Measurement and interpretation of strain in the syntectonic Solı́s de Mataojo Granitic Complex, Uruguay

The Neoproterozoic Solı́s de Mataojo Granitic Complex is an intrusive body, elongate north–south, emplaced in the Sarandı́ del Yı́–Arroyo Solı́s Grande Shear Zone. In the present work, a quantification of the magmatic strain has been made by analysis of fabric, enclave geometry and minor structures. Structural evidence indicates that deformation began in the magmatic state and continued through the sub-solidus stage. The observed distribution of magmatic foliations and lineations, the fabric, the geometry of the enclaves and the late to post-magmatic structures, are related to a non-coaxial flattening regime that took place after the emplacement, and late in the magmatic history. These structures reveal that magmatic strain involved a shortening of the order of 80% with a simple shear component (γ) between 3 and 4.5. The solid-state deformation records an additional mean γ of 2.7.