The few available data suggest that silicon isotopes are fractionated during the production of opal by marine diatoms. Variations in silicon isotope ratios will be used to study diatom production and silica cycling in the ocean. A laser-based system will be used for determining silicon isotope ratios in inorganic and biogenic silicon-bearing phases to evaluate the utility of this approach by determining the fractionation factors for silica biomineralization and dissolution using cultures of Antarctic and temperature diatom species.
