Title: Paucity of mafic ring-dikes; evidence for floored polymagmatic chambers
Abstract: In monomagmatic chambers density differences between overlying country rock and magma should, following development of ring fractures, result in mafic ring dikes above mafic magma, and in foundering of the roof into felsic magma with the development of felsic stocks. The observed prevalence of felsic ring dikes may be due to shallow floors in felsic magma chambers, or to shallow constructed floors at the top of the mafic fraction in polymagmatic chambers.