Felsic magmas are formed within the crust, usually through the melting of crust rock from the heat of underlying mafic magmas. The lighter felsic magma floats on the mafic magma without significant mixing. Less commonly, felsic magmas are produced by extreme fractional crystallization of more mafic magmas. This is a process in which mafic minerals crystallize out of the slowly cooling magma, which enriches the remaining liquid in silica.
Felsic magmas are formed within the crust usually through the melting of crust rock from the heat of underlying mafic magmas The lighter felsic magma floats on the mafic magma without significant mixing Less commonly felsic magmas are produced by extreme fractional crystallization of more mafic magmas This is a process in which mafic minerals crystallize out of the slowly cooling magma which enriches the remaining liquid in silica