Melt migration and chemical differentiation by reactive porosity waves

Abstract

The different geodynamic settings with magmatism observed around the world, such as mid-ocean ridges (MORs), volcanic arcs and intraplate volcanism, indicate that asthenospheric melts are extracted under significantly distinct pressure, temperature and rheological conditions (Figure 1a). The main difference between melt extraction at intraplate settings and at MORs is the presence of the lithospheric mantle for the intraplate settings. The geochemical signature of MOR basalt (MORB) presumably depends on magma source composition, melt-extraction and differentiation processes intervening between the magma source and the crust (e.g., Langmuir et al., 1992). MORBs are produced and migrate in the asthenosphere and temperature (T) and pressure (P) variations are,