Condensation corrosion alters the oxygen and carbon isotope ratios of speleothem and limestone surfaces

Condensation corrosion is a natural process which enhances the chemical weathering of limestone cave chambers and speleothems. We evaluated use carbonate tablets for detecting condensation in Glowworm Cave, New Zealand, using local speleothem as experimental substrates (herein tablets). Evidence was assessed via three methods: gravimetric (mass wasting), microscopic (surface pitting, recrystallization) isotopic (δ13C δ18O changes). Our results show little evidence tablet mass loss throughout 6-month deployment period. However, SEM imaging isotope analysis δ18O) upper ~50 μm layer tablets, suggest that operates cave, especially sectors affected by large diurnal microclimate variations. Most notably, water altered surface δ13C values. Small, positive shifts values are considered to reflect pure dissolution (where favours removal lighter isotopologues). In contrast, exhibited tandem with negative values, interpreted showing calcite recrystallization inheritance higher DIC (13C fractionation CO2 degassing), and/or kinetic δ18O. This study therefore demonstrates stable isotopes could be applied detect paleoclimatic episodes