrease in the biodiversity on Earth
- Ocean stratification – Stable water layers of different properties that act as a barrier to vertical mixing
- Permian–Triassic extinction event – Most severe extinction event of Earth's chronology
- Suess effect
- Canfield, D.E. (1998). [Abstract PDF "A new model for Proterozoic ocean chemistry"] Check
|url=value (help). Nature. 396 (6710): 450–453. Bibcode:1998Natur.396..450C. doi:10.1038/24839.
- Holland, Heinrich D. (2006-06-29). "The oxygenation of the atmosphere and oceans". Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences. 361 (1470): 903–915. doi:10.1098/rstb.2006.1838. ISSN 0962-8436. PMC 1578726. PMID 16754606.
- Timothy W. Lyons; Ariel D. Anbar; Silke Severmann; Clint Scott & Benjamin C. Gill (January 19, 2009). "Tracking Euxinia in the Ancient Ocean: A Multiproxy Perspective and Proterozoic Case Study". Annual Review of Earth and Planetary Sciences. 37 (1): 507–53. Bibcode:2009AREPS..37..507L. doi:10.1146/annurev.earth.36.031207.124233.