Organic geochemistry and mineralogy suggest anthropogenic impact in speleothem chemistry from volcanic show caves of the Galapagos
This study delves into the microbial, isotopic, and mineralogical characteristics of speleothems in volcanic caves. In Bellavista Cave, filamentous and rod-shaped microbial structures with extracellular polymeric substance (EPS) biofilms were identified, along with bacterial families capable of influencing the nitrogen cycle. The organic fraction composition in Royal-C revealed an intermediate carbon isotope composition, potentially linked to C3/C4 plants or microbial activity, while a high d15N value indicated anthropogenic alterations. The mineralogical analysis of speleothems unveiled unique structures in moonmilk and coralloid formations, with the presence of organic molecules associated with