A Journey toward the High-Pressure Metamorphism in Continental Crust: P-T-D Path Estimate and 40Ar/39Ar Single Grain Dating on Muscovite of a Tectonic Unit along the Western Edge of the Alpine Corsica (France)

Abstract

The first attempt of pressure-temperature-deformation-time (P-T-d-t) path reconstruction for the Lower Units (Alpine Corsica, France) is presented in this work. The Lower Units represent, together with the Tenda Massif, fragments of the European continental margin involved into the east-dipping Alpine subduction. The new data of thermobarometry applied on metapelites and the new 40 Ar/ 39 Ar dating of syn-kinematic muscovite sampled into a metagranitoids allowed to define the P-T conditions and the age of the metamorphism of Venaco Unit, a Lower Unit located in the southernmost sector of the Alpine Corsica. The outcoming scenario indicates that the Venaco Unit reached the baric peak at [?] 33 km of depth not before the Bartonian time. At 35.7 Ma (i.e., during the middle Priabonian), it was exhumed at shallower structural level (i.e., at [?] 26 km of depth) mainly through the activation the top-to-the W shear zones. This retrograde path suggests that Venaco Unit experienced a fast exhumation, unlike the Tenda Massif which has already involved into subduction during the Ypresian and stationed at 25-30 km before its exhumation in the Priabonian.Hosted file mdr solidearth_suppinfo.docx available at https://authorea.com/users/548827/articles/603261a-journey-toward-the-high-pressure-metamorphism-in-continental-crust-p-t-d-pathestimate-and-40ar-39ar-single-grain-dating-on-muscovite-of-a-tectonic-unit-along-thewestern-edge-of-the-alpine-corsica-france Hosted file essoar.10512123.1.docx available at https://authorea.com/users/548827/articles/603261-ajourney-toward-the-high-pressure-metamorphism-in-continental-crust-p-t-d-path-estimateand-40ar-39ar-single-grain-dating-on-muscovite-of-a-tectonic-unit-along-the-westernedge-of-the-alpine-corsica-france