We have reappraised the age and composition of mid-Proterozoic Häme dyke swarm in southern Finland. The dominant trend dykes this is NW to WNW. Petrographic observations geochemical data indicate uniform, tholeiitic low- Mg parental magmas for all dykes. Nevertheless, variability incompatible trace element ratios, such as Zr/Y La/Nb, provides evidence changing mantle melting conditions variable...

Dykes are magma-filled fractures propagating through the brittle crust. Understanding physics of dyking process is essential to mitigate volcanic hazard associated with opening new eruptive fissures at surface. Often, physics-based models view either fracturing host rock or viscous flow magma as dominating energy sink during dyke propagation. Here, we provide a numerical model that captures cou...