Melting relations

Abstract

The process of magma generation with subsequent uprise and intrusion or extrusion of magma is one of the fundamental processes in the evolution of the earth. Rheological and other physical properties change markedly wherever and whenever partial melting occurs. The melting relations of minerals and rocks can now be measured in the laboratory to pressures corresponding to depths of more than 250 km. The measurements provide limits for temperatures within the earth and a basis for extrapolation to greater depths. This report outlines experimental results for the melting of elements, minerals, and rocks under various conditions, in a dry state or in the presence of water and other volatile components. There is overlap with reports on experimental petrology in another section, but it is reduced to a minimum by limiting this review to melting curves and properties, without attention to the more detailed aspects of petrogenesis.