Trace Elements in Speleothems as Indicators of Past Climate and Karst Hydrochemistry: A Case Study from Kaite Cave (N Spain)

A stalagmite that grew during the Holocene (between 4.9 and 0.9 ka BP) in Kaite Cave (Ojo Guarena Karst Complex, Burgos, N Spain) has been analyzed by Laser-Induced Breakdown Spectroscopy (LIBS) with the aim of reconstructing secular variations in the hydrochemistry of the karst system, in turn related to changes in the environment outside the cave. LIBS analyses yield significant changes in Mg/Ca and Sr/Ca intensity ratios through the stalagmite, which reveal consistent trends and patterns at decadal to centennial scales. The origin of the observed changes in Mg/Ca and Sr/Ca ratios is discussed in the framework of the cave system and the regional climatic variability, particularly the changes in precipitation.