9526596 Essene This project involves petrological, geochemical, and isotopic studies of granulitic rock from different tectonic settings within the Sesia-Lanzo Zone (Western Alps) that record various degrees od transformations. Specific tasks include: (1) thermobarometric studies on eclogites, blueschists and greenschists to constrain the depths to which the rocks have been buried; (2) evaluation of the role of fluids in triggering the transformations between the facies; (3) reevaluation of thermodynamic data for typical eclogite/blueschist minerals and derivation of a new internally consistent petrogenic grid for blueschists and eclogites; (4) radiogenic isotopic studies (Sm-Nd and U-Pb) to establish the timing of the events and the influence of metamorphic transitions on the behavior of these systems. The results of this study will be important to evaluate discrepancies in the age of high pressure metamorphism in the Western Alps and will lead to a better understanding of deep crustal processes occurring during mountain building events in convergent tectonic zones.
