Generic and Environmental Control of Carbonate Mineralogy in Serpulid (Polychaete) Tubes

Abstract

Calcareous tubes of the polychaete family Serpulidae are composed of magnesian calcite, aragonite, or mixtures of these two minerals. Mineralogy is controlled principally by generic factors, but may be modified-at least in some genera-by environmental factors. The percentage of aragonite in most serpulid tubes shows little or no correlation with water temperature. The $$MgCO_{3}$$ concentration in the entirely calcitic tubes generally increases with increasing temperature, but the $$MgCO_{3}$$ content in the calcite of tubes with mixed mineralogy appears to be dependent upon mineralogy-that is, as aragonite content increases, the magnesium carbonate within the calcite also increases so that the magnesium within the entire tube remains about constant. In tubes with more than 60% aragonite, however, the total magnesium content drops markedly.