Prof. Dr. Stephen F. Foley

Research Interests

My research interests concern the origin and compositions of magmas and igneous rocks. Two types of melts are of particular interest, namely the origin of alkaline melts by partial melting of the Earth's mantle, and the origin of the early continents by partial melting of the Earth's crust. Alkaline melts differ from the more common basalts - they require melting of source rocks other than peridotite, which is thought to be the main constituent of the Earth's mantle. These other source rocks are rich in minerals such as clinopyroxene and mica, and need considerable further research before we understand their importance in melt formation. The continental crust formed in Archaean times (the first half of Earth history) is more sodium-rich than crust that formed later, and the reasons for this are debated. The early crust is complex and mixed up by later processes, so that explaining its formation is challenging. My research combines petrology with major and trace element geochemistry and high-pressure experiments. Further interests lie in the origin, stabilization and breakup of cratons, which are the older, stable cores of the continents, and in the evolution of magma compositions and magmatic processes throughout Earth history. Understanding the changing processes and melt compositions through time is essential to a full understanding of the earth system.