Paleochannel and beach-bar palimpsest topography as initial substrate for coralligenous buildups offshore Venice, Italy

Area of Science:

• Marine geology
• Paleoceanography
• Bioconstruction

Background:

• Coralligenous buildups are significant marine carbonate structures.
• Their formation mechanisms in the Adriatic Sea remain incompletely understood.
• Holocene sea-level changes influenced coastal geomorphology and sedimentary processes.

Purpose of the Study:

• To model the genesis of Holocene coralligenous buildups.
• To investigate the paleoenvironmental conditions favoring their development.
• To link geomorphological evolution with bioconstruction processes.

Main Methods:

• High-resolution geophysical surveys (e.g., seismic, sonar).
• Underwater SCUBA diving for direct observation and sampling.
• Geological and sedimentological analyses of channel-levee systems.

Main Results:

• Identified meandering morphologies beneath Holocene buildups.
• Inferred these morphologies originated from Pleistocene fluvial systems.
• Dated lithification of sandy channel-levee systems to approximately 7,000 years BP.
• Proposed fluid-driven lithification due to freshwater-seawater interaction.

Conclusions:

• Ancient fluvial systems, reactivated as tidal channels, formed the foundation for coralligenous buildups.
• Lithified sandy deposits acted as nuclei for bioconstruction.
• This study provides a novel model for coralligenous buildup genesis in the Adriatic Sea.