Microstructural and microchemical evolution of the Acquadolce serpentinites, Elba Island, Tuscany
This MSc project aims to improve our understanding of deformation processes and metamorphic evolution in the Acquadolce serpentinites of Elba Island (Northern Apennines, Italy). Elba preserves a well-exposed segment of an Alpine–Apenninic orogenic wedge in which ophiolitic units are tectonically juxtaposed against the Adriatic continental margin, bringing together serpentinites derived from different lithospheric domains and tectonic settings.
Supervisors
Main supervisor: Joachim Jacobs, UiB-GEO
Co-supervisor: Wolfgang Bach, University of Bremen
Co-supervisor: Sergio Rocci, University of Pisa
Project description
The Acquadolce serpentinites represent a structurally unique occurrence: a tectonised mantle slice that is not part of the classical ophiolite sequence but instead is sandwiched between continental units of the Adriatic margin. These rocks are closely associated with blueschist-facies metasedimentary units and record high-temperature deformation and recrystallisation. Their microstructural and mineralogical characteristics suggest deformation conditions that are comparatively high for typical Apenninic tectonics. This raises key open questions that the project will address:
- Do the Acquadolce serpentinites record deformation related solely to Apenninic subduction processes?
- Or do they preserve evidence for an earlier tectonic phase, potentially related to Alpine convergence?
- Alternatively, could their deformation and metamorphic record reflect processes associated with subduction initiation?
Preliminary electron microprobe analyses indicate the presence of multiple generations of clinopyroxene, including primary mantle relics and secondary metamorphic phases. These observations point to a complex, multi-stage deformation and metamorphic history that remains insufficiently resolved. The MSc project will focus on a detailed microstructural and microchemical investigation of the Acquadolce serpentinites, combining petrography with highresolution mineral chemistry. The main objective is to reconstruct deformation mechanisms and quantify element redistribution during progressive deformation and metamorphism.
The student will receive training in:
- Microstructural analysis (optical microscopy and SEM-based approaches)
- Electron microprobe analysis (quantitative point analyses)
- Element mapping and mineral chemistry interpretation
- Integration of microstructures and geochemistry into tectonic models
The project includes a small field component linked to the GEOV252 Geological Field Mapping course on Elba, where key sampling localities will be revisited and placed in their structural framework. This project will contribute to ongoing efforts to better constrain the tectono-metamorphic evolution of the Elba orogenic wedge and to evaluate competing geodynamic models for the Northern Apennines.
Field-, lab- and analysis work
Field work connected to Geov252 Geological Mapping, Elba Island