Dynamic processes occur during filling of the magma chamber or during its crystallization. They include differential settling or flotation of crystals with contrasted densities and/or grain sizes, flow segregation of crystal-laden magma and crystal segregation during convective liquid movement into the magma chamber. Double diffusive convection, which produces a stratified liquid column in the magma chamber, can also produce layering. Other dynamic processes include magma injection into the chamber, which results in magma stratification or magma mixing, and silicate liquid immiscibility either in the main magma chamber or within the solidifying crystal mush.
Non-dynamic layer-forming processes mainly include rapid changes in intensive conditions of crystallization (e.g. pressure, oxygen fugacity) that disrupt and change the stable liquidus assemblages, and transitory excursions about cotectic curves. Layering can also result from variation in nucleation rates and from mineral reorganization in a crystal mush through grain rotation, dissolution-precipitation due to initial heterogeneity in terms of grain size distribution, mineral modes or differential pressure. Many of these processes are driven by dissipation of energy and can be referred to as equilibration or self-organization processes.
|Redaktører||Bernard Charlier, Olivier Namur, Rais Latypov, Christian Tegner|
|ISBN (Trykt)||978-94-017-9651-4, 978-94-024-0655-9|
|Status||Udgivet - 2015|
- Programområde 4: Mineralske råstoffer