Magnesium in Calcite From a Coralline Alga

Abstract

ABSTRACT Analyses of calcite from field-collected and laboratory cultured specimens of the articulated coralline alga Calliarthron tuberculosum indicate that temperature is not an independent factor controlling the magnesium content of the calcite. Growth rate, which appears to be a function of temperature, is probably the mechanism responsible for changes in the magnesium content. Changes in growth rate may effect changes in the magnesium content of the calcite through the interaction of factors such as the diffusion rate of magnesium through the cell wall and the construction of an organic matrix or template.