Résumé
This study integrates new field geological-structural mapping, microstructural analysis, and quartz-feldspar crystallographic preferred orientation data obtained through electron backscatter diffraction (CPO-EBSD) of the Upper Triassic-Lower Jurassic Curaco Batholith (39 • 43′S-67 • 40′W) in northern extra-Andean Patagonia, Argentina. Field relationships, geometric-kinematic, and dynamic structural analysis indicate that the batholith's emplacement coincided with movements along an approximately E-W-trending dextral strike-slip brittle-ductile shear zone, influenced by regional NE-SW oblique extension and pre-existing NW-SE-trending Paleozoic basement fabric. The alternation of igneous intrusions and deformation structures is consistent with its syntectonic emplacement by incremental growth of a pluton-dike system, fed by multiple small injections during a singlephase progressive transtensional event. The internal structural fabric gradually transitions from magmatic to sub-magmatic flows and from high-to low-temperature solid-state ductile-brittle deformation at all scales, indicating melt-present deformation and progressive fabric development under changing deformation conditions. As the batholith cools and crystallizes, the preferred shape orientations of minerals in the fabrics change, successively controlled by magmatic and tectonic processes. Combining published and new zircon U-Pb dates of 224-183 Ma provides constraints on the timescale of these tectono-magmatic processes, which are spatially and temporally related to regional intracontinental deformation in northern Patagonia during the early stages of the breakup of western Gondwana.