Rapid viscous flow of crustal rocks controls dyke emplacement in the ductile crust.

ABSTRACT: Magmatic dykes are the main pathways for magma through Earth's crust. They are often assumed to be magma-filled fractures that propagate as thin, tapered sheet intrusions through mode I tensile opening at the fracture tip and elastic bending of the host rock along the dyke walls. Here, we present field evidence from northern Sweden, showing that deep-crustal dyke emplacement was, despite high strain rates, associated with significant ductile deformation of the host rocks. On average, 25% of the dyke thickness was accommodated by ductile flow of the immediate host rock. Modelling magma cooling times suggests average ductile strain rates of 10^-3 s^-1 to 10^-6 s^-1, i.e. 6 to 10 orders of magnitude faster than typical tectonic ductile strain rates in t

SUBMITTER: Kjoll HJ 

PROVIDER: S-EPMC12824300 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature