Benthic foraminifera vital effects

This Waterloo was unfortunate for the author considers the boron method to be basically sound and potentially extremely powerful. The answer to the benthic enigma may lie in species-to-species differences in the boron isotope vital effect for benthic foraminifera. The measurement method use by Sanyal et al. (1996) required a large number of benthic shells in order to get enough boron to analyze. This created a problem because, as benthics are rare among foraminifera shells, mixed benthics rather than a single species were analyzed. If the boron isotope pH proxy is to... 

Grossman E. L. (1987) Stable isotopes in modem benthic foraminifera a study of vital effect. J. Foraminiferal Res. 17(1), 48-61. 

Covariation between 8 C and 8 0 values in benthic foraminifera is well known, and is generally attributed to vital effects such as variations in... 

Grossman, E. L. 1987. Stable isotopes in modern benthic foraminifera a smdy of vital effect. Journal of Foraminiferal Research, 17, 48—61. 

The incorporation of oxygen isotopes into biogenic carbonate is complex and as Wefer et al. (1999) point out, the 8 0 value of a carbonate is a function of temperature, ice volume, selective growth in space and time, vital effects and post-depositional dissolution. The carbonate chemistry and pH of a benthic foraminifera s microenvironment or microhabitat also plays an important role in test isotopic composition (e.g. Spero et al. 1997 Bemis et al. 1998 Bijma et al. 1999 Wolf-Gladrow et al. 1999), with a 0.2 increase in pH resulting in a 8 0 shift of approximately — 0.22%o (Zeehe 1999). 

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