| Popis: |
The initial accumulation of magma within a partially-molten planetary mantle occurs in three stages. Within a mantle with evenly dispersed minerals the first melt is formed as small drops at grain corners and edges. By increasing degree of partial melting the drops of interstitial liquid become interconnected, whereafter the partially-molten mantle becomes permeable. At the onset of permeability the interstitial melt begins to accumulate in horizontal layers of melt situated tens of metres apart. These layers form the source of magma for the magma chambers that supply magma during eruptions. |
