Lithological controls on igneous intrusion-induced ground deformation

Ground deformation commonly precedes volcanic eruptions, although its relationship to underlying intrusion networks is complex.
We use 3D seismic reflection data to examine the link between a saucer-shaped sill and an overlying forced fold formed at
the contemporaneous palaeosurface. Our results highlight a disparity in size between the sill and fold, which we attribute
to accommodation of magma by overburden uplift and fluid expulsion from the host rock. Sill transgression occurred in response
to plastic deformation of the host rock and did not produce seismically resolvable uplift. Inversion models of ground deformation
should therefore acknowledge host rock behaviour during intrusion.

地壳变形通常先于火山喷发，尽管其与潜在侵入网络之间的关系复杂。本研究采用三维地震反射数据，探讨盘状岩床与同期古地表上形成的被迫褶皱之间的联系。研究结果表明，岩床与褶皱在尺寸上存在差异，我们将此归因于重覆层隆起对岩浆的容纳以及宿主岩石中流体的排出。岩床的侵入应答于宿主岩石的塑性变形，并未产生可由地震解析的抬升。因此，地壳变形的反演模型应承认宿主岩石在侵入过程中的行为。