Tracking lithospheric delamination and surface processes across the Messinian salinity crisis.

Area of Science:

• Geology
• Tectonics
• Geochronology

Background:

• Lithospheric delamination is linked to surface uplift, magmatism, and extension.
• Delamination is hypothesized to have triggered uplift preceding the Messinian Salinity Crisis (MSC) in the Western Mediterranean.
• Previous studies lacked the temporal resolution to confirm delamination as the primary cause of MSC uplift.

Purpose of the Study:

• To investigate the timing and mechanisms of lithospheric delamination and its link to the Messinian Salinity Crisis.
• To resolve the temporal relationship between delamination, extension, and uplift in the eastern Betic intramontane basin.
• To understand the role of slab detachment in regional tectonic evolution.

Main Methods:

• U-Pb geochronology of calcite veins.
• Clumped isotope thermochronometry of calcite veins.
• Structural analysis of basin evolution.

Main Results:

• A brief fluid event occurred between 8.5 and 5 Ma, associated with extension and retreating delamination.
• Shortening and uplift commenced later, from 4.5 to 3 Ma, at the Africa-Iberia plate boundary.
• The Messinian Salinity Crisis predated the shortening phase and occurred during delamination.

Conclusions:

• Delamination initiated extension and uplift, triggering the Messinian Salinity Crisis.
• Slab detachment around 5 Ma led to the end of the MSC, formation of a new plate boundary fault, and tectonic escape.
• This study provides high-resolution dating to clarify the causal link between delamination and the Messinian Salinity Crisis.