Who is Donald Canfield and what is the Canfield ocean?

Donald Canfield is an American geochemist and geologist known for studying the evolution of Earth's atmosphere and oceans. He proposed the Canfield ocean model in 1998 to describe deep-water conditions during the Proterozoic eon. This model suggests that ancient oceans featured anoxic and sulfidic bottom waters beneath a thin oxygenated surface layer.

What we know

• Donald Canfield is an American geologist and geochemist born in 1957 who serves as a Professor of Ecology at the University of Southern Denmark. [1, 2]
• The Canfield ocean model was proposed by Donald Canfield to explain the composition of oceans during the middle to late Proterozoic eon. [2, 3, 5]
• The Canfield ocean model includes euxinic deep water, meaning the water is completely lacking in oxygen and contains raised levels of free hydrogen sulfide. [5]

Still open

• There is ongoing debate within the scientific community regarding both the duration and the frequency of euxinic conditions in ancient oceans.

Where to go next

• how it workedWhat are euxinic water conditions?
• the bigger pictureWhat was the Proterozoic eon?
• what caused itHow did Earth's atmosphere evolve?
• a case in pointWhich modern bodies of water feature euxinic conditions?
• whereUniversity of Southern Denmark department of ecology
• an unexpected connectionHow does the Black Sea relate to ancient Proterozoic oceans?The Black Sea serves as a modern geographic example of euxinic, strongly stratified water conditions that mirror Donald Canfield's model of ancient deep ocean chemistry.

Sources

• [1]Donald Canfield (Wikidata Q5294150) · CC0 1.0
• [2]Donald Canfield · CC BY-SA 4.0
• [3]Canfield ocean · CC BY-SA 4.0
• [4]Canfield (surname) · CC BY-SA 4.0
• [5]Euxinia · CC BY-SA 4.0