Integration of Geological, Mineralogical and Geochemical Methods in the Characterization of El Nitro and Las Alsacias Caves, Zapatoca (Colombia)

Abstract

The present study integrates geological, mineralogical and geochemical methods in the characterization of the caves: El Nitro and Las Alsacias, from Zapatoca (Colombia). With lithologies dating from the Lower Cretaceous, these cavities reveal a great variety of exokarst geoforms with different types of slips present on the surface, indicating changes in past atmospheric conditions. A great variety of speleothems (endokarstic geoforms) was also found, such as columns, stalactites, stalagmites, among others, which demonstrate a change in calcite saturation in the precipitated water. The morphology of the underground water bodies found showed variations in the dynamics of the karst aquifer (piezometric level and recharge), and it was evidenced that these cavities have structural control. The information obtained in the field (speleothematic catalogs, speleometry, maps, lithostratigraphy and structural data) were validated with atmospheric data and laboratory tests. This research provides new insights into geomorphology (epigeal and hypogeal), hydrogeology and mineralogy; serving as support for future work focused on paleoclimatic reconstruction, tectonic, paleosismic and climate change studies. These cavities represent scientific laboratories of great interest to the academy, since in them phenomena such as global warming and piezometric variations related to atmospheric phenomena can be evidenced.

Keywords

• Geomorphology
• karst
• hydrogeology
• petrography
• cartography