Abstract

Strike-slip faults are commonly assumed to influence magma transport and emplacement in the Earth's crust. However, direct observations of magma conduits within strike-slip faults are lacking. Here we provide some of the first detailed field observations of dykes emplaced within strike-slip faults in the Neuquén Basin, Argentina. We show how fault planes within strike-slip fault zones affect the emplacement of dyke offshoots, resulting in complex dyke morphology. Our study also emphasizes the importance of pre-existing strike-slip fault array on the development of dyke swarms, showing that orientations of dyke swarms may not systematically relate to the principal tectonic stress axes.