Abstract
The mechanism of development of shallow magma chambers and their relationships with caldera collapse are poorly known. Here we review the studies of pluton emplacement and caldera collapse, proposing a model linking the two processes. Magma ascending through diapirs or dikes is mostly halted at middle crustal levels. In the upper crust, the further rise of magma occurs by diking and the emplacement occurs along major anisotropies. Many plutons are emplaced at subhorizontal discontinuities, consisting of tabular, sill-like intrusions. Their growth will eventually induce doming of the overburden, forming laccoliths. Various evidence for shallow felsic and mafic laccoliths have been provided, suggesting that laccoliths are the most common mechanism to store magma in the upper crust, especially when the magmatic rates exceed the tectonic ones.
