StalGrowth—A Program to Estimate Speleothem Growth Rates and Seasonal Growth Variations

Abstract

Speleothems are one of the few archives which allow us to reconstruct the terrestrial paleoclimate and help us to understand the important climate dynamics in inhabited regions of our planet. Their time of growth can be precisely dated by radiometric techniques, but unfortunately seasonal radiometric dating resolution is so far not feasible. Numerous cave environmental monitoring studies show evidence for significant seasonal variations in parameters influencing carbonate deposition (calcium-ion concentration, cave air pCO2, drip rate and temperature). Variations in speleothem deposition rates need to be known in order to correctly decipher the climate signal stored in the speleothem archive. StalGrowth is the first software to quantify growth rates based on cave monitoring results, detect growth seasonality and estimate the seasonal growth bias. It quickly plots the predicted speleothem growth rate together with the influencing cave environmental parameters to identify which parameter(s) cause changes in speleothem growth rate, and it can also identify periods of no growth. This new program has been applied to multiannual cave monitoring studies in Austria, Gibraltar, Puerto Rico and Texas, and it has identified two cases of seasonal varying speleothem growth.

The impact of seasonal and event‐based infiltration on transition metals (Cu, Ni, Co) in tropical cave drip water

“…Such differences between drip sites can be interpreted as a different hydrological behavior linked to the recharge of the soil and the karst permeability network 19 . The main season of calcite precipitation in Larga Cave is the winter due to lower cave air pCO 2 45 . Therefore, speleothems beneath drip sites with appropriate transit times, that is, where the maxima in transition metal concentration occur during the main calcite precipitation (winter) season, are more likely to record transition metal variability than other sites.…”

“…Similarly, no significant seasonal variations were detected in the trace elemental ratios of Mg/Ca or Sr/Ca of the drip waters, which are often interpreted as hydrological proxies in speleothems 31,42–44 . Calcite precipitation rates respond to variations in both cave air pCO 2 and the Ca concentration of the drip water and are usually highest during the winter months when cave air pCO 2 is low 39,45 …”

“…31,[42][43][44] Calcite precipitation rates respond to variations in both cave air pCO 2 and the Ca concentration of the drip water and are usually highest during the winter months when cave air pCO 2 is low. 39,45…”

“…19 The main season of calcite precipitation in Larga Cave is the winter due to lower cave air pCO 2 . 45 Therefore, speleothems beneath drip sites with appropriate transit times, that is, where the maxima in transition metal concentration occur during the main calcite precipitation (winter) season, are more likely to record transition metal variability than other sites. Thus, drip sites C2, LA2, and LA4 may be more promising sites to record summer infiltration variability due to transit times of several weeks to months, whereas the response time of site SW2 may be too fast.…”

Technical note: „U-Th Analysis” – an open-source software dedicated to MCICPMS U-series-data treatment and evaluation

“…In contrast, in the deep part of the cave, where also stalagmite B1 was collected, ventilation is strongly muted, and cave air pCO2 values are higher with values up to 2300 -3600 ppm (Vieten et al, 2016). As a result of this ventilation regime, growth rates are expected to vary both seasonally, but also between different locations inside the cave (Vieten and Hernandez, 2021).…”