Speleothem Stable Carbon Isotope and its Application for Paleoclimatic and Paleoenvironmental Reconstructions:A Review

The investigations on speleothem stable carbon isotope (13C) are summarized. The factors influencing speleothem 13C, such as changes in vegetation (including C3 plant to C4 plant ratio and/or bio-productivity), soil processes, atmosphere CO2, karst grounder hydrology (including hydrodynamic of karst groundwater, water-rock interaction, prior calcite precipitation and etc.), are introduced one by one. Meanwhile some model simulations, which were used to quantitatively estimate the effects on speleothem 13C by specific factors such as dripping interval, cave ventilation intensity, flowing path and distance of groundwater and so on, are also introduced. According to the results of up to date researches on speleothem 13C, it is suggested that CO2 degassing of dripping water may be a key factor influencing speleothem 13C values and deserves more attention in future studies.