Highlights
- Two mineral crusts were discovered in San Teodoro Cave (Sicily)
- The oldest is a white crust (calcite and phosphate) overlying a Late Pleistocene fossil deposit
- A sterile sediment layer separates it from the upper crust
- The upper crust is reddish-brown and formed by aragonite and phosphates
Abstract
The mineralogical and geochemical composition of cave sediments provides crucial insights into past climatic and biological dynamics. This study investigates the authigenic crusts of San Teodoro Cave (Sicily), a key Upper Pleistocene palaeontological site, through a multi-analytical approach.The cave hosts two superimposed phosphatic crusts, separated by sterile sediment, reflecting shifts in depositional and post-depositional conditions. Our analyses reveal a complex mineral assemblage consisting of calcite, aragonite, and various phosphate phases. Calcite is the dominant phase in the older crust, whereas the presence of aragonite in the younger brown crust likely indicates periods of increased aridity, potentially corresponding to conditions during the Last Glacial Maximum. Aragonite precipitation was favoured by elevated Mg/Ca ratios, limited water infiltration, and kinetically controlled processes. Phosphate minerals, derived from bat guano, record localised pH variations and biologically mediated geochemical activity. The development of stable crusts without evidence of bioturbation further suggests the cessation of hyena activity within the cave. These findings demonstrate that the aragonite-phosphate association is a probable indicator of extreme dryness and specific taphonomic pathways in Mediterranean Pleistocene cave environments, offering a high-resolution proxy for paleoenvironmental reconstruction during the driest phases of the Late Pleistocene.
DOI
https://doi.org/10.5038/1827-806X.ijs2597
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 4.0 License.
Recommended Citation
Vita, G., Saladino, M.L., Armetta, F., Calabrese, N., Sineo, L., 2026. Geochemistry of crusts in paleontological deposits: taphonomic settings in an Upper Pleistocene cave site (San Teodoro, Sicily). International Journal of Speleology, 55(1), ijs2597. https://doi.org/10.5038/1827-806X.ijs2597
