INTEGRATED GEOBIOLOGICAL AND WATER GEOCHEMISTRY APPROACH FOR THE IDENTIFICATION OF ENVIRONMENTAL PROXIES IN CORALLIGENOUS BIOCONSTRUCTIONS

This study presents a comprehensive investigation of coralligenous build-ups located offshore of Marzamemi, combining petrographic, mineralogical, and geochemical analyses of the carbonate components with the geochemical characterization of the surrounding seawater. The identification of newly observed elemental fractionation patterns within mineral phases in equilibrium with seawater provides a novel approach for detecting both natural and anthropogenic environmental perturbations in marine systems. These geochemical signatures can be preserved over time, offering valuable insights into past and present changes in water chemistry.Within this framework, coralligenous bioconstructions - complex biogenic structures that play a key role in Mediterranean benthic ecosystems - were specifically analyzed to assess their internal composition, mineral assemblages, and textural features. Special attention was given to the geochemical signatures of these components, which offer further insights into the processes governing their formation and underscore their potential as long-term environmental archives.Our findings contribute to a deeper understanding of the environmental significance of coralligenous frameworks, emphasizing their potential as geochemical archives in shallow-marine environments. The strong correlation observed between the composition of both skeletal and non-skeletal carbonate components and that of the surrounding seawater suggests that coralligenous build-ups can serve as reliable indicators of present and past environmental conditions, as well as of temporal geochemical variations. This integrated approach represents a significant advancement in our understanding of the interactions between bioconstructions and the marine environment, opening new avenues for the monitoring, reconstruction, and preservation of marine and coastal ecosystems. Moreover, the methodology applied in this study may be effectively extended to similar environmental settings worldwide, offering a valuable tool for assessing both current and past conditions in diverse shallow-marine systems.