Crustal folds alter local stress fields as demonstrated by magma sheet — Fold interactions in the Central Andes

For magma chambers to form or volcanic eruptions occur must propagate through the crust as dikes, inclined sheets and sills. Most models that investigate paths assume be either homogeneous horizontally layered, often composed of rocks contrasting mechanical properties. In regions have experienced orogenesis, like Andes, has been deformed over several million years, resulting in rock layers are commonly folded steeply dipping. The assumption properties horizontal layering then does not capture all potential path-crustal interactions. Here we tackle this problem by determining effect a made which sills emplaced. We combine field observations from sill emplaced core an anticlinal fold at El Juncal Chilean Central including lithologies, limbs attitude, length thickness with suite finite element method explore interactions between paths. Our results demonstrate host well contacts geometry crustal structures play important role propagation emplacement shallow levels. Sill heterogeneous anisotropic segments change stress promoting arrest, deflection further propagation. Specifically, more likely deflected when encountering dipping rather than fold. Mechanically weak encourage due related rotation is attenuated steeper. These processes may amount style recorded surface deformation, implications for monitoring active volcanoes.