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

The Neoproterozoic Solis de Mataojo Granitic Complex is an intrusive body, elongate north-south, emplaced in the Sarandi del Yi-Arroyo Solis Grande Sh ear Zone. In the present work, a quantification of the magmatic strain has been made by analysis of fabric, enclave geometry and minor structures. Str uctural evidence indicates that deformation began in the magmatic state and continued through the subsolidus stage. The observed distribution of magma tic foliations and lineations, the fabric, the geometry of the enclaves and the late to postmagmatic structures, are related to a non-coaxial flatteni ng regime that took place after the emplacement, and late in the magmatic h istory. These structures reveal that magmatic strain involved a shortening of the order of 80% with a simple shear component (gamma) between 3 and 4.5 . The solid-state deformation records an additional mean gamma of 2.7. (C) 2001 Elsevier Science Ltd. All rights reserved.