As rapidly precipitating freshwater carbonate accumulations that form in equilibrium with ambient water, tufas represent potential sources of high-resolution paleoenvironmental records. To critically examine the use of tufa isotopic records in such reconstructions, Osácar et al. examine a 12-year record of a modern tufa system, comparing water δ18O with δ13C and δ18O signatures in the precipitates. The data illustrate that these tufas mimic seasonal temperature changes, but that the pattern is complicated by changes in the isotope record of precipitation. These results are interpreted to illuminate the complex interaction of factors operative at several different type scales (seasonal and annual) that must be evaluated to accurately understand the isotopic record of ancient tufa systems.
Environmental Factors Controlling the δ13C and δ18O Variations of Recent Fluvial Tufas: A 12-Year Record from the Monasterio de Piedra Natural Park (NE Iberian Peninsula) by M. Cinta Osácar, Concha Arenas, Marta Vázquez-Urbez, Carlos Sancho, Luis F. Auqué, and Gonzalo Pardo