Macros- are collections of frequently used commands which are grouped together in a file. Instead of entering commands individually, users can call the macro and the commands stored therein will be executed automatically. Macros may be stored in libraries .
Molten rock under the ground (often containing crystals and dissolved gases). Molten rock is called magma while it is still underground, but it becomes lava when it reaches the surface of the Earth.
Skinner B.J., S.C.Porter & J.Park (2004), DYNAMIC EARTH, 5th edition, Jon Wiley & Sons.
The process of altering the composition of a magma through the mixing of material from another magma body.
Tarbouk, E.J. & F.K. Lutgens, (2006), EARTH, 8th edition, Pearson Education International.