magma
/ˈmaɡmə
/noun (plural magmas or magmata /ˈmaɡmətə/) [mass noun]
Hot fluid or semi-fluid material below or within the earth’s crust from which lava and other igneous rock is formed on cooling: when red-hot magma comes into contact with seawater, an explosion results [count noun]: basaltic magmas are normally expelled at the surface in a very hot and fluid state...
- Massive sulfide deposits may also form in other settings where water circulates in rocks near cooling magma.
- What they do know is that a ‘slow rise’ of magma is driving lava to the surface, which has created a new lava dome in the mountain's crater.
- Melts form at the highest temperatures and lowest pressures resulting in large volumes of tholeiitic magma that form shield volcanoes such as Mauna Loa.
Derivatives
magmatic
/ adjective ...- In central and northern Sardinia there is evidence of an Ordovician magmatic belt upon older basement interpreted as an Andean-type volcanic arc.
- Thin-section analysis shows that the minerals forming the magmatic foliation do not show any signs of deformation or recrystallization.
- Rifting was associated with magmatic activity.
Origin
Late Middle English (in the sense 'residue of dregs after evaporation or pressing of a semi-liquid substance'): via Latin from Greek magma (from massein 'knead').