Anoxic and oxic phototrophic primary production during the Precambrian

TY - GEN

T1 - Anoxic and oxic phototrophic primary production during the Precambrian

AU - Ebey-Honeycutt, Christina Marie

AU - Bjerrum, Christian J.

AU - Canfield, Donald Eugene

N1 - Conference code: 19

PY - 2009

Y1 - 2009

N2 - Large areas of the oceans were reducing during much of the Precambiran  (4.5 to 0.5 Ga). The Great Oxidation Event (GOE; 2.45-2.2 Ga )  most likely was associated with the establishment of a redox-cline at the base of the surface mixed layer of the ocean.  In the modern ocean, the bottom of the mixed layer often lies above the base of the photic zone . Thus, an ecosystem model for the Precambrian should reflect the net primary production (NPP) of oxygenic phototrophs in the mixed layer and anoxygenic phototrophs below (NPPox and NPPred, respectively). Satelite data and a vertically generalized production model (VGPM) can be used to calculate the mixed layer NPP relative to the NPP below. We use this to estimate the potential role of NPPred below the mixed layer. The model implies that ~34% of the Precambrian total NPP would have been NPPred if factors such as climate were comperable to today. High rates of exported NPPred are consistent with the Precambrian sulfur isotope record which suggests that high rates of sulfate reduction proceeded the GOE.    Figure: Results of the model of anoxigenic photosynthesis. Percent is relative to total production.

AB - Large areas of the oceans were reducing during much of the Precambiran  (4.5 to 0.5 Ga). The Great Oxidation Event (GOE; 2.45-2.2 Ga )  most likely was associated with the establishment of a redox-cline at the base of the surface mixed layer of the ocean.  In the modern ocean, the bottom of the mixed layer often lies above the base of the photic zone . Thus, an ecosystem model for the Precambrian should reflect the net primary production (NPP) of oxygenic phototrophs in the mixed layer and anoxygenic phototrophs below (NPPox and NPPred, respectively). Satelite data and a vertically generalized production model (VGPM) can be used to calculate the mixed layer NPP relative to the NPP below. We use this to estimate the potential role of NPPred below the mixed layer. The model implies that ~34% of the Precambrian total NPP would have been NPPred if factors such as climate were comperable to today. High rates of exported NPPred are consistent with the Precambrian sulfur isotope record which suggests that high rates of sulfate reduction proceeded the GOE.    Figure: Results of the model of anoxigenic photosynthesis. Percent is relative to total production.

M3 - Conference article

SN - 0016-7037

SP - A549

JO - Geochimica et Cosmochimica Acta

JF - Geochimica et Cosmochimica Acta

IS - 12

T2 - Goldschmidt Conference

Y2 - 21 June 2009 through 26 June 2009

ER -