Richard Walker , Simon Philip Gill 

Igneous sills are common features in tectonically active regions, acting as nascent magma storage systems, or feeding eruptions at large lateral distances from the magma source. Sills reaching a critical radius, rc, relative to their initial depth, H, interact with Earth’s surface, leading to mild discordant growth at angle [theta] typically <10[deg] forming saucer-shaped sills; commonly rc>3H for natural sills. Analogue and numerical models for sills produce saucer shapes where [theta] >10[deg] and rc