The conceptual framework proposed by N.L. Bowen which describes the sequence in which minerals crystallize from a magma. The crystallization sequence can be divided into two series, the continuous series and the discontinuous series. The first minerals to form are the ultramafic minerals as they have the highest crystallization temperature. Mafic, intermediate, and felsic minerals follow, in order, as the melt gradually cools. Consequentially, the original magma's composition will evolve as temperature decreases, and the various minerals crystallize. It follows that crystallization temperature of igneous rocks can be estimated based on their mineralogical composition.